# Getting serious about lo-pro



## mtngun

This subject of running lo-pro chain on milling bars has been hashed out again and again, yet there is still no consensus. The only thing we have agreed upon is that Stihl/Logosol picco is different than Oregon/Carlton lo-pro. 

Because I've started to lay out some money to convert my 36" mill to lo-pro, I'm going over the subject with a fine tooth comb. I'm planning to run the Carlton/Oregon stuff, so my investigation only concerns Carlton/Oregon and not the Stihl/Logosol picco. Here's what I've found and some of this will be old news, so bear with me. 

Since Carlton makes lo-pro ripping chain, I contacted Carlton and asked if I could run their lo-pro on my "regular" 3/8 bars and sprockets. Carlton has yet to reply. 

One of our members, Matilda's Mate, once posted that a Carlton rep gave him the green light to run Carlton lo-pro on "regular" 3/8 bars and sprockets. While I believe Matilda's Mate, I suspect that Carlton's lawyers will frown on putting that advice in writing, for liability reasons.

I also contacted Oregon, and they do not "_advise_" running lo-pro 3/8 on "regular" 3/8 sprockets and bars. 

At first, Oregon flat out said that the two types of chain were not "_compatible_."

With some prodding, the Oregon rep admitted that 0.050" lo-pro would run fine on an 0.050"_ hard nose_ bar. Most of us don't like hard nose bars, but still, that is an option for us.

I asked if they could recommend a lo-pro rim sprocket that fits a Stihl 066. No, they don't make such a sprocket and they "_advise_" against using a regular 3/8 rim sprocket "_as the drive link will not seat down into the sprocket correctly_."

As has been posted before, here's a pic of Oregon lo-pro chain on a "regular" 3/8 rim sprocket. Gentlemen, I can't think of any reason why this won't work ?






Oregon also advised against running lo-pro on a "regular" 3/8 nose sprocket, because "_there is increased risk of the chain jumping off the bar when using the incorrect chain_." 

My gut feeling is that Oregon is being throttled by their lawyers, for liability reasons, so I don't necessarily believe everything that Oregon is saying.

Bailey's sells the Carlton lo-pro ripping chain, and surely they realize that people are using it on large milling saws. The Baileys web site says that lo-pro should only be used on saws that were designed for lo-pro (lawyer talk), yet one of their FAQs said it was OK to run lo-pro on "regular" 3/8 bars and sprockets. Huh ?

I asked Grande Dog to clarify. He expressed some concern about the nose sprocket causing stretch. Grande Dog usually knows what he is talking about. 

I was concerned enough to mill a nose sprocket such that I could view how the chain was meshing with the sprocket. 

Here is the modified sprocket, a well used "regular" 3/8 Windsor nose sprocket with new "regular" 3/8 chain. Note the drive link meshes nearly perfectly with the sprocket teeth.





Here is Oregon lo-pro on the "regular" 3/8 nose sprocket. Note there is little contact between the drive link and the sprocket. The chain appears to be supported on the very tip of the sprocket .......





....... like this.





So..... I concede that the fit of lo-pro on a "regular" 3/8 nose sprocket is seriously flawed, and it will probably increase chain stretch. 

I'm_* guessing*_ that if you ran lo-pro on the sprocket long enough, the sprocket teeth would eventually "wear in" to fit the lo-pro decently.

Also, bear in mind that the nose sprocket is merely an "idler," it does not transmit torque. It doesn't "work" as hard as the drive sprocket.

The bottom line is that several CSM'ers are running lo-pro on "regular" 3/8 bars and the only complaint is more stretch.


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## SilverBox

Nice pics!. 

I didn't see that you addressed the strength issue thu. 3/8ths lo pro is likely to break quite often on a big saw (60+ cc). The more power you have the more likely you are to break it. Technique will of course be able to compensate some for this. Slow application of throttle and very even and uniform pushing that is never super hard should help to minimize chain breakage, but I imagine you'll still snap a few.

So far as set up, looks like it will work just fine to me, but your gonna snap a few chains before you figure out how hard you can push and how abrupt you can be with the throttle. 

I've broken cheapie 3/8ths lopro on a 2 horse saw bucking 12" oak rounds several times, quality 3/8ths lopro (oregon) I've run to the end of the chains life on a 3 horse saw (many times).. 

The transition point from lopro to real 3/8ths seems to be in the 3-4 horse range.

Your 660 is a 7 horse saw stock, thats probably double the power 3/8ths lopro is designed for.


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## SilverBox

The other issue aside from the strength and fit of the chain in my mind anyways is will it really be faster. If your goal is to save time, I'm not so sure lopro will be effective, if your goal is to save wood, for sure it has a smaller kerf.


On the issue of saving time:

It seems likely that with smaller logs (with a 660, (I use a 394 about the smae power as a 660), I'd guess on 16" or less would be smaller) you won't really see much of a difference. I'm figuring this based on the fact that the raker height will probably be the same, so your shaving off the same amount of wood with each revolution of the chain regardless of kerf width, on smaller wood with a bigger saw your rpm in the cut will likely be very similar as you'll have enuf power to run full tilt with either size kerf.

In bigger logs is where I think the lopro might shine, but it will also be the max stress situation where its likely to break chains which will cost you time to deal with. The loss of time from dealing with broken chains might actually make it slower to mill with


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## BobL

SilverBox said:


> The other issue aside from the strength and fit of the chain in my mind anyways is will it really be faster. If your goal is to save time, I'm not so sure lopro will be effective, if your goal is to save wood, for sure it has a smaller kerf.
> 
> On the issue of saving time:
> It seems likely that with smaller logs (with a 660, (I use a 394 about the smae power as a 660), I'd guess on 16" or less would be smaller) you won't really see much of a difference. I'm figuring this based on the fact that the raker height will probably be the same, so your shaving off the same amount of wood with each revolution of the chain regardless of kerf width, on smaller wood with a bigger saw your rpm in the cut will likely be very similar as you'll have enuf power to run full tilt with either size kerf.
> 
> In bigger logs is where I think the lopro might shine, but it will also be the max stress situation where its likely to break chains which will cost you time to deal with. The loss of time from dealing with broken chains might actually make it slower to mill with



All this is why I'm limiting my lp setup to a 441 with a 25" bar for small logs


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## Philbert

Great post - really helpful photos.

Thanks.

Philbert


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## mtngun

SilverBox said:


> your rpm in the cut will likely be very similar as you'll have enuf power to run full tilt with either size kerf.


Perhaps a strong 066 at sea level has enough power to run full tilt with regular 3/8, but my 066 sure doesn't. It struggles to maintain 9000 rpm in the cut on small softwood. I'm trying to address the power issue, but I doubt if even a strong 066 will have "enough" power at my elevation.

I can't tell you how jealous I am of those guys having "problems" with their 3120 hitting the rev limiter while milling big wood. :bang:



> The loss of time from dealing with broken chains might actually make it slower to mill with


You are right that I didn't address the strength issue, because I haven't gotten that far yet.

My only experience running lo-pro is on a 33cc Homelite. Rest assured that it does not have the power to break chains. 

I might let the first broken chain slide, because as you say, it may take a while to learn to be gentle with the throttle, plus chain life should get better after the sprocket is broken in. If chains continue to break on a regular basis, forget it.

I appreciate hearing about your experience with broken lo-pro. That's the kind of honest data we need. I'm not sure what you mean by "cheap" chain ? I buy my chain from Baileys which means Carlton or Oregon.

BobL, your 441 probably makes as much power at sea level as my 066 makes at my elevation.


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## SilverBox

mtngun said:


> I appreciate hearing about your experience with broken lo-pro. That's the kind of honest data we need. I'm not sure what you mean by "cheap" chain ? I buy my chain from Baileys which means Carlton or Oregon.



The worst lopro I've ever used was "Powercare" from the big orange box store. It snaps after 1/4 to 1/2 of the teeth are filed down on 2 horse saws and you never get to file it at all on 3 horse saws, it snaps before it gets dull for the first time. Weakest lopro I've ever seen. I've seen Oregon break once or twice on 3+ horse saws when the teeth were just about filed away. I've worn out 20-30 chains of lopro on smaller saws. 

I've never used lopro for milling, but like you MTN, I've considered it a few times. I have a bunch of larger oak that I'm considering cutting down into 1" slabs, just the wood savings of the smaller kerf would get me 2-3 extra boards per log.

In the past peeps who have used lopro to mill with on bigger saws have posted that they occasionally break chains, but I don't remember them being all that specific about the frequency of breakage. 

Another thought is to start out with relatively high rakers to avoid breakage then if that goes well lower them down as you go. If you take smaller bites you should put less stress on the chain.


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## BIG JAKE

The low pro is .365 pitch while 3/8's is .375 right? So that pitch difference would be cumulative around the sprocket I suppose. On a worn 3/8's sprocket it might work better, but the strength issues may not be worth it-no firsthand experience here. The big problem is the side plate difference as viewed in the pics(great pics by the way). I'm honestly surprised they haven't come up with a beefy lo pro or totally new thin kerf chain yet for milling. Grande Dog buys enough chain from the manufacturers maybe they'd listen to him or at least consider engineering such an animal. Doesn't seem like a big problem to slap on some bigger plates or a better alloyed higher strength lo pro plate that could take the extra hp-I'm not exactly sure what the differences are other than the pitch and the obvious side plate differences. I'd think there are enough people milling out there it'd be worth their while to come up with a thinner kerf milling chain-anything would help. I'd buy it, because the smaller bite would equate to more available hp for higher chainspeeds in the cut, and more lumber at the end of the day. The question is, how much more lumber? Maybe it's not enough to write home about. Could bars running .050 guage be made narrower also and tempered to a higher hardness point? Sure they could but you'd need thinner, stronger plates to ride on that narrower bar also. No expert here just throwing some ideas out there. The engineers must have considered this at some point though. Maybe it's as simple as not enough monetary returns for the effort, or some other real/insurmountable engineering type issue. What would you pay for such a set-up? A third more/double the cost?


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## mtngun

SilverBox said:


> Another thought is to start out with relatively high rakers to avoid breakage then if that goes well lower them down as you go. If you take smaller bites you should put less stress on the chain.


+1. Lo pro is about rpms, not big chips. I'm hoping to gain 1000 rpm in the cut -- that would be a 10% improvement. 

I ordered the goodies tonight (along with a mini mill and rings for the pop-up piston project), and I'll post the results so we'll all learn from the experiment whether it is a flop or a success.

I went with a Stihl sprocket nose bar because I got a good price on the 'bay and my limited experience with hard nose has me afraid they cause a lot of drag. However, BobL doesn't mind hard nose, so maybe I just didn't have the tension and lubrication right.


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## Kicker_92

What gauge bar are you using? I was looking at switching to low-pro on the 385xp, but didn't see any listed in 0.058" gauge.

I'm switching our 56cc poulan to low-pro, it has a 0.050" gauge bar so baileys carries the chain. Will hopefully work nice for resawing the cants we've been making.


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## BobL

Kicker_92 said:


> What gauge bar are you using? I was looking at switching to low-pro on the 385xp, but didn't see any listed in 0.058" gauge.
> 
> I'm switching our 56cc poulan to low-pro, it has a 0.050" gauge bar so baileys carries the chain. Will hopefully work nice for resawing the cants we've been making.



As far as I know, lo pro is only 050.


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## Rooshooter

mtngun said:


> Because I've started to lay out some money to convert my 36" mill to lo-pro, I'm going over the subject with a fine tooth comb. I'm planning to run the Carlton/Oregon stuff, so my investigation only concerns Carlton/Oregon and not the Stihl/Logosol picco. Here's what I've found and some of this will be old news, so bear with me.
> 
> Since Carlton makes lo-pro ripping chain, I contacted Carlton and asked if I could run their lo-pro on my "regular" 3/8 bars and sprockets. Carlton has yet to reply.



Not really 3/8LP is actually .365" pitch and as you have already found out is does not fit the std 3/8 nose sprocket.



mtngun said:


> One of our members, Matilda's Mate, once posted that a Carlton rep gave him the green light to run Carlton lo-pro on "regular" 3/8 bars and sprockets. While I believe Matilda's Mate, I suspect that Carlton's lawyers will frown on putting that advice in writing, for liability reasons.



Just goes to show that the Australian agent does not know much about the product they sell.



mtngun said:


> I also contacted Oregon, and they do not "_advise_" running lo-pro 3/8 on "regular" 3/8 sprockets and bars.[?QUOTE]
> 
> At first, Oregon flat out said that the two types of chain were not "_compatible_."
> 
> I asked if they could recommend a lo-pro rim sprocket that fits a Stihl 066. No, they don't make such a sprocket and they "_advise_" against using a regular 3/8 rim sprocket "_as the drive link will not seat down into the sprocket correctly_."



This is somewhat correct, there is not much difference on the drive sprocket and a 3/8 std rim can actually be used,The rim sprocket does wear a little faster than normal, However I have been using one for two years running the 3/8LP chain on a 3/8LP sprocket nose bar without any detrimental effects, I would not run a 3/8LP chain on the 3/8 std nose sprocket though, this is asking for trouble.



mtngun said:


> Oregon also advised against running lo-pro on a "regular" 3/8 nose sprocket, because "_there is increased risk of the chain jumping off the bar when using the incorrect chain_."



This is correct.  





mtngun said:


> So..... I concede that the fit of lo-pro on a "regular" 3/8 nose sprocket is seriously flawed, and it will probably increase chain stretch.
> 
> I'm_* guessing*_ that if you ran lo-pro on the sprocket long enough, the sprocket teeth would eventually "wear in" to fit the lo-pro decently.



More likely you would get chain failure ( breakage ) before this happened.

Check the attached pics, there is quite a bit of difference between the 3/8LP &3/8 std noses, When you check the drive links on 3/8 Std Carlton & 3/8LP Carlton there appears to be no difference in the profile of the link. 



For information, I have managed to aquire several Stihl mount (380,440,460 Etc ) 25" GB Pro Top sprocket bars that are specifically made for 3/8LP, I think this is the last of these, Any of the Oz cs millers can contact me if you require one.

Laurie
AKA Sawchain


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## SWE#Kipp

I have a friends that run Stihl picco 3/8 on the logosol chainsawmills with 660 saws and large electrical motors and there seems to no problems witn breaking but that is with running bars up to 28" .


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## ray benson

A 100' reel of 3/8 chain is 1640 drive links.
A 100' reel of 3/8 low pro is also 1640 drive links
They are the same pitch. I believe Bailey's calls low pro .365 to help differentiate between it and regular 3/8 chain.
http://www.baileysonline.com/itemdetail.asp?item=WP100+30LR&catID=876
http://www.baileysonline.com/itemdetail.asp?item=WP100+30RCS&catID=838


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## Philbert

Good Photos. Thanks.


Rooshooter said:


> 375x050 Pro Top w.365LPx50 Carlton1
> 
> 
> 
> 
> 375x050 Pro Top w.365LPx50 Carlton2
> 
> 
> 
> 
> 38LPx050 Pro Top w.365LPx050 Carlton1
> 
> 
> 
> 
> 38LPx050 Pro Top w.365LPx050 Carlton2
> 
> 
> 
> 
> 38LP Carlton on 38 LP GB bar1


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## mtngun

Rooshooter said:


> I would not run a 3/8LP chain on the 3/8 std nose sprocket though, this is asking for trouble.


Thanks for sharing your experience, Rooshooter. 

As both your excellent pictures and mine clearly show, a 3/8 nose sprocket does not correctly support the drive link of lo-pro. Instead, the tip of the sprocket wedges in between the links. This is a bad thing ...... but nonetheless, people are doing it, and the sky has not fallen.

The saving grace is that the loads on the nose sprocket are not huge, providing you don't overtighten the chain. The nose sprocket is merely an idler.

I'm wondering what would happen if I ground off the tips of the nose sprocket teeth ? :monkey:

Obviously, the ideal solution would be to make lo-pro nose sprockets readily available for milling bars. Perhaps if it is proven that lo-pro is viable and desirable for big milling saws, Baileys could commission a run of lo-pro nose sprockets for their Woodland Pro bars. 

Kicker92, Husky seems to favor 0.058" gage so you may be out of luck. Perhaps Baileys has enough clout to commission a run of 0.050" Husky bars if the demand is there ? Meanwhile, is it possible to adapt a Stihl bar to a Husky ? 

I'd suggest waiting for my field results before you spend a lot of money. Let's see how lo-pro holds up on longer bars, and get more speed data.


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## verticaltrx

As I stated in my other thread, I've been running Stihl Picco 3/8 chain on my 361 (20" bar) and small log mill for a while now. From what I have read, the Sthil Picco chain is supposed to have even more fitment issues than the other brands of low-pro chain. 

The chain did ride a little higher on the nose sprocket, and felt a little odd when you ran it around the bar by hand at first. It was fairly smooth, but you could tell it didn't fit the nose sprocket just right. Once it stretched a little and things wore in a bit its running great. I don't know what the long term effects of this will be, so I may keep a "worn in" bar and rim sprocket just to run this chain. 

I've milled a few hundred bd ft of pine with these chains and no breakage or thrown chains yet. The difference in cutting speed was very noticeable over standard 33RSC chain. I run with a 30* top plate angle, from what I gather this makes for a little faster, but less smooth cut. 

When I upgrade to a larger mill/saw, I'll definitely run low-pro chain if at all possible.


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## Rooshooter

mtngun said:


> Thanks for sharing your experience, Rooshooter.
> 
> As both your excellent pictures and mine clearly show, a 3/8 nose sprocket does not correctly support the drive link of lo-pro. Instead, the tip of the sprocket wedges in between the links. This is a bad thing ...... but nonetheless, people are doing it, and the sky has not fallen.
> 
> The saving grace is that the loads on the nose sprocket are not huge, providing you don't overtighten the chain. The nose sprocket is merely an idler.
> 
> I'm wondering what would happen if I ground off the tips of the nose sprocket teeth ? :monkey:
> 
> Obviously, the ideal solution would be to make lo-pro nose sprockets readily available for milling bars. Perhaps if it is proven that lo-pro is viable and desirable for big milling saws, Baileys could commission a run of lo-pro nose sprockets for their Woodland Pro bars.
> 
> Kicker92, Husky seems to favor 0.058" gage so you may be out of luck. Perhaps Baileys has enough clout to commission a run of 0.050" Husky bars if the demand is there ? Meanwhile, is it possible to adapt a Stihl bar to a Husky ?
> 
> I'd suggest waiting for my field results before you spend a lot of money. Let's see how lo-pro holds up on longer bars, and get more speed data.



Hey mtngun

There is a bit of a problem with grinding the sprocket teeth down, You have to remember that the 3/8 LP is actually .365" pitch whereas the 3/8 Std is .375" pitch, the photo's we both posted clearly show the slight misalignment of the drive links in the std sprocket which would cause an increase in chain stretch.


Yes it is possible to adapt a Stihl bar to husky by using 12mm to 9mm adaptor.

*I also have a bunch of roller nose 25" titanium bars with the Husky mount available ( about 30 of them ), thicknes is .182"*

I run various non standard bars on my 880's and 660 by use of adaptors, extending and or lengthening bar slots, re drilling oilers and adjuster holes.
As long as the bars are not the titanium alloy there is no problem drilling them, I do use tungsten bits if I have to re drill titanium though.


As far as manufacturing noses for standard bars there could be a problem as the bars designed for 3/8LP are thinner material, I have measured regular GB Pro Top bars at a thickness of .192" whereas the Pro Top manufactured by GB for 3/8LP is .163", the problem arises when the chain is filed back past a certain point and the chain becomes just slightly wider than the bar thickness due to tapering of the cutter, it doesn't cut very well when you have not much cutter left, however this is not a major problem.
I have tried 3/8LP on std hard and sprocket nose bars and have encountered a slight problem. I have also thrown chains when using 3/8LP on a 3/8 std sprocket nose bar.


The problem with manufacturers not wanting to use 3/8LP on longer bars is that the drive link being only .050" is likely to fail ( at the rivet hole ) with increased load on the chain, The drive link being the weakest part of the chain.
I would suggest using a skip chain or extended skip to reduce load on the chain if using longer bars.



I am in regular contact with Tom Beerens of GB ( Griffiths & Beerens ) so I will ask the question about a run of 3/8LP bars in 30 - 36", I would imagine a deposit would be required before manufacturing the goods though.


As you are aware I deal in chainsaw accessories - Not chainsaws, and actually get out and cut big timber and run a GB66" DE mill, whatever I comment about I have done or tested myself. I do not bullsh*t about it like another dealer over here.

I am currently testing the new chain for GB and reporting back to Tom Beerens, some problems at first however last batch of 404 I tested is good, I do have a little input on modifications etc, and have requested samples of special skip chain to my specs for testing. More on this when I get it and test it. 
I have even had Tom out with me one full day using my 880 to see what the real world is like. ( Cutting Ironbark no less  ) Think he was a bit sore at the end of the day, though he does adopt the hands on approach which is good for the company director come engineer to do.

I also did initial pre release testing on the German made Carlton bars, however I don't think they took much notice of the report, the bars were crap.


There are some photo attachments, 2 are a little off the track, but show bar mods.
There are 2 of a 25" Titanium roller nose bar ( nose radius ground a little )with 3/8 LP sitting on it, this bar is .182" thick so will handle the 3/8LP chain better.
Pic 5 show Tom Beerens on the end of one of my 880's cutting up some of my Ironbark firewood logs.

Hope this helps a little.

Laurie


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## mtngun

Rooshooter said:


> You have to remember that the 3/8 LP is actually .365" pitch whereas the 3/8 Std is .375" pitch


That seems to be in dispute. I don't claim to know for sure except, as someone pointed out, there are 1640 links in a 100 foot roll for both types of chain. That's roughly 0.365" pitch. 



> I have measured regular GB Pro Top bars at a thickness of .192" whereas the Pro Top manufactured by GB for 3/8LP is .163", the problem arises when the chain is filed back past a certain point and the chain becomes just slightly wider than the bar thickness due to tapering of the cutter, it doesn't cut very well when you have not much cutter left, however this is not a major problem.


Thanks for the insight, I hadn't thought of that issue.



> I have also thrown chains when using 3/8LP on a 3/8 std sprocket nose bar.


Thanks for that data point. 



> The problem with manufacturers not wanting to use 3/8LP on longer bars is that the drive link being only .050" is likely to fail ( at the rivet hole ) with increased load on the chain


 Agreed. A broken chain could result in an injury (though less likely with a conventional Alaskan mill where the bar clamps double as chain catchers) and the manufacturers don't want to get sued.

Still, Carlton does sell lo-pro ripping chain, and who in the heck mills with a 40cc saw ? Carlton surely understands their lo-pro ripping chain is being used primarily on larger saws. They are winking at the practice, even though they won't officially condone it. 



> I am in regular contact with Tom Beerens of GB ( Griffiths & Beerens ) so I will ask the question about a run of 3/8LP bars in 30 - 36", I would imagine a deposit would be required before manufacturing the goods though.


 Yes, and as of today there would not be a large market. 

So far what we are seeing on this forum is a trend toward lo-pro at least on moderate length bars, and I suspect that trend will continue. But, it may take years and there will be problems along the way. At some point we will reach limits on bar length and power where we have to draw a line in the sand.



> whatever I comment about I have done or tested myself. I do not bullsh*t about it like another dealer over here.


 Then you and I will get along fine. 

I like your roller nose bar, that would be ideal for the CSM'er who wants the option to use either regular or lo-pro 3/8.



> Hope this helps a little.


Real world data always helps.


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## mtngun

verticaltrx said:


> As I stated in my other thread, I've been running Stihl Picco 3/8 chain on my 361 (20" bar) and small log mill for a while now. .......I've milled a few hundred bd ft of pine with these chains and no breakage or thrown chains yet. The difference in cutting speed was very noticeable over standard 33RSC chain.


Thanks for the data. Yours is another data point suggesting that a smaller kerf is good for milling. 

I'm deliberately ignoring the Picco issue in this thread because 1) I would rather stick with Oregon/Carlton brands from Baileys due to cost and convenience and 2) the lo-pro fitment question is confusing enough without throwing Picco into the mix.



> When I upgrade to a larger mill/saw, I'll definitely run low-pro chain if at all possible.


You and me and everyone else, is the trend we are seeing on this forum.

It may take a while for us to sort out the lo-pro milling technology, though.


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## Rooshooter

mtngun said:


> That seems to be in dispute. I don't claim to know for sure except, as someone pointed out, there are 1640 links in a 100 foot roll for both types of chain. That's roughly 0.365" pitch.



Thanks for the comments mtngun.
It may be a point of dispute, However the Oregon importer also told me 3/8LP is actually .365" 
For those that doubt it hang several feet of both 3/8LP & a 3/8 std chain both on the same nail and see which chain is longer for the same amount of drive links - not much in it but the 3/8 std is longer.
In Carlton chain both 3/8 LP & 3/8 std are 1632 links per 100' roll.

Laurie


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## mtngun

*The five minute fix ? ? ?*

Ground 3 teeth on my see-through nose sprocket. The teeth were simply ground flush with the nose. I left the remaining teeth as-is for comparison and for future experiments.

Now the drive links are supported fairly well. :rockn: :rockn: :rockn: :rockn: :rockn: Perfect ? No, but bear in mind this is a well worn sprocket. At least now the sprocket tooth is not trying to wedge the links apart like the OEM tooth.






View from the other side.





The grinding process leaves burrs on the teeth, and there is no way to deburr them, so the burrs cause the sprocket to bind at first. The burrs will wear off quickly, though.

I'm feeling pretty good about this mod  , but will reserve judgment until it has been field tested.


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## mtngun

Back to the pitch dispute........

I'm not sure that it matters -- yes, the pitch needs to be compatible with the sprockets -- but sprocket fit is also effected by the height of the side lengths and the shape of the drive lengths. And, the effective pitch will change over the life of a chain, as the chain stretches.

Nonetheless, I used a digital caliper to measure chain pitch. I measured center-of-rivit to center-of-rivit across 16 links, because that's as far as my 6" calipers would span. 

A new Oregon lo-pro was 0.366", as best I could measure.

A new Carlton "regular" 3/8 was 0.367", as best I could measure.


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## Rooshooter

mtngun said:


> Back to the pitch dispute........
> 
> I'm not sure that it matters



Thanks mtngun, I'm not really worried whether it matters, I am merely pointing out facts. I've had my input on this discussion and that's abt all I have to say.

:deadhorse:


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## Andrew96

mtngun said:


> The five minute fix



Well you had me thinking about the pitch vs. sprocket issue in the shop all day (remembering your photos). Through various drive systems that I've worked on, a pitch that close for an idler (that's all the nose sprocket is anyway) is close enough. The side plates however are an issue. As you know..you cannot have the chain riding up on that side plate like your earlier photos (low pro on standard nose sprocket) as the whole load will be point loaded on the side plate and will wear wrong and I bet...weaken it over time and cause a failure. The only thing I could think of was to mill the sprocket down to fit the low side plates. You'd have a dedicated low pro bar though. 
Today...I see you've already done that...although with a burr...which I feel (as you) will wear off in a 2 minute warm up. 
I think your setup is a safe go....good for you for sorting it out. I'm excited to hear about the performance. I'm going to try to figure out how to send you one of those reward thingys.


----------



## mtngun

Andrew96 said:


> You'd have a dedicated low pro bar though.


My new 0.050" bar will be dedicated to lo-pro. However, I can't think of any reason the modded sprocket wouldn't work with regular 3/8.

I am not aware of any lo-pro nose sprockets for milling bars other than the few that Rooshooter has for GB bars. However, I did not do an exhaustive search. My goal was to use economical, readily available components. 

I assume Stihl picco nose sprockets would not fit Oregon/Carlton lo-pro, but don't know that for a fact ?

I'd like to run out and field test lo-pro today, but it may be weeks before everything is assembled and then I'll have to wait for a break in the weather.


----------



## huskyhank

How about a roller nose instead of a sprocket?


----------



## DRB

huskyhank said:


> How about a roller nose instead of a sprocket?



Ya I was wondering about that to. Have not had time to look into it though.


----------



## mtngun

huskyhank said:


> How about a roller nose instead of a sprocket?


Like the one in Rooshooter's pic. 

Not too common in the states, though.


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## Philbert

Did not know what the inside of a roller nose bar looked like.

So there are 2 discs that support/rotate the links without engaging the drive link tangs like a sprocket?

I get that this would work with any pitch chain. Does this extra thickness at the nose get hung up in the cut?

Philbert


----------



## mtngun

Philbert said:


> Does this extra thickness at the nose get hung up in the cut?


That would be my guess as to why the roller nose fell out of favor. Wouldn't be an issue for an Alaskan mill, though.


----------



## BobL

I use a GB roller on my 60" GB bar.
I also use a GB roller nose on my 404 60" Stihl bar with my home made adapter plate.
Adapter made from Hardened steel plate from a circular saw on left, mild steel prototype on right.


----------



## Philbert

So, aside from the exposed fasteners you used, would/does the roller end part ever get hung up in a kerf?

Philbert


----------



## BobL

Philbert said:


> S, aside from the exposed fasteners you used, would/does the roller end part ever get hung up in a kerf?
> 
> Philbert



While the raised roller part does look significantly thicker than the bar part, the roller nose thickness away from the raised roller itself is 6.05 mm while on the raised roller section is 6.35 mm so about 0.3 mm or 0.012"

I have not used a roller nose bar on a conventional saw but I believe they are fine with 404 chain. For 3/8 they are also OK when the chain is new and it's only once the cutters are more than about 1/2 gone that it can become a slight issue.


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## mtngun

*Carlin's statement*

Finally heard back from Carlin. Remember as you read this that Carlin sells lo-pro ripping chain.



> I contacted our engineering dept and they advised against running 3/8 LP on a 3/8 sprocket. 3/8 LP is actually .365 while the 3/8 is .375 so there is a dimensional difference which could cause the chain to fail prematurely causing injury or death to the operator.



20 years from now, AS members will still be debating whether 3/8 is 0.375 or 0.365. :monkey:

I replied to Carlin with pictures showing how lo-pro fits on a rim sprocket and on my modified sprocket. I don't expect them to change their tune, though. Their statements are obviously being vetted by lawyers.

I expect to have my lo-pro bar running later this week.


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## mtngun

Virgin Stihl 0.050" 36" bar, sprocket teeth ground down, shown with Woodland Pro Lo-Pro milling chain.





I tried to measure the kerf width of the lo-pro milling chain, but it's easier said than done. Here are my measurements, but remember the kerf measurement is not very accurate:

Woodland Pro lo-pro milling chain -- 0.253" kerf

Woodland Pro 0.063" 3/8 milling chain -- 0.312" kerf

Stihl 36" x 0.050" ES bar -- 0.190" thick

The lo-pro kerf is approximately 20% thinner than regular 3/8 chain.

The lo-pro kerf is wide enough to provide clearance for the Stihl bar, but there isn't a lot of wiggle room.

That's as far as I got tonight.


----------



## DRB

Mtngun keep up the good research

I want to setup my 356 husky with some sort of thinner kerf set up for ripping boards from cants.


----------



## Kicker_92

Do you predict that a 20% smaller kerf will correlate to a 20% decrease in cut time?

What is the angle on the milling chains? Also, do you have a way of measuring the width of the cutters? (for what they would cut at near a 0° file angle)


----------



## mtngun

Kicker_92 said:


> Do you predict that a 20% smaller kerf will correlate to a 20% decrease in cut time ?


I hope to do some timed cuts on a cant later this week, comparing the speed to 3/8". Meanwhile, didn't someone else post lo-pro speed tests a long time ago -- it might have been Aggiewoodbutcher ?



> What is the angle on the milling chains?


10 degrees



> Also, do you have a way of measuring the width of the cutters? (for what they would cut at near a 0° file angle)


I'm not sure what you mean by "width of cutter" as opposed to width of kerf, but I'll try to post a close-up pic of the cutter tonight. 

It is a dainty chain, no doubt about it. I wouldn't recommend it on your 880. It remains to be seen if it'll hold up on my 066.


----------



## Kicker_92

mtngun said:


> I'm not sure what you mean by "width of cutter" as opposed to width of kerf, but I'll try to post a close-up pic of the cutter tonight.
> 
> It is a dainty chain, no doubt about it. I wouldn't recommend it on your 880. It remains to be seen if it'll hold up on my 066.



I'm thinking more for the 385xp. I will be switching my Poulan 56cc to lo-pro soon, but still debating on the 385xp if it's too much grunt.

By width I meant the distance to the edge of the cutter from the centerline of the chain. So in theory, if the cutter was filed near 0°, it would make a cut that is the width of the chain.


----------



## mtngun

Kicker_92 said:


> By width I meant the distance to the edge of the cutter from the centerline of the chain. So in theory, if the cutter was filed near 0°, it would make a cut that is the width of the chain.


That's kinda what I meant by "keft width", but it's difficult to measure. I've measured it several times using several different methods and get different results each time.

I just did it again using what I think is the best method so far -- I laid a loop of chain on a bar, zig-zagged the loop back and forth across the bar 4 times, laid another bar on top of that, and then measured the entire "sandwich". Subtracting the combined thickness of the two bars yields the theoretical kerf width.

LP ripping = 0.223" keff

3/8 x 0.063 ripping = 0.265" kerf

LP kerf is 15.8% thinner....... on _*that*_ round of measurements. 

On a power-limited CSM, like my lame 066, I suspect the smaller kerf will translate into faster cutting speed. Not so on BobL's 880 that drives an 8 pin 9500-10,000 rpm with aggressive rakers to boot.


----------



## SilverBox

I think your first numbers were closer, when i cut with lo pro I get around 1/4 inch kerf and with I cut with regular .375 I get around 3/8 inch kerf. My rough guess estimate was 33% savings before you posted your numbers. 

See how it does in the wood and measure that.


----------



## BobL

Don't forget that actual kerf is also slightly dependent on top plate filing angle.


----------



## mtngun

BobL said:


> Don't forget that actual kerf is also slightly dependent on top plate filing angle.


How is that ? I presume the chain is going to wiggle side to side in the cut and the kerf will end up being wider than the chain ? 

Anyway, as promised, here is a pic showing the lo-pro cutters. This 3/8 chain has a few miles on it while the lo-pro is new. Note that the cutters on Bailey's 3/8" ripping chain seem to be a little narrower than the typical cross-cut chain.


----------



## BobL

mtngun said:


> How is that ? I presume the chain is going to wiggle side to side in the cut and the kerf will end up being wider than the chain ?



That's right. The top plate filing angles force the cutter sideways a little. It's most noticeable going from a 35º to a 5º top plate filing angle.

For cross cutting this slightly wider kerf is produced by the side plate angle. It also varies depending on the type of wood. Wood with tough fibers is more likely to show this up.


----------



## mtngun

Time to generate some hard data ........

A 12.5" ponderosa pine cant, 95" long. I would rather have a cant that is more representative of the wood I typically mill -- doug fir in the 16" - 24" size, however, the logging roads are not fit to travel at the moment, so I had to make do with this pine log that I had at home.





The CSM now has a stopwatch for timing cuts.





First up, Woodsman Pro 0.063" x 3/8" ripping chain, brand spanking new.

*ON YOUR MARK, SET, GO ! ! ! *





After cutting two boards, the 0.063" chain had stretched and would have needed to be tightened. This is typical behavior for Woodsman Pro chain -- it stretches a lot when it is new, but after snugging it up once or twice, then it settles down and behaves.





Continued in the next post ...........


----------



## mtngun

Now here comes the Woodland Pro lo-pro ripping chain, again brand spanking new. The Stihl bar was also new and the chain was a tight fit in the bar, with noticeable drag. A new rim sprocket was used, too. Break-in consisted of running the chain at part throttle for a couple of minutes before beginning the cut.

After cutting two boards, the lo-pro had stretched and needed to be tightened. 





5 boards plus an odd sized leftover. The boards have nice character, but they are too punky and have too many checks to be suitable for furniture. I think I'll use them for closet shelving. The odd sized leftover will even get used as a backer for "no trespassing" signs. The saw dust will get used to clean up oil spills in the shop. I don't like to waste natural resources.





I suppose you want to know the results ?

With the 3/8" chain, the saw was running in its powerband, at 8500 - 9500 rpm. Even if I pushed it hard, it wouldn't drop below 8500. Compare that to my last trip to the woods where the saw was struggling to maintain 8500 in a doug fir and would bog unless fed oh-so-slowly. 

In other words, the 12.5" pine cant was not much of a challenge for the saw, and that's a problem for this test, because lo-pro shines in situations where the saw is underpowered with 3/8 chain. Oh, well.

With the lo-pro chain, the saw started out running 10,000 - 10,500 rpm. Cool, that's exactly the rpm I had hoped to attain with lo-pro chain.  However, by the second cut the rpms had dropped, and by the 3rd cut it would only hold 9200 with a modest push. Either the chain had dulled quickly, or else the saw was getting tired (or hot). I didn't let it cool off between passes except for the few minutes it took to get set up for the next pass.

For each cut, I paused a single time to install one wedge, which took 2 - 5 seconds depending on how many times I dropped the wedge. 

The 3/8" x 0.063" times were 151 seconds and 146 seconds in that order. Average = 148.5 or 0.64 inches per second.

The lo-pro times were 137, 139, and 137 in that order. Average = 137.7 or 0.69 inches per second.

Note that both the first and the last lo-pro cuts were 137 seconds, even though it had lost 1000 rpms. How is that, you ask ? Because on the first pass, I did not have a good feel for the optimal feed rate. Practice makes perfect. 

Ditto for the 0.063" chain, where the 2nd pass was faster than the first.

The lo-pro cutting speed was 7.8% faster than the 0.063" chain, on average. 

I was expecting at least 10% faster, so I'm a little disappointed. However, something happened to slow the speed down quite a bit part way through the lo-pro test -- it could have been the saw, it could have been the chain dulled quickly, it could have been knots (the lo-pro boards did have more and bigger knots), it could have been ice (the log had been sitting out in the weather for 2 years and parts of it was wet and frozen). And so forth. 

However, for all its imperfections, this is as fair a speed comparison as I'll ever be able to do, so I have to accept the results. :agree2:

The next step in this saga is just to continue running the lo-pro and see how it holds up. Will it continue to stretch or will it stabilize? Will it continue to dull quickly? Will it's speed advantage be more pronounced in bigger wood?


----------



## BobL

Good work mtngun - it has saved us all a lot of comparative work.

What were the raker depths? The Baileys ripping chain looks like it has seen some use so the real question is were the cutting angles the same?

I also didn't think there would be much difference in cutting speed. Another disadvantage of lo-pro is that it cannot carry as much sawdust although that wouldn't be significant in these cuts.


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## mtngun

Bob, brand new chains were installed at the start of the speed test, so they still had the factory angles, factory rakers, and factory sharpness (or lack thereof -- it is not unusual to see glint on the cutters, but they cut OK nevertheless). 

Factory spec is 0.022" rakers, 10 degree top plate, 60 degree cutting angle, and 10 degree tilt. Same for both chains.


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## BobL

mtngun said:


> Bob, brand new chains were installed at the start of the speed test, so they still had the factory angles, factory rakers, and factory sharpness (or lack thereof -- it is not unusual to see glint on the cutters, but they cut OK nevertheless).
> 
> Factory spec is 0.022" rakers, 10 degree top plate, 60 degree cutting angle, and 10 degree tilt. Same for both chains.




The reason I asked wasa because I saw this picture you posted and the standard chain has shorter cutters.


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## mtngun

I used the older chain in that picture to make the slabbing cut while preparing the cant. Then I switched to a brand new chain so I would be comparing apples to apples in the speed test.

The older chain may have 12 degree or 15 degree cutters. It definitely has a more aggressive raker. That dates back from my experiments with different cutter angles and the FOP rakers.


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## mtngun

I posted this info on the chainsaw forum, but will add it here, too.

In the interest of science, knowledge, and truth, I cut off one side of a 3/8 rim sprocket so we could visually inspect how the drive links fit on the sprocket teeth.

The rim is a moderately well used Oregon 3/8-7. Made of hardened tool steel, it was tough to cut, however, no effort was spared for the benefit of my good friends on AS. 

Showing new 3/8 Oregon chain. Since I have no way to apply torque, the drive links are not necessarily pulled tight against the sprocket teeth, however, you can see that if it were pulled tight, it would fit fairly well.





Showing new Oregon lo-pro. Only 2 drive links make positive contact with the sprocket teeth. The other drive links overshoot the teeth. Even though lo-pro has the same pitch as 3/8, a slightly larger rim diameter would be necessary to compensate for lo-pro's narrower side links (a picco rim does have a larger diameter, but I suspect it would be too large for lo-pro).





Showing used Carlton lo-pro. Again, only 2 drive links make positive contact while the others overshoot the sprocket teeth.





Well, I hate to admit it, but Saw Troll was half right.  The difference in the height of the side links does affect the way lo-pro fits a rim sprocket (dunno about how lo-pro fits on a 3/8 SPUR sprocket). The drive forces will be carried by only 2 drive links instead of the usual 3. That's more stress per tooth.

That said, it's not the end of the world. People have done it, are doing it, and will continue to do it until lo-pro rim sprockets are made available.


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## Philbert

Nice applied research. Tried to rep you for it, but the rep gods . . .

Philbert


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## DRB

Nice investigative reporting. 

Keep us updated as your quest continues.


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## BobL

Now that you have cut the sprockets here's a very interesting experiment to try.

Put the sprockets and chains back onto the CS with the exposed sides facing out and apply a normal chain tension.
Take a photo of the drive sprocket and chain, and use a feeler gauge to measure the gaps between ALL the drive links and sprocket teeth. I suspect a moderately normal worn 3/8 chain on moderately worn 3/8 sprocket is not going to come up roses on this test.

You can then repeat the test with a higher tension.

My hypothesis is once a drive link is off the sprocket tooth it's off and a half sprocket of chain is driven once around the sprocket by one tooth only. If this is the case then provided the lo pro doesn't stretch to the point where it jumps a tooth, it is no different to any other 3/8 chain. Remember the forces generated are not that much different to the back force generated on a chain when only one cutter cuts wood which is pretty common in narrow wood. 

According to chain and sprocket theory [http://chain-guide.com/basics/2-1-2-engagement-with-sprockets.html] a chain being driven by a sprocket with less than 60 teeth can only stretch 1.5% before it reaches a point where it is largely driven by one one drive link and one tooth on that sprocket.

A chain on a 20" bar (nominally 40" long) can therefore only stretch 0.6" before it becomes driven by one drive link and one sprocket tooth. This translates to the bar needing to be elongated by 0.3". 

In the case of a 60" bar this 0.9" of bar movement.

So I wonder if this is the case for just about all chains?


----------



## mtngun

BobL said:


> Put the sprockets and chains back onto the CS with the exposed sides facing out and apply a normal chain tension.
> Take a photo of the drive sprocket and chain, and use a feeler gauge to measure the gaps between ALL the drive links and sprocket teeth.


That's a good idea, though a standard feeler gauge will be too wide to fit in that little space.

Since I still regard lo-pro as an experiment, I'm OK with using the 3/8 rims for now. If I decide to stick with lo-pro, then I'd get more serious about the drive sprocket.

Wondering out loud :

-- how would lo-pro fit on a 3/8 spur sprocket ?

-- I think a picco sprocket's diameter is too large for lo-pro, but what if I turned it down on a lathe ?


----------



## huskyhank

Further in BobL's post:

http://chain-guide.com/basics/2-2-1-chordal-action.html

I think that as a chain and its sprockets wear in together they mate better than when new. Mismatches in wear between a sprocket and a chain might be similar to what you're getting with your mixed up parts -- i.e. new chain on a worn out sprocket.


----------



## Rob D

Just have to say a great thread and I'd like to stick my neck out a little and add my pennys worth - 

Just a few things I've found which are far more rule of thumb:

Low pro chain can break on larger saws (already said I know)

IMO low pro chain seems to me to dull faster when cutting larger trees that have more grit etc in them.

If indeed I'm right and it dulls faster = more sharpening time then there would be less point in kitting a saw out with lo pro in order to save time.

If low pro 3/8 chain is being substituted for .404 chain then there will be more cutters on the same length chain which I have found leads to more drag (albeit a smoother cut) and doesn't give the same chip clearance rate. I have not measured this - it is more just the feel of it.

If using low pro to reduce saw kerf it does beg the question if kerf is an issue (as the timber is valuable) then it is probably worth using/hiring in a bandsaw. If accesss is difficult then break down with a CSM first with standard ripping chain then use a bandsaw.



So in relation to the above does switching over to a low pro system really warrant the effort anyway? As the first post says there seems to be no clear consensus on using low pro chain - that says a lot in itself!


----------



## mtngun

Rob D said:


> IMO low pro chain seems to me to dull faster when cutting larger trees that have more grit etc in them.
> 
> If indeed I'm right and it dulls faster = more sharpening time then there would be less point in kitting a saw out with lo pro in order to save time.


I, too, am concerned about it dulling faster. I need more field experience with lo-pro before I can draw any conclusions.



> If low pro 3/8 chain is being substituted for .404 chain


 Who uses 404 for milling ?



> If using low pro to reduce saw kerf it does beg the question if kerf is an issue (as the timber is valuable) then it is probably worth using/hiring in a bandsaw.


It's about kerf to the extent that kerf width influences cutting speed.

Bandsaws are great if you own timber, but they are not an option on public land in the US.


----------



## Kicker_92

Rob D said:


> IMO low pro chain seems to me to dull faster when cutting larger trees that have more grit etc in them.



It's the leading edge of the cutter that is critical, and that is about the same size whether it's lo-pro or not. I've got some 16" lo-pro loops to try out, but they are semi-chisel, and I'd be comparing to full-chisel chain for wear, so not apples to apples.


----------



## Rob D

Who uses 404 for milling ?

.404 is my main chain for milling.

Personally I have found it to be the fastest over a number of cuts in that it seems to retain the best stay sharp quality. And I find I mill quick with it.

I know the leading edge (or corner) is the critical thing with a chainsaw chain and this will be the same size low pro or not...... but I just find that .404 chain keeps cutting better for longer.

I may not be right this is just my own experience


----------



## BobL

Rob D said:


> Just have to say a great thread and I'd like to stick my neck out a little and add my pennys worth -
> SNIP
> So in relation to the above does switching over to a low pro system really warrant the effort anyway? As the first post says there seems to be no clear consensus on using low pro chain - that says a lot in itself!



I'm not sure how others (intend to) use LP but my experience so far on my 50 cc Plastic Fantastic Homelite 340 with a 20" bar is that it is faster than regular 3/8 to break up short logs that are smaller than 16" in diameter. I then resaw these on my 19" conventional bandsaw. Because the LP has shown a lot of promise I have bought a 25" .050 bar and will use it with a 441 to be able to tackle logs up to 21". At this stage I don't intend using it on anything bigger because the wood I cut is too hard and the bigger powerheads will almost certainly over stretch the LP chainb.

One reason why 404 has the potential to cut faster than 3/8 is that it has a bigger chip carrying capacity - but it also cuts a comparatively bigger kerf so the overall gain is not always as great as might be imagined. This gain is more visible in softer wood using big saws where cutting is limited by the chip carrying capacity of the chain. 

In wood above about 1900 lb Janka hardness, milling is usually wood hardness limited so making a narrower chip is advantageous. A 3/8 chain makes a narrower chip than a 404, but then there are more cutters in the kerf. One way to reduce the number of cutters in the kerf is to use skip chain but the way full comp chain (of any size) cuts, is not the way most people think. Only about every 3rd or 4th cutter is cutting a serious chip, so it's already acting a like skip chain to begin with. The normal cutting action results in all chain porpoising up and down off the bar with only every cutter on top of the wave cutting significant wood and this is why semi-skip or full skip makes little difference compared to regular chain, if anything skip chains go blunter quicker because there are fewer cutters. To see a significant benefit in load reduction on a saw using skip, one needs to go to 3 or 5 skip chain.

One reason why operators prefer 404 over 3/8 is because they do not realize that because 3/8 cuts a smaller kerf it can operate with a higher cutting angle which creates deeper chips. Whereas, raising the cutting angle on a 404 chain to the same extent can just bog the saw. The 404 has other advantages eg if the chain strikes something large, the cutters are likely to stay on the chain compared to the 3/8. In terms of going blunt I agree 404 tends to stay sharp a little longer. The main thing for me is will a chain make it through a slab without having to drag it out of the kerf to resharpen it. As long as it gets to the end of the cut whether its 404 or 3/8 it's going to have to be touched up anyway. Up to about 12' long in big (36") hard wood (36 sqft of cut) the 3/8 chain is OK. Above this area I would consider going to 404.


----------



## Rob D

Thanks Bob. That's definately given me some food for thought!


----------



## mtngun

Trigger-Time posted some excellent info on picco chain a while back. I thought we had determined that Stihl Picco was somehow different than Oregon/Carlton lo-pro, but then I went back and re-read those old threads and ...... it's as clear as mud. 

In any event, I have no plans to run picco/logosol chain because of the price, nor do I have any picco chain on hand to examine and compare.

However, I would like to know if picco sprockets are suitable for Oregon/Carlton lo-pro.

Since Picco is the same pitch as lo-spro, and since the picco drive sprocket diameter is a little larger than a 3/8 drive sprocket, I suspect the Picco drive sprockets would work perfect with lo-pro -- unless there is big difference in the shape of the drive links.

Here is some of Trigger-Time's info on picco sprockets from  this thread.


> Picco 7T.....1.433 dia = 4.502 circumference..........+0.167
> Reg. 3/8 7T 1.380 dia = 4.335 circumference
> 
> Picco 8T......1.664 dia = 5.260 circumference........+0.183
> Reg. 3/8 8T..1.606 dia = 5.077 circumference


----------



## huskyhank

mtngun said:


> snipped....
> 
> Since Picco is the same pitch as lo-spro, and since the picco drive sprocket diameter is a little larger than a 3/8 drive sprocket, I suspect the Picco drive sprockets would work perfectly with lo-pro -- unless there is big difference in the shape of the drive links.



If you know the pitch to be the same this will work. It would sure be nice to compare the drive link shapes. I wonder if you can get an engineering drawing for the chains? Or do you know someone with a machine shop who has high end metrology equipment?


----------



## Mad Professor

If you look at the conversion charts *from the chain manufacturers*:

stihl 63 PM (picco) = carlton NC1 = oregon 91VS (low-pro) = windsor 50R

It would be nice if someone manufactured the CORRECT rim (e.g. NOT regular 3/8) sprocket to fit the bigger saws.

You can adapt a small style 036 rim type drum to run on the bigger stihls but it will have a little wimpy bearing, this will allow you to run a stihl picco rim.


----------



## mtngun

Mad Professor said:


> stihl 63 PM (picco) = carlton NC1 = oregon 91VS (low-pro) = windsor 50R


You are probably right about picco being Stihl's equivalent to lo-pro. I owe you an apology for not listening to you sooner. But, this has been a confusing subject, and few of us have all the components available to examine and compare.


----------



## Brmorgan

Rob D said:


> Who uses 404 for milling ?
> 
> .404 is my main chain for milling.
> 
> Personally I have found it to be the fastest over a number of cuts in that it seems to retain the best stay sharp quality. And I find I mill quick with it.
> 
> I know the leading edge (or corner) is the critical thing with a chainsaw chain and this will be the same size low pro or not...... but I just find that .404 chain keeps cutting better for longer.
> 
> I may not be right this is just my own experience



I have a 33" .404 milling chain for my 090, but that's just because the .404 is the only bar I have for it! I don't have to worry about bogging that saw no matter how I file it, either! I'd love to get a 9 or 10 pin 3/8" sprocket to really make that thing sing though. Just not enough RPMs to warrant using it over the 395 in that size of wood.

Mtngun and BobL:

I just picked up a brand-new 25" .050 bar for that 066 I just finished rebuilding. Admittedly, the LP chain does ride quite high on the nose sprocket teeth on this one since they're brand new. On the old bar I've been using it sat down nice and tight on the nose. In any event, I used it all day yesterday with a brand-new Oregon 91VS chain filed at 25° in 12-18" W.R. Cedar, and yes it did stretch a bit on the first couple cuts, but it cut beautifully smooth and without incident. I forgot the camera though so I can't give a shot of the smoothness of the cut - but I bet a 1/32" pass on the planer would have taken any saw marks out, it was that good. And FAST! Not sure I feel the need to buy actual low-pro milling chain anymore, really. Anyhow I'm heading outside to work on that stuff a little bit right now - another beautiful sunny day here. I'll take some pics.


----------



## Kicker_92

BobL said:


> One reason why operators prefer 404 over 3/8 is because they do not realize that because 3/8 cuts a smaller kerf it can operate with a higher cutting angle which creates deeper chips.



What is the limit for cutting angles? I'm using 8° for softwood with 3/8" semi-skip right now. Is there a point where the cutter becomes less efficient? (10°, 12°, 20°?)


----------



## BobL

Kicker_92 said:


> What is the limit for cutting angles? I'm using 8° for softwood with 3/8" semi-skip right now. Is there a point where the cutter becomes less efficient? (10°, 12°, 20°?)



Assuming the chain is already cutting, the cutting efficiency (size of chip) keeps increasing with cutting angle (CA) utilthe powerhead finally bogs. I could suggest you just try gently increasing the CA but before you do perhaps you would like to see what the raker depths are for different CAs.

For those that are unsure - this is what I mean by cutting angle.





This table shows the raker depths for various cutting angles (CA) in red, at various gullet widths in blue.




A "normal" CA, eg for a chain fresh out of the box chain is 6º, so this means using the green line at different gullet widths. 

Rather than mucking about with measuring gullets and depths I find it easier to use a digital angle finder (DAF) and file the raker and measure the angle direct with the DAF. For those that still confused, check out the FOP sticky in the CS forum. Towards the end of that thread (post #68) I posted a movie about how I do this. Please note I don't do this every time I touch up the rakers. I touch up the cutters (2-3 strokes) after about every 32 sqft of milling, whereas I free hand the rakers (~2 strokes) after every 3-4 touch ups. I reset the rakers like this off the mill after every 2-3 full days of milling when I swap out the chain and flip the bar.

Note after the cutter is about 1/4 worn an FOP only creates a 4.6º CA which is on the wimpy side of CA's especially for bigger saws. 

As a guide I can cut up to about 50" wide very hard wood with my 880 using a CA of 6º on a 3/8 chain. Currently the raker depths on some of my chains are around 0.045" and look quite squished but I have never made such lovely fat chips as this with used chain. If I was going to cut bigger wood than than this, in my harder woods I have several options, using 3 or 5 skip, or reducing the CA, or using a bigger powerhead.

Skip chain, softer wood and smaller cutters should permit use of a higher CA without bogging the saw. Although I haven't tried it I don't think there is much advantage in going to a higher CA for skip chain unless it is something like 3 or 5 skip chain. Regular skip may have other advantages especially in softwoods like more room for sawdust and less cutters to sharpen but these are less of an advantage in harder woods.

With an 090 a 9º CA would not be out of the question for shorter bars in softer wood 

On a 30 HP Lucas slabber even using 404 chain, a 10º CA is possible.

At some point or other the chain will eventually run out of raker, if so you should be using 404 or harvester chain.

BTW Old timers didn't worry about any of this. If their chains weren't cutting they would keep filing their rakers until they made chips again. The FOP is a distinct improvement on the fixed gauge supplied by most CS and chain manufacturers who probably think this is too technical for weekend warriors to work out. I don't blame them - it probably reduces the number of kickback incidents that would result from making mistakes in raker adjustment and increases new chain sales.

What's this got to do with lopro? Well, in theory the smaller LP cutter should permit a higher cutting angle (provided the saw can pull the chain and the chain can cope with the strain). I'm planning on using a 25" bar on a 441. I'll start with 6º but 7 or even 8º might not be out of the question, even with the 441. On a 660 an 8º CA may just wreck the chain?


----------



## Mad Professor

mtngun said:


> You are probably right about picco being Stihl's equivalent to lo-pro. I owe you an apology for not listening to you sooner. But, this has been a confusing subject, and few of us have all the components available to examine and compare.



I've been running the 63 PMX (the milling stuff only available via logosol) on my 066 and M5 mill since 1998. 

Most of the stuff is for grade, cherry heartwood, so I like the narrow kerf/less waste/sawdust. 

I've only snapped one chain (24") so far, when a vibration set up and I kept on cutting, instead of backing out (MY fault). Nothing lost except the chain.......which needed a repair.

The less expensive equivalents might be a good buy, but you loose a bunch of tooth grinding them back to a milling angle, and a bunch of time grinding.

The other pisser is the $40 picco spur sprocket for the 066. The adapt to a small/early 036 that will take a picco rim is tempting, but if you trash the diminutive bearing you might trash your $$$$ crankshaft.

The other option is 0.325, for which there are rims to fit the medium/big saws. I've not tried this but others report good results.

I hope to skid some logs and will post some (milling) pics soon.....got to do something while the sap is boiling!!!


----------



## Philbert

BobL said:


> This table shows the raker depths for various cutting angles (CA) in red, at various gullet widths in blue.



Thanks again BobL!

Do you have some simpler rules of thumb that can be generalized, based on your experimentation? Specifically, I would like to know your recommendations for cutting angles for: 
- cross-cutting hardwood;
- cross-cutting softwood;
- ripping hardwood; 
- ripping softwood;
- etc.

I realize from your post above that it will vary with the powerhead and chain, but it would be nice if it could be summarized, e.g. _'6º for general cross-cutting, Xº for ripping, Yº for . . . '_ recognizing that some adjustments will always need to be made from these starting points to optimize a cutting situation.

Philbert


----------



## BobL

Philbert said:


> Thanks again BobL!
> 
> Do you have some simpler rules of thumb that can be generalized, based on your experimentation? Specifically, I would like to know your recommendations for cutting angles for:
> - cross-cutting hardwood;
> - cross-cutting softwood;
> - ripping hardwood;
> - ripping softwood;
> - etc.
> 
> I realize from your post above that it will vary with the powerhead and chain, but it would be nice if it could be summarized, e.g. _'6º for general cross-cutting, Xº for ripping, Yº for . . . '_ recognizing that some adjustments will always need to be made from these starting points to optimize a cutting situation.
> 
> Philbert



Sorry but there are too many variables and even personal saw operator pressure preferences. Some operators like to hoik on their saws while others like to feather them etc - this will be very sensitive around the "chain grabbing point".

Some other variables that have to be included are;
Bar/chain length or more importantly wood cut width, wood hardness, wood cleanliness, chain gauge, skip, cutter size and cutter profile, as soon as you mess with any of these that will affect the optimum CA.

I only occasionally cross cut so I have not been able to devote any time to experimenting with optimising this sort of cutting.
I only have access to hard or harder or incredibly hard wood so I can't comment on softwood either.

About the only variation I can comment on is that using a 7º CA on a 3/8 full comp chain on an 880 (with a muffler mod) doesn't grab in my hardwood up to about 40" in hard wood. Above that it gets grabby and I have to hold back the saw so 6 to 6.5º is about optimum. 7º might be OK with Skip under the same conditions

The starting point for any saw is the factory recommended bar and chain and raker depth setting.
This is normally ~6º for most saws/chains.
Then vary the CA gently upwards until the saw bogs and back it off from there.


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## Brmorgan

Bob, I assume when you say "cutting angle" it's equivalent to what I would more commonly call the "hook angle"? If so I probably run about 10° on most of my chains, firewood, milling, or whatever. I've never measured though. I usually find the first pass a little bit grabby after freshly sharpening that way, but it seems to cut faster with less load on the saw if you control the cut. Of course I'm not dealing with wood nearly as hard or wide as you usually do though.

Here's a pic of the new Oregon 91VS on the brand-new Stihl bar I've been using the last couple days:






As I noted, it rides a bit high on the sprocket. However since the whole idea of a sprocket tip is to keep the chain from riding on the bar nose in the first place, I don't really see it as much of an issue. I checked and even a new standard 3/8" chain sits a little high too. The hook angle on this chain is a little on the low side still; even my 5/32" files seem a bit big for it because they're already starting to bite into the tie straps and it's only been filed 4 times, and even then only touchups. This Oregon stuff sure has small cutters to start out with. Here it is beside some WP/Carlton LP ripping chain:






The Oregon is on top. As you can see the Carlton has much more cutter life, and costs less to boot. But the Oregon cuts just as quick and leaves just as smooth of a surface.


----------



## Brmorgan

Made a quick video today of three passes with the Oregon LP chain on an 8-pin rim on the rebuilt 066 in 11" Pine:

*http://www.youtube.com/watch?v=zZt4nFXKzsg*


Here's what the milled surface looked like on today's cuts:











And here's what the Carlton produced last night on the same bar & sprocket:






To me the final result is indistinguishable and the cut speeds are pretty close too. 


Here's what I ended up milling in total today:






I got 21 boards between 7-12" wide from the four Pine logs I cut. I also milled the remainder of an old spalted Birch piece I've had for a couple years which just thawed out of the snowbank, and a Juniper log as well.

The Birch looks really nice, but is pretty soft in areas. It might take a lot of CA glue to make it workable. They're 1-1/2" thick and bookmatched quite well though, so I'm going to do my best to save them.


----------



## BobL

Brmorgan said:


> Bob, I assume when you say "cutting angle" it's equivalent to what I would more commonly call the "hook angle"? If so I probably run about 10° on most of my chains, firewood, milling, or whatever. I've never measured though. I usually find the first pass a little bit grabby after freshly sharpening that way, but it seems to cut faster with less load on the saw if you control the cut. Of course I'm not dealing with wood nearly as hard or wide as you usually do though.



CA is different from hook. CA is the angle between 1) the raker, 2) the cutter top plate, and 3) the wood.
Like this.





CA has been discussed in grimy detail in the CS forum sticky.
http://www.arboristsite.com/showthread.php?t=114624

In summary I end up describing that one can forget about worrying about what raker depth to use because ideal raker depth changes with cutter/gullet length, and just concentrate on maintaining a fixed cutting angle for a given cutting setup. 

Its probably has less of an impact on cutting softwoods, but I have never see such consistently fat chips from well used before in the hardwoods I cut. Everyone that has had trouble with getting nice chips from old chains is really impressed that they can get back "new chain cutting action" by using (aspects of) this approach.

As I have already said, old timers did it by just continually filing their rakers till they got chips. The FOP approach is a rough approximation and a tad on the wimpy side. This just quantifies the process enabling (particularly) newbies to have a bit more control over what they are doing


----------



## Brmorgan

Ah yes, of course I remember now. I've never bothered to measure that either! I'm by no means an old-timer but that's more of the approach I take. I also keep an eye on the rakers - if they're getting really polished down smooth from being pushed into the wood, I knock a couple strokes off of them again.


----------



## Kicker_92

BobL said:


> What's this got to do with lopro? Well, in theory the smaller LP cutter should permit a higher cutting angle (provided the saw can pull the chain and the chain can cope with the strain). I'm planning on using a 25" bar on a 441. I'll start with 6º but 7 or even 8º might not be out of the question, even with the 441. On a 660 an 8º CA may just wreck the chain?



Another option that increasing the cutting angle is to gear up the saw. I've got some loops of 3/8" lo-pro to go on the 85cc, and the 7-pin sprocket might be a tad on the slow side. For a 20" wide cut, it should be able to pull that smaller chanin with an 8-pin, or maybe even a 9-pin if I can find one.


----------



## Brmorgan

My 066 does really well on an 8-pin in up to 20" of wood (as in the video I posted on the last page if you missed it). I haven't tried longer though because that's the most clearance I can get from the 25" bar once it's mounted up on the mill. I wouldn't dare a 9-pin really; maybe you could get away with it up to 10" or so. But who knows. For the price of them I'm not about to try it on a whim.  I find the 8-pin somewhat easy to bog out if the chain is freshly sharpened a bit aggressively anyway unless I make sure to take extra care to control the cut.


----------



## BobL

Kicker_92 said:


> Another option that increasing the cutting angle is to gear up the saw. I've got some loops of 3/8" lo-pro to go on the 85cc, and the 7-pin sprocket might be a tad on the slow side. For a 20" wide cut, it should be able to pull that smaller chanin with an 8-pin, or maybe even a 9-pin if I can find one.



Another possible way of putting this to good use when doing long days in the field is to start out with aggressive rakers and run a 7 pin sprocket. Then after touching up the cutters 3-4 times swap to an 8 pin sprocket.

This saves the hassle of doing the rakers in the field.


----------



## LumberJeff

*lo-pro vs 3/8*

the way i understood from other threads on this site is; lo-pro is.365 pitch and 3/8 is .375 pitch. correct me if I am wrong. please


:newbie:


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## mtngun

LumberJeff said:


> the way i understood from other threads on this site is; lo-pro is.365 pitch and 3/8 is .375 pitch. correct me if I am wrong. please


Lo-pro seems to be 0.365" - 0.366".

3/8 seems to be 0.367" - 0.368". Perhaps 0.001" - 0.002" longer than lo-pro, not a true 0.375".


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## Brmorgan

All of which are right out the window anyway after the first board is cut with a new chain and it starts to stretch.


----------



## ray benson

LumberJeff said:


> the way i understood from other threads on this site is; lo-pro is.365 pitch and 3/8 is .375 pitch. correct me if I am wrong. please
> 
> 
> :newbie:



Check a 100' roll of each. They will have the same number of drive links.
Pitch is the same.


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## mtngun

mtngun said:


> The 3/8" x 0.063" times were 151 seconds and 146 seconds in that order. Average = 148.5 or 0.64 inches per second.
> 
> The lo-pro times were 137, 139, and 137 in that order. Average = 137.7 or 0.69 inches per second.


Since doing that test with the lame 066BB, the saw was fitted with a dubious OEM jug and a pop-up piston. The jug also had my first ever port job, with all its imperfections. The rings never sealed well, and compression was stuck around 120 - 125 psi despite the pop-up. Plus, there was evidence that the plating was continuing to flake off the jug (the plating had been damaged by sawdust in a previous incident). I decided to abandon that top end, but wanted to do a speed test before moving on.

Another 12.5" cant, ponderosa pine, possibly from the same tree.

Same 2 chains as before except, while last time the chains were fresh out of the box, this time they had been sharpened to factory specs.

3/8 x 0.063 Woodland Pro milling chain -- 0.565 inch/sec first pass, 0.49 inch/sec 2nd pass. Revs began at 10,500 but gradually dropped off to 9,100 by the end of the second pass. 

lo-pro x 0.050 Woodland Pro milling chain -- 0.73 inch/sec first pass. Revs began at 11,000, then settled into 10,000. During the last foot of cutting the saw seemed to lose power and I had to baby it to maintain 9000 rpms. 

When the saw lost power, I worried another chunk of plating had flaked off, and I didn't want to risk damaging the bottom end, so I didn't do a second pass with lo-pro as originally planned.

Today the _*low pro was 29% faster*_ than the 3/8. 

Hard to say how the OEM top end compared, speed-wise, to the lame BB. The OEM beat the BB with lo-pro, but the BB beat the OEM with 3/8. Could be due to chain sharpness, or to variations in the wood. I really *NEED* a dyno.


----------



## mtngun

Another day, another 066 top end, same 12.5 pine cant.

This is the popped & ported 066BB, which has lots of freeport, plus the rings refused to seal well. 128 psi last time I checked. 

I had previously tuned it by ear to 13,500 rpm, where it was still blubbering. It didn't clean up until 14,000+.

3/8 lo-pro, 1st pass 0.76 inch/sec. It seemed happy running at 10,400 rpm. I had decided to skip wedging the kerf to save a few seconds. But, about six feet into the log, it balked and would barely run. I let it idle for a couple of seconds, then tried it again, and it took off. Not sure what happened -- partial siezure ? the 2 big knots at that spot ? or the bar being pinched in the kerf, since the kerf had not been wedged ?

I was a little paranoid about the engine overheating, so I retuned to 12,000 rpm WOT.

3/8 lo-pro, 2nd pass 0.76 inch/sec. This time it wanted to run around 9500 rpm. Funny how the cut time ended up exactly the same ? Perhaps the rich tuning allowed it to take a bigger bite ? 

This time I wedged the kerf at the start end of the log. Yet, the engine still balked about six feet into the cut. Once again, I let it idle for a couple of seconds, and then it was willing to resume cutting. 

I had planned to do a comparison test with 3/8 chain, but decided against it because of the mysterious stalling problem. 

Despite the engine problems, the 0.76 inch/sec speed is the 066's best to date.


----------



## 820wards

BobL said:


> Another possible way of putting this to good use when doing long days in the field is to start out with aggressive rakers and run a 7 pin sprocket. Then after touching up the cutters 3-4 times swap to an 8 pin sprocket.
> 
> This saves the hassle of doing the rakers in the field.



Bob,

i have been using a 7 x .404 and just got a 8 x .404 to try on the next wood I mill. I also have my rakers set at .045" because of the torque in my 820 motor. Do you know what percent of chain speed I can expect from switching to the 8 x .404?

jerry-


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## BobL

820wards said:


> Bob,
> 
> i have been using a 7 x .404 and just got a 8 x .404 to try on the next wood I mill. I also have my rakers set at .045" because of the torque in my 820 motor. Do you know what percent of chain speed I can expect from switching to the 8 x .404?
> 
> jerry-



8/7 or 1/7 = 14% more, it's not a lot but it's better than nothing.


----------



## mtngun

Some good news and some bad news for lo-pro fans.

A new speed test, with the new-style Bailey's 066 BB kit. Squish was set to 0.023", otherwise, the kit is unaltered. Saw was tuned to 13,000 RPM WOT at the beginning of the test. 7 pin rim. The usual 12.5" wide pine cant.






Two passes were made with Woodland Pro lo-profile milling chain, then two passes were made with WP 3/8 milling chain.

lo-pro x 0.050" 1st pass 0.79 in/sec, 2nd pass 0.83 in/sec, average 0.81 in/sec. The saw seemed happiest pulling 10,000 - 10,400 RPM. A virgin chain was used for today's test as will be explained later.

3/8 x 0.063" 1st pass 0.56 in/sec, 2nd pass 0.67 in/sec, average 0.62 in/sec. Saw seemed happiest pulling 9100 - 10,000 RPM. The chain was nearly new, having only been used for this series of speed tests.

Here is a summary of all the milling speed tests I have done so far, ordered fastest to slowest:

Lo-pro
0.81 in/sec new "as-is" BB
0.76 in/sec wood ported 2008 vintage BB with chattered bore
0.73 in sec wood ported OEM with damaged bore
0.69 in/sec "as-is" 2008 vintage BB with chattered bore
*0.75 in/sec average for all tests*

3/8" x 0.063"
0.64 in/sec "as-is" 2008 vintage BB with chattered bore
0.62 in/sec new "as-is" BB
0.53 in/sec wood ported OEM with damaged bore
*0.60 in/sec average for all tests *

On average, the lo-pro is 25% faster than 3/8", at least on this peaky 90cc saw. A torky saw might give completely different results.

But, I ran into a problem. I had noticed the lo-pro chain was an extremely snug fit in the bar. At first, I assumed it was because the bar was brand new and not broken in yet. However, it seemed to get worse with each use, instead of getting better. So..... I examined the drive links very carefully. A micrometer confirmed the worst -- the drive sprocket is hammering the drive links and peening the edge. The drive links on this chain -- which has only been used for these speed tests -- now measure 0.057"- 0.061". I'm going to have to painstakingly dress each drive link before this chain can be used again. :bang:





With the typical worn and sloppy bar groove, you might not notice the peening problem, but my new Stihl bar doesn't like it one bit. 

Now that I have data showing that lo-pro is 25% faster, I can justify buying the expensive special spur sprocket. Hopefully, that will solve the peening problem.

I'm also going to look into the possibility of turning down 0.404" rims to fit lo-pro. I'll have to fabricate a mandrel to hold the rims while they are being turned in the lathe, so that project may take a few months.


----------



## DRB

Thanks for the continued tests. We need to get lo pro figured out. Thanks for taking one for the team before I get around to trying it out.

Is the lo pro kerf smaller than regular 3/8 ripping chain?


----------



## mtngun

DRB said:


> Is the lo pro kerf smaller than regular 3/8 ripping chain?


Yes.


----------



## Brmorgan

My low-pro cuts about 9/32" kerf. Very narrow.


----------



## mtngun

Just checked the drive links on the virgin lo-pro chain used in yesterday's speed test. They are peened to 0.060", after only being run for 4 minutes ! ! !

I won't run lo-pro again until I have a more appropriate drive sprocket. 

It will be interesting to see if the peening goes away with a better fitting sprocket.


----------



## Andrew96

At any one time I'd assume there would be 3-4 tangs engaged taking the full power of the saw. That might just be the point at which the drive tang is overloaded...producing the peened edge. Maybe it's just the amount of power through the drive tangs more than the ill fitting sprocket. I'm sure I'm not the only one interested to see once you get the proper one sorted.


----------



## mtngun

Andrew96 said:


> At any one time I'd assume there would be 3-4 tangs engaged taking the full power of the saw.


I think I posted a pic of a cut-away sprocket, several pages back, showing that only 2 tangs engaged the sprocket (versus 3 tangs engage when the chain fits propertly).

It doesn't sound like a big deal, but I guess it is.

I'm pretty sure I can turn down a 404 sprocket to the correct diameter for lo-pro, just got to figure out a mandrel to hold the sprocket in the lathe.

I think if we get the drive link problem sorted out, it'll be smooth sailing after that. Smooth, *25% FASTER *sailing.


----------



## BobL

mtngun said:


> Just checked the drive links on the virgin lo-pro chain used in yesterday's speed test. They are peened to 0.060", after only being run for 4 minutes ! ! !
> 
> I won't run lo-pro again until I have a more appropriate drive sprocket.
> 
> It will be interesting to see if the peening goes away with a better fitting sprocket.



I don't understand what you mean by peened to 0.060. Do you mean the links have been thinned from 063 to 060?


----------



## Brmorgan

I think he means the front of the drivers are starting to mushroom from being forced against the drive pin of the sprocket. I've noticed it on all my chains but have never really paid much attention to it. Next time I'm up top at the shop I'll take a pic of the older low-pro chain that has two seasons of cutting on it. I have no idea what it looks like though.

I'm a little lost on the logic of using a .404 sprocket though... Please explain?

To turn it down, could you chuck an old clutch drum by spreading the jaws outward to grab the inside of the drum (just like the clutch would) and install the rim on the splines with some way of keeping it tight? It might not be dead accurate but it's not like you're turning a piston or something.


----------



## mtngun

BobL said:


> I don't understand what you mean by peened to 0.060. Do you mean the links have been thinned from 063 to 060?


It's an 0.050" gage chain. The drive sprocket has hammered the edge of the drive links and caused them to bulge.


----------



## mtngun

Brmorgan said:


> I'm a little lost on the logic of using a .404 sprocket though... Please explain?


The unproven theory is that all rim sprockets are basically the same except for OD. The OD of a 3/8 x 7 is too small for lo-pro. The OD of a 404 x 7 is too big for lo-pro. 

But, if I had a way to chuck the 404 rim in the lathe, I could turn it down to fit lo-pro. 

Just a theory, and it may not work.

I've thought about using an old clutch rim as a starting point for the lathe mandrel, but bear in mind that the rim is hardened tool steel and very, very tough to cut on a lathe. The mandrel must have an iron grip on the rim. 

I will probably have to make a mandrel from scratch, and heat treat it.


----------



## Andrew96

Well two tangs engaging might explain it. To turn down that 404, you might choose to spin it and grind (either on your lathe or somewhere else) as I doubt you'll be able to hold it properly with and iron grip. Any sandwich arrangement mandrel will hold it accurately enough to grind it.


----------



## billstuewe

I have been using Stihl "Picco" chain (lo-pro) since 11/2001 for milling with a Logosol. They supply a Stihl picco spur sprocket made for them from Sweden. It is not available to your Stihl dealer here in the USA. They say I am crazy until I produce the sprocket with the part number--which they cannot get. It works just fine and will not peen the back of the drivers. A regular 3/8 sprocket will in a matter of minutes. I have not gotten my head around that but I am told that it is because the picco is actually .365 ga instead of .375 (3/8). BUT, a 100' spool of 3/8 chain has 1640 drive links and a 100' spool of picco chain has 1640 drive links!!!!! Go figure? There is a difference however because one peens the drive links and the other does not. I know of no drive sprocket that will work on picco and fit the big block saws like 088 or 084, just the 066. 
mtngun, If your theory of sprocket diameter is correct and you turn down a .404 sprocket I think you will then have a regular 3/8 sprocket??? If it works, let me know. Having a rim sprocket would solve the problem of getting a picco sprocket for the big block saw but then you sill have the problem of getting a .50 ga bar to fit a big block mount if you are wanting to use on an 088. I also thing the 088 will break more lo-pro chain due to its extra power.


----------



## mtngun

billstuewe said:


> I have been using Stihl "Picco" chain (lo-pro) since 11/2001 for milling with a Logosol. They supply a Stihl picco spur sprocket made for them from Sweden. It is not available to your Stihl dealer here in the USA. It works just fine and will not peen the back of the drivers. A regular 3/8 sprocket will in a matter of minutes.


If the 404 rim doesn't work out, I plan to fall back on the Logosol spur sprocket. In fact, I will probably go ahead and order the Logosol sprocket. No one likes spur sprockets, but it is a solution, and the lo-pro speed advantage justifies the expense.



> I have not gotten my head around that but I am told that it is because the picco is actually .365 ga instead of .375 (3/8). BUT, a 100' spool of 3/8 chain has 1640 drive links and a 100' spool of picco chain has 1640 drive links!!!!!


There is a lot of confusion about that. Both lo-pro (and presumably picco) and 3/8 are actually 0.367", give or take. However, the lo-pro side links are not as tall, and that changes the way it sits on the sprocket. 



> mtngun, If your theory of sprocket diameter is correct and you turn down a .404 sprocket I think you will then have a regular 3/8 sprocket? ?? If it works, let me know.


 It'll have a larger OD than a 3/8 sprocket, similar to the small spline picco rim.

If it works -- big *if* -- I'd probably be willing to supply them to others. 



> you sill have the problem of getting a .50 ga bar to fit a big block mount if you are wanting to use on an 088. I also thing the 088 will break more lo-pro chain due to its extra power.


I'm not crazy enough to use lo-pro on a 120cc saw, just the 066.  

My 084 will either use 3/8 or .325, 0.063" gage. It'll cost me quite a bit more to set up for .325, but Aggiewoodbutcher seems to think it is worth it.


----------



## Brmorgan

mtngun said:


> The unproven theory is that all rim sprockets are basically the same except for OD. The OD of a 3/8 x 7 is too small for lo-pro. The OD of a 404 x 7 is too big for lo-pro.
> 
> But, if I had a way to chuck the 404 rim in the lathe, I could turn it down to fit lo-pro.
> 
> Just a theory, and it may not work.
> 
> I've thought about using an old clutch rim as a starting point for the lathe mandrel, but bear in mind that the rim is hardened tool steel and very, very tough to cut on a lathe. The mandrel must have an iron grip on the rim.
> 
> I will probably have to make a mandrel from scratch, and heat treat it.



If I remember right, the ID of the standard large spline drive rims is very close to 7/8". I remember 4-5 years ago when I started fiddling around with building a carriage CSM (when I knew nothing about them) I was trying to figure out a way of driving the sprocket, and I remember it fitting very well over a piece of 7/8" threaded rod. What if you were to weld a little tab on some of that stuff to fit into one of the splines in the rim, and then spin a nut down on either side of it to lock it into place? 

As for removing material, what about a good 1/2" cylinder carbide burr in a die grinder, rotating opposite to the lathe? I've done this with decent success on softer stuff.


----------



## huskyhank

I think "bushing" or "re-lining" a proper lo-pro sprocket with a large spline center my be the way to go. Or it may be possible to machine the larger spline directly into an existing lo-pro sprocket. Using EDM perhaps??? If the sprocket teeth and the drivers don't mate they'll bugger every time. So if you have that part whipped then figure a way to get that part on the large spline.


----------



## mtngun

Ordered the Logosol pico spur sprocket last night, $51.45 delivered ! :censored:

By the time it gets here, I'll probably have the 404 rim made and won't need the Logosol. 

I am determined to make the lo-pro work right, one way or another.


----------



## mtngun

Some updates......

I painstakingly filed down the peened drivers -- all 228 of them -- wearing out 3 files in the process.  I hope I don't have to do that again. 

The Logosol picco spur sprocket arrived, so I am cleared to resume using lo-pro, assuming the Logosol sprocket solves the peening problem. 

BTW, the Logosol spur is a Stihl part, #1122-640-2006. I dunno if you can order it at your Stihl dealer or how the Stihl price compares to the Logosol price.

I was going to order a bunch of 404 x 7 rims to experiment with, but it turns out all the new Oregon and Bailey's rims are "ported," cut away on the backside. Supposedly the porting helps clear chips, but I've never had any problem with non-ported rims clogging up with chips. More likely, the porting saves a penny in material costs.

The problem with the ported rims is that if you turn them down to fit lo-pro, then you may cut into the ported part of the rim and the chain will be free to fall off the rim. I don't know if it actually will fall off, but it could. Nor do I know for sure that it will be necessary to cut that deep, anyway. I'll just have to experiment and find out.

Since I have one non-ported 404 x 7 rim on hand, I'll probably go ahead and modify it, just to test the theory. If it works, then I'll try one of the new ported rims. This will all take a while, and I haven't started on it yet because I've been busy on the 084 project.

Left to right, Logosol sprocket for 066, NOS Oregon non-ported 404 x 7 rim, and new "ported" Oregon 404 x 8 rim wrapped tightly with lo-pro, which isn't meshing well..






As best I can measure, the OD of the Logosol spur is 1.436", compared to 1.433" for the Stihl Picco rim as reported by Trigger-Time. That's only 0.055" bigger than a 3/8" rim.


----------



## KiwiTony

Is there a chance that you could take a few shots of the 1122...2006 with
both a regular 3/8 chain,and the Lo-Pro wrapped around it? Similar to what you have on the 1st entry to this thread with the nose sprockets.It looks like the 1122...2006 sprocket has a different profile.Certainly different to the 1122/02 that I am looking at.Thanks.


----------



## mtngun

KiwiTony said:


> Is there a chance that you could take a few shots of the 1122...2006 with
> both a regular 3/8 chain,and the Lo-Pro wrapped around it?


I'll try to remember to do that tomorrow night.

Tonight I made the mandrel for turning down rims. It was a late night in the shops so no pics yet.


----------



## mtngun

The Logosol picco spur tightly wrapped with lo-pro.





Logosol picco spur tightly wrapped with 3/8.





At first glance, there doesn't seem to be a big difference in how they fit. The proof will be in how the drivers hold up.


----------



## KiwiTony

In the top photo,virtually all the side links of the lo-Pro chain are snugged down onto the driving dogs.--The std chain actually goes "out of synch" as it progresses around the spur.Only 3 or so side links actually rest on the dogs.

To my way of thinking,the same would apply if a Lo-pro chain was put onto a regular 3/8 spur.The side links would come out of synch,thus more of the driving load would be transferred via the cutter tang. It is tricky to describe,but maybe that is the cause of your peening,and resultant hand filing.

The profile of the sprocket dogs are definately different between the Lo-Pro and standard spur.And by the look of your photos,the drive tangs on each chain seem to be a little different as well.

Great photos and interesting stuff.


----------



## mtngun

I used a CAD program to layout a 7 pin sprocket for lo-pro chain, 'cuz I'm getting ready to cut a 404 rim to fit lo-pro, and I'm trying to convince myself that I know what I am doing.  

A lo-pro tie strap is 0.393" long, center-to-center, as best I can measure. It's very tough to measure accurately, so if you measure your lo-pro chain, you may come up with a slightly different number.

A lo-pro tie strap is 0.172" tall, mid-way between the rivits. It is actually a curved shape, and of course it wears with use, so once again, if you measure your lo-pro chain, you may come up with a slightly different number.

A lo-pro drive link is 0.339" long, center-to-center, as best I can measure.

Wait a minute, you say, isn't lo-pro supposed to be.366" per link ?  

Well, if you average the .339" drive link and the 0.393" tie strap, you get 0.366". 

Ah.......... 

Now, imagine a loop of lo-pro with 14 links -- 7 tie straps and 7 drive links. Lay out that imaginary 14 link loop on CAD and use CAD to determine the rim diameter that will fit that loop perfectly. 





I came up with 1.426", but in real life lo-pro drive sprockets seem to be 1.433" - 1.436." It's possible that the difference is due to my measurement errors, but I suspect the sprockets are deliberately made slightly oversize to allow for normal wear.

Some quick and dirty measurements on 3/8" chain show about the same lengths for the tie strap and the drive link. The main difference is that a 3/8" tie strap is about 0.283" tall vs. 0.172" tall for lo-pro. A 3/8" rim must be smaller to allow for the taller tie strap.


----------



## mtngun

KiwiTony said:


> To my way of thinking,the same would apply if a Lo-pro chain was put onto a regular 3/8 spur.The side links would come out of synch,thus more of the driving load would be transferred via the cutter tang. It is tricky to describe,but maybe that is the cause of your peening,and resultant hand filing.


Exactly. Earlier in this thread, I posted a pic of lo-pro wrapped around a cut-away 3/8 rim, showing that only 2 lo-pro drive links were making good contact with the rim. The other drive links were "out of synch," as you put it.





I spent all evening doing the CAD drawing, and now there is no time left to cut the 404 rim sprocket. Oh, well, I'll try again tomorrow evening.


----------



## mtngun

Mandrel to hold rim in lathe. Mild steel, including the hand-filed keys. OK for this experiment, but if I get serious about modding rims, I may need to make a splined mandrel in 4140 pre-hard or something similar.









404x7 rim turned down to fit lo-pro (I hope). *Darned hard *to machine with carbide tooling ! ! ! If I do many of these, I'll either have to try some hi-tech bits, or else anneal the rims before machining.





Will it eliminate the damage to the drive links ? Dunno.  I'm working today, but maybe later this week I'll find time to do a few short tests.


----------



## huskyhank

The surface finish of the part looks plenty nice.

Annealing will cause more problems than it solves. These things look like investment castings and there's no telling what they are made of - how could you re-harden and know what you will get? Some kind of exotic insert may be best.

If you do make a splined arbor for this, it might be worth finding an old scrap crank and re-using the splined end. Probably lots easier than making a new one from scratch.

Good luck with this and thanks for sharing the project.


----------



## Brmorgan

I dunno, and please don't take this the wrong way because I really admire all the time/money/effort you're putting into this, but I really cannot be bothered by worrying about measuring such things down to thousandths of an inch, especially parts which are DESIGNED to wear as the chain/rim get used. As long as my LP chain on regular rim/bar combo keeps cutting straight and not breaking I'll keep using it as-is without worrying about the numbers.

As for the drive tangs only fitting two or three drive splines really well - isn't that normal? I mean, if you have 7 drive splines/pins over a 360° rim, only 3 should be driving the chain at most at any given time. The chain only wraps around the rear ~40% of the rim (not 50% because most bar tails are wider than the rims so the chain usually leaves and re-enters the rim on a slightly angled tangent, not parallel). Wrapping a chain tightly around a sprocket isn't a good way to tell if it's going to cause premature wear etc. in my opinion because it's never used like that in the field.


----------



## mtngun

Brmorgan said:


> As long as my LP chain on regular rim/bar combo keeps cutting straight and not breaking I'll keep using it as-is without worrying about the numbers.


I have no choice -- a standard 3/8 rim was severely damaging the lo-pro drive links, which in turn damaged the bar and created tremendous friction. Even if I didn't care about damaging a brand new Stihl bar, it was just a matter of time until the peening would have led to a broken chain.

The peened area had swollen to 0.055" - 0.060" thickness, some were even thicker. Imagine dragging that through a 0.050" bar groove ! ! !





After running for just a couple of minutes, the bar was too hot to touch because of the friction created by the damaged drive links. 

At first, I thought the friction was because the bar was brand new. I assumed it would go away as the bar broke in. Instead, the friction got worse and worse, which led me to examine the drive links.

One wonders how much power was wasted pulling the 0.060"+ peened drive links through the 0.050" bar ? How much faster would the chain cut if it didn't have to struggle with peened drive links ?

The damage to the drive links was in full evidence after making only 2 passes with a brand new chain -- about 4 minutes run time. That's a serious problem, my friend. :help:

Perhaps my saw is the only saw in the world that peens lo-pro drive links, but I doubt it. More likely I just happened to notice the problem because I was running a brand new bar, whereas the people who claim they don't have a problem are using worn bars ?

Reading back through the old threads on lo-pro/picco chain, I came across two or three reports of broken chains. At the time, it was always blamed on the inherent weakness of lo-pro chain, but now I wonder how many of those chains actually broke as a result of peened drive links ? 

Where's BobL when you need him ? 

All theory aside, peened drive links are not acceptable. They damage the bar, increase friction, and can eventually result in a broken chain.

I checked the drive links on some of my well-used 3/8 and .325" chains, to see if their drive links were peened, too. No, the old chains had little or no peening. So what is different about the lo-pro that causes peening on the drive links ? What else could it be other than the poorly fitting drive sprocket ? 

Anyway, I should have some answers in a few days. I'll make a pass with the picco sprocket, and check for peening. If it passes that test, I'll make a pass with the modified 404 rim and again check for peening. Apparently, the peening is nearly instantaneous, so it shouldn't take long to see if the new sprockets solve the problem.


----------



## Andrew96

mtngun said:


> So what is different about the lo-pro that causes peening on the drive links ? What else could it be other than the poorly fitting drive sprocket ?



It could be the drive link itself. 

Your assumption here that the drive tab on a standard and a low pro are the same...may not be correct. 
Maybe the drive link is made to a different hardness standard knowing that it will be used on a lower powered head? Just a thought. You know the thickness of the link is the same...but maybe not it's strength. You seem to have access to everything else...can you access a hardness test on the drive link? 
You have a very nice drive sprocket, with what looks like appropriate support...yet may still be peening the edges. Strange, unless the drive link of the lo-pro is as hard as frozen butter.

Without a hardness test, you could prove this theory but making an appropriate cut first with your setup. Assume lo-pro is good for say a 12" cross cut with low power. Try a 12" cross cut with high rpms but 1/2 throttle or something in order to mimic a low powered saw. See if you have any peening. It should only take one baby cookie if it's the drive sprocket (like you think). If it's the drive tab itself, it might be fine with low power and you'll cut the cookie and not have damaged the tang.


----------



## mtngun

Andrew96 said:


> Maybe the drive link is made to a different hardness standard knowing that it will be used on a lower powered head?


Santa hasn't dropped off a Rockwell hardness tester yet, but judging by how quickly files dulled while dressing the peened links, I'd say the drive links are plenty hard.

I inspected the bar last night, expecting to find massive damage. The grooves were only wallowed out at the very ends of the bar, still tight otherwise. The bar must have flexed to accommodate the peened links, like a snake swallowing a rat. No wonder the bar got so hot. :angry2:

Hopefully I'll have an update this evening. Decided to skip the Logosol spur and go straight to the modded 404 rim, because if the modded rim works, I'll want to sell the Logosol.

If the rim works, I'm still not out of the woods, because it remains to be seen if lo-pro will provide a decent service life on the 36" bar.


----------



## Kicker_92

Any thoughts on if an 8 pin sprockets would far any better being a larger diameter? You'd have more of the drive links engaged at a time.


----------



## mtngun

I'll be making an 8 pin rim this week, but my guess is that the 066 won't pull it well.


----------



## mtngun

Here is the 404 x 8 cut down to fit lo-pro. Every drive link meshes perfectly. Not much meat left on this ported rim, though






I experimented with annealing and then re-heat treating this 8 pin rim. That didn't go well. It only partially annealled. The machining operation still chewed up the carbide bit.

Then I heated to 1660 F and quenched it in oil. It doesn't seem that hard, I can still cut it with a file.

Hmmmm..... I may try again with a higher temperature. 

Meanwhile, this is good enough to test for speed and driver peening.


----------



## Brmorgan

mtngun said:


> I'll be making an 8 pin rim this week, but my guess is that the 066 won't pull it well.



Mine will pull it OK on an 8 in up to ~16-18" Douglas Fir. I don't file quite as aggressively in that case though, and it's a bit touchier to control in general. Do-able though.


----------



## Mad Professor

mtngun said:


> BTW, the Logosol spur is a Stihl part, #1122-640-2006. I dunno if you can order it at your Stihl dealer or how the Stihl price compares to the Logosol price.
> 
> 
> [.



Picco spur is not available in the USA from Stihl dealers, I had a good friend/dealer check

Maybe we could get Saw Troll to ship us a box full?

P.S. you can adapt an early 036 rim clutch to fit an 066 , but you'll be running the wimpy small clutch bearing. 

Andy/Lakeside described this a couple of years ago.


----------



## BobL

huskyhank said:


> The surface finish of the part looks plenty nice.
> 
> Annealing will cause more problems than it solves. These things look like investment castings and there's no telling what they are made of - how could you re-harden and know what you will get?


I agree, these type of materials probably need to be re-annealed and hardened in low Oxygen atmosphere so the metallurgy is probably screwed up no end by a regular annealing and hardening process



> Good luck with this and thanks for sharing the project.


+1

I don't think a 404 turn down is the way to go. Looking at you turned down 404 I can see one major flat spot plus a couple of others.





I've used the lo-pro and standard 3/8 sprocket on the 441 for 3 small logs and have not see the problem of drive peening you describe, could it be the 660 just has too much grunt for the 050 drivers?


----------



## mtngun

BobL said:


> Looking at you turned down 404 I can see one major flat spot plus a couple of others.


The mandrel used to hold the rims on the lathe is a very tight fit, the rims sometimes have to be tapped on and off the mandrel with a hammer. The flat spots you see are where I tapped the rim with the hammer. The rim is paper thin in that spot, and the half-annealed metal bends easily.

The flat spot should not effect function since the spokes do all the work, similar to a spur sprocket.

The 404 rims haven't been tested yet, though. Just as I was setting up to do a trial run, my chain adjuster snapped, and then it has snowed every day for over a week. Pic taken this morning.







> I've used the lo-pro and standard 3/8 sprocket on the 441 for 3 small logs and have not see the problem of drive peening you describe, could it be the 660 just has too much grunt for the 050 drivers?


Have you actually measured your drive links ? When you get back to Oz, please take a close look at them.

Stihl sells 660's set up with 3/8 x 0.050" chain, so you wouldn't think the narrow gage would be an issue. 

Thanks for your input. Keep me posted on your experiences with lo-pro.


----------



## Brmorgan

OK, tomorrow if I get time I'm going to grab my digital caliper and macro lens and take some pics and measurements of various chains, including non-LP because I'm sure I've seen more than a couple non-LP chains peened over noticeably. I always thought it was a normal part of chain wear.


----------



## Brmorgan

I took some pics and measurements of a few chains today.

First off is my old, original LP milling chain. Imagine my complete surprise when it turned out to be Stihl Picco upon further inspection! I'd never really looked closely at it before; I always thought it was Oregon for some reason. Either way, this is what it looks like:











There is some obvious mushrooming, but only on some of the drivers. Probably half are seemingly unaffected, and half of the rest not as badly as the ones in those photos. Even still, they measured between .053 - .055 at their worst. The backsides were measuring a perfect .050 with my caliper, so I know it was accurate. I'd estimate this chain has probably cut between 2000-3000 square feet of softwood. A lot of that was with severely insufficient oil too, when my old 066's oiler wasn't working properly last year. 

Here's the Carlton LP milling chain I got back in February. It's only got a handful of short passes in Pine and Juniper on it; probably about as much cutting as the LP chain you started out with here.






It's started to show some minor wear on the front of the drivers; most still measure a perfect .050" though, with some hitting .051" and a couple at .052.

I don't have any pictures of the Oregon 91VX I got at the same time as the Carlton. It's seen a lot more use though, milling up a couple big Douglas Fir logs along with a bunch of Cedar and some small random Birch. Not sure if it would matter, but it's been used exclusively on a 7-pin rim, while the Stihl Picco chain above was used almost entirely with an 8-pin. I say almost because I can't remember running it with a 7, but the probability exists that I did try it at some point back then.

Just for a comparison, here's my first ever milling chain, an Oregon 73 3/8" .063" semi-chisel - sorry, I can't keep Oregon's lettering scheme straight so I don't know what its designation is.






It's peened about as much as the Carlton, many show no wear and a few are only minor. Its drivers are a lot heavier to begin with though, so I would expect that. This chain has cut probably 2/3 the square footage of the Stihl LP chain, albeit while working a lot harder since this is a 33" chain used for the wider stuff.


----------



## mtngun

Thanks for the update on your LP chains, Brmorgan.  I appreciate it so much that I even forgive you for the wide images. 

It sounds like you are saying that you observe some peening on some of your LP chains, but it's not nearly as severe or as universal as the peening on my LP chains ?

I enhanced a couple of your photos. These two drivers look just like mine, except you only had a few damaged drivers, whereas the majority of my drivers were severely dinged.









The question is, why does my 066 seem to ding drivers more than your 066 ?

I haven't ruled out the nose sprocket. It seems to fit well after the mod, and even if it didn't fit well, _*IN THEORY*_ there should be very little stress on the chain at the nose sprocket, since it is just an idler. 

Not much more I can do until the replacement chain adjuster shows up and LP testing resumes.


----------



## Brmorgan

mtngun said:


> Thanks for the update on your LP chains, Brmorgan.  I appreciate it so much that I even forgive you for the wide images.
> 
> It sounds like you are saying that you observe some peening on some of your LP chains, but it's not nearly as severe or as universal as the peening on my LP chains ?
> 
> I enhanced a couple of your photos. These two drivers look just like mine, except you only had a few damaged drivers, whereas the majority of my drivers were severely dinged.
> 
> The question is, why does my 066 seem to ding drivers more than your 066 ?
> 
> I haven't ruled out the nose sprocket. It seems to fit well after the mod, and even if it didn't fit well, _*IN THEORY*_ there should be very little stress on the chain at the nose sprocket, since it is just an idler.
> 
> Not much more I can do until the replacement chain adjuster shows up and LP testing resumes.



That's another reason I'm interested to compare the Oregon chain that's presently mounted on the 066 & mill. It's been used exclusively with the brand-new 25" bar I bought a couple months back, whereas the Stihl chain above was used only with the old 25" that was originally on the $25 041AV I bought two years ago, and is pretty much worn out. It'll take an .063 chain now with no problems. The its nose sprocket was worn to where even an LP chain would sit down pretty tight on the nose of the bar; I believe I already posted a picture once of the LP riding pretty high on the new bar's nose sprocket, like 1/8" away from the rails or more at the tip.


----------



## mtngun

Mad Professor said:


> P.S. you can adapt an early 036 rim clutch to fit an 066 , but you'll be running the wimpy small clutch bearing.
> 
> Andy/Lakeside described this a couple of years ago.


You must have a good memory. 

From 2007:


Lakeside53 said:


> Sure you can put the small bearing and drum on a later 036/360 but you'd have to be nutz, or trying to dump one on ebay.
> 
> oh.. you think you have a real reason.. sorry.. first problem is finding a decent old drum... *They are no longer made.*


----------



## Mad Professor

mtngun said:


> You must have a good memory.
> 
> From 2007:



I'm pretty sure you can still get the small bearing clutch parts for 034/early 036 that have never been up graded to to newer 036 clutch. 

My 036 IPL lists the parts but it's an older PDF. 

I'll check next time I'm at the dealer. 

Also will compare an early 036 clutch to see if indeed it could be made to fit my 066. If it does, I'd be checking/greasing the bearing every couple of tankfuls until I determined it would hold up.


----------



## Mad Professor

Also found this one, another lakeside post:

http://www.arboristsite.com/showthread.php?t=58691&highlight=036+clutch+066

As you might now know, the 361 drum is in fact an 044/440 drum... and the depth IS different to an 034/036/360/029/039 (yep) etc. If you put the deep drum on a 361/044 etc you'll trash the oil pump/drive.


So.. yes, you can turn the 036 drum down (and re-notch) to fit a 361/044 etc. I've down that on similar drums before. Check the depth of the bearing support depth - you might need to skim that down from the inside also.


The bearing will not last. Check it and grease often... and try to find the steel cased version - not the plastic.

The orginal PDF on the 036 change is enclosed.


----------



## mtngun

Parts arrived for the 066 chain adjuster. Let the tests resume. 

A small pine log that has been sitting in my pile for a couple of years. It's punky and checked, but I may be able to get some shelving boards out of it. 066 is set up with the modded 404x7 rim and my oldest lo-pro chain.





Purty blue stained ponderosa pine.





Slabbed a 2nd pine log, producing 8 slabs total. 

The bar never got hot like it used to do when it was running peened drivers.

The chain continued to cut well so I never stopped to sharpen it.

The chain never sagged, so I never stopped to adjust the chain tension. At the end of the day, the chain tension was still perfect. 

Then I measured the drive links. Most were 0.049" - 0.051", without a hint of peening. I did find one that was 0.053", and the one right next to it was 0.056".  Not sure what was up with those two -- it's possible that I missed them when I was filing the damaged links. 

I'll continue to use the modded 404 rim and continue to monitor the drive links, but right now it's looking like the modded rim fixes the peening problem. 

Next step is to get out in the woods and puts some hours on the lo-pro and just see how it holds up.

Also, I'll keep trying to find a production-worthy method to turn the 404 rims on a lathe, but I'm not optimistic -- I'm afraid that any bit that's hard enough to cut the rim material will shatter when it gets hammered by the rim's spokes. A tool and cutter grinder would be ideal way to mod the rims, but I don't have one.

.


----------



## huskyhank

I think a tool post grinder will do it, even a homemade one like a die grinder clamped to the tool post. Or I bet you could send a couple dozen off to any grinding shop. How much are you reducing the diameter?


----------



## mtngun

huskyhank said:


> I think a tool post grinder will do it, even a homemade one like a die grinder clamped to the tool post. Or I bet you could send a couple dozen off to any grinding shop. How much are you reducing the diameter?


A 7 pin 404 starts out at 1.521" OD and gets turned down to 1.435", a 0.086" reduction. 

A tool post grinder could do it, but it would be very slow. I would guess something like 15 - 30 minutes per rim. And nobody likes to run a tool post grinder on their lathe. I sure don't.

My point being, if I had an easy, cost-effective way to mod the rims, I'd be glad to make them available to other CSM'ers. But, if it is something that requires a significant investment for outsourcing or equipment, then it's not in the cards. 

I haven't giving up on annealing yet. I'll try one more time, at a higher temperature.

I'll probably try some cermet bits, too, but I'm afraid they'll chip or shatter when they get pounded by the spokes.


----------



## Brmorgan

I'll ask my neighbor, who is the head machinist/fabricator at the big plywood mill here. He might have an idea or two; he's done some pretty bang-up work for me in the past. I think I have a spare old .404-7 rim somewhere that I could give him to play with.

Regarding the annealing, you may want to talk to fellow member TeddyScout, since he had a bunch of custom geardrive sprockets made for his 090G and 041G a while back. I do remember some discussion about heating/hardening etc., but not being a real metalhead myself (yet) a lot of it goes over my head.


----------



## mtngun

Just got some good info from -- who else ? -- Lakeside53. 

Stihl rims are actually made by Oregon.

Oregon makes the rims using the metal injection molding (MIM) process. It's basically a form of sintered powdered metal. 

Sintered powdered metal can be just about anything. It's not limited to conventional alloys. For example, they may blend in things like powdered tungsten or powdered cobalt to improve hardness and wear resistance. 

So -- knowing that, I think the annealing and heat treating option is out, since the rim is probably not a conventional tool steel that will respond to annealing and heat treating in a predictable manner.

I'm working on the cermet option now. Probably buy a few cheap cermet bits off the 'bay and give them a whirl. No guarantees.


----------



## Brmorgan

Yes, I do remember something about them being sintered. The word doesn't mean anything to me though other than that it's :censored: hard!

I know an angle grinder will chew away at a rim... Kinda inaccurate though!


----------



## BobL

Brmorgan said:


> Yes, I do remember something about them being sintered. The word doesn't mean anything to me though other than that it's :censored: hard!
> 
> I know an angle grinder will chew away at a rim... Kinda inaccurate though!



If they are sintered than means they are made from a metallic powder that is heated that fuses the powder together. If that is the case the they cannot be tempered in the conventional fashion


----------



## Kicker_92

Brmorgan said:


> I know an angle grinder will chew away at a rim... Kinda inaccurate though!



An angle grinder used while the part is spinning on a lathe can produce some surpringly accurate results. Just remember to measure often and use the finest flap sanding pad you can find..


----------



## BobL

*Lopro chain pics*

I just measured the driver link thicknesses on my 050 chain. 
My setup is 
a Stock 441 with 25" 050 GB bar.
Chain is GB R50S (Carlton N1C)
Standard 3/8 sprocket.
Chain has been used to cut up trailer load of firewood, and then used to mill about 2 dozen small slabs. There was a fair bit more stretching at the start than regular 3/8 chain.

Firstly comparing brand new chain (new drive link thicknesses are between 0.0480 and 0.0490") with the used chain.






There is evidence of some small amount of peening of the edges of the used drive links, maybe a bit like Brads. These drive links thicknesses range from 0.0505 to 0.0485 so the peening is minimal, maybe as the peening is generated it is being ground away by the bar groove.

This is about the most peening on any single drive link (this one was 0.0505").





About half of the links look reasonably clean like this (0.0485 to 0.0495")





Sprocket shows significant wear but it has also seen a fair bit of service with a pair of standard 3/8 chains (ie not a good idea). I'll keep using this sprocket with this chain but when I make up the next loop I will start with a brand new sprocket.




Using a used sprocket also might explain some of the tie wear.

Here's how it wraps around the sprocket.





Overall it looks like a bit more wear than I am used to for 3/8 chain but not sufficient to stop me using this combo at this stage.


----------



## mtngun

Thanks for the wonderful close-up pics, Bob. I wish I could take pics like that.

What I am looking at is how the drive links index on the spokes (or since we can't see the spokes, how they index in the ports). The gap between the port and the drive link changes as the lo-pro wraps around the 3/8 rim, since it does not fit well. 

The net result is that one or two links carry all the load, instead of spreading the load equally over 3 or 4 links. 





Here's my lo-pro on a 3/8 rim. Same pattern with the increasing gap.





Now here's one of the modded 404 rims with lo-pro, and the gap between the port and the drive link is 100% consistent, as it should be.





So why did my drive links peen like crazy, while your drive links seem unaffected ? A fair question. More CC ? Longer bar ? Different brand chain ?

All I know for sure is that I had serious peening on a virgin chain after only 4 minutes run time, and the modded rim seems to have eliminated the problem.

Thanks for the data. It's confusing, but that's real life.


----------



## mtngun

*cermet*

Tried the cermet bits tonight. 





But the bits chipped or eroded. I tried it several times with different speeds and feeds, was able to lessen the damage, but was not able to completely eliminate the damage. 





Eventually the rim diameter came out right, by that time I had smoked all the cutting edges on this particular bit.





The bit was $5, the rim was $5, so not counting my time, I've got $10 invested in the rim. Since I personally require only one rim a year, I can live with paying $10 for a rim (vs. $50+ for the Logosol spur). However, it's not a production worthy process that I could use to make rims for other people.


----------



## BobL

Good work mtngun. Hope it works out for you.


----------



## Brmorgan

mtngun said:


> So why did my drive links peen like crazy, while your drive links seem unaffected ? A fair question. More CC ? Longer bar ? Different brand chain ?
> 
> All I know for sure is that I had serious peening on a virgin chain after only 4 minutes run time, and the modded rim seems to have eliminated the problem.
> 
> Thanks for the data. It's confusing, but that's real life.



Buddy you gotta take it easy on those virgins...


----------



## srcarr52

*Machine Ideas*



mtngun said:


> Tried the cermet bits tonight.
> But the bits chipped or eroded. I tried it several times with different speeds and feeds, was able to lessen the damage, but was not able to completely eliminate the damage.



Just a few suggestions for mass production because it sounds like you're approaching the final answer to LP chain milling at a reasonable price.

Check your cutter height on your lathe. If the cutter is too low you'll chip the really hard inserts more often. I've always set the cutter slightly above the rotation center of the part. This keeps the tip of the cutter in compression and is less likely to chip off.

You can always rough the piece in with a grinder on the lathe and then finish with the cutter. This will save you on the cost of inserts.

Check with you local engine machine shop. They can chuck your already made mandrel in a crank grinder and take the material off in a couple of seconds. If they don't have a crank grinder an older Sioux style valve grinder has an X-Y table and can be used to grind down the outside diameter. But you'll have to turn down your mandrel to fit in the chuck.


----------



## mtngun

I'm not going to pursue the modification of 404 rims any further, unless I acquire new equipment. 

It was never seen as a for-profit venture, merely an opportunity to help my fellow CSM'ers, if I had a practical means to do so.

For my own use, a rim will last me a year, and I can live with destroying a $5 insert to make that rim. It's just that it's not a production worthy way to make the modified rims available to other people.


----------



## mtngun

New problem. As discussed in an earlier post, the sprocket teeth on my 3/8 x 0.050" Stihl bar were ground back to create a perfect fit with lo-pro. At the time, there was about 1/32" clearance between the side links and the modded bar nose, and it was working perfectly.

Lately the nose has been getting extremely hot. At first, I thought the bar bolt was pinching the sprocket bearing, but that issue was addressed, and now it is obvious that there is no longer any clearance between the side links and the nose. 





I don't know what caused the 1/32" clearance to disappear. I'll investigate and report back.


----------



## mtngun

A close up of the modded nose sprocket, showing severely deformed teeth. 

Also, note the sides of the nose are spread apart more than they should be.





The damaged nose sprocket does not spin freely. No doubt the bulged teeth are dragging inside the sprocket.

I don't understand what caused the damage to the teeth, or what caused the sides to spread apart, but I understand this isn't going to work. 

Later, I'll tear the sprocket apart and do an autopsy.

Until I have a solution, I have to put this nose sprocket out of service.


----------



## mtngun

*Inside of nose sprocket revealed ! ! !*

At last, we get to peek inside a sprocket nose tip. It's basically a very skinny roller bearing. The only moving parts are the itty bitty rollers and the sprocket itself. The 1" diameter disc in the center is solid and does not move. As long as our CSM bolts and clamps stay inside that 1" disc, we don't need to worry about pinching the moving parts.





Close up of the damage. Teeth are hammered, side of nose (that thing in the top half of the pic) is deeply grooved. 





Simulation of how lo-pro was riding on the damaged sprocket. For this pic, I set the side links right against the tip, similar to a hard nose, because that's how the chain was riding the last time I used it. As you can see, the drive links are not meshing with the sprocket teeth. That explains how the teeth got hammered.





Simulation of how lo-pro was riding on the modded tip before the damage occurred. For this pic, I left a slight gap between the side links and the tip. The drive links mesh pretty well. There is no obvious problem here. 





Simulation of how regular 3/8 meshes with the sprocket. Slight gap between side links and tip, and mesh looks good.





The autopsy results tell us that the sprocket bearing *was NOT pinched*, as originally believed.

So what went wrong ? 

Remember that in the beginning, I ground off the tips of the sprocket teeth to let the chain move closer to the sprocket and be supported by the drive links. The mod looked great and worked great -- for a while.

However, the tips of the teeth no longer speared the chain, like a normal sprocket nose. Without that spearing action, the chain was free to slide off the sprocket. Sure, the drive links were confined by the two sides of the tip, but those sides are pretty flexible, plus the drive links wore deeply into one side. The flexing and wear allowed the chain to slide deeper into the nose, which in turn screwed up the mesh and caused sprocket damage. Everything that happened, made everything else worse.

My current theory is that the root cause of the problem was a lack of side to side support for the chain, because the chain wasn't being speared by the modded sprocket tips.

In the future, I will not grind the sprocket teeth back. I may narrow them a bit, but it seems to be important that they "spear" the chain.

I've never had a chance to closely examine a proper lo-pro nose sprocket, so I don't know how they differ from a 3/8 sprocket.


----------



## Philbert

Great photos. This makes about 10 times I wish that I could rep you! (Somebody help me out here!)

I will use these in future chain saw classes.

Thanks.

Philbert


----------



## BobL

Real good work mtngun - I agree with your diagnosis 100%.

Now that you have that puppy apart what about turning up an annulus that turns the left overs into a roller nose. Flip the outside plates so the wear is on the outside. Don't worry about reriveting, it's going back onto a mill anyways - I'd just use some high tensile 6 mm allen bolts.

If you don't feel like doing it - you might might to send the bits to me and I will have a go - have to wait till august though till I get back to Oz.


----------



## mtngun

BobL, I gave the roller nose project serious thought, and decided I could buy a Logosol picco bar for less than what I would spend trying to make a roller nose, so if you want the old tip, you are welcome to it. 

The Stihl 3/8 replacement tip arrived today. Once again, the Stihl tip did not fit the lo-pro chain, not even close. For some reason, the sprocket teeth were unable to "spear" the lo-pro links. 

The Stihl sprocket teeth are around 0.059" thick. 





The space inside the links on Carlton 3/8" x 0.050" chain is 0.065"+ wide, plenty wide enough for the sprocket teeth. 

The space inside Carlton lo-pro links is around 0.055" - 0.056" wide, *NOT* wide enough for the sprocket teeth.

Using a safe-edge file, I filed the exposed portion of the sprocket teeth until they were about 0.052" thick. Now the teeth can "spear" the links. You can't see it in the pic, but the drive links are not meshing perfectly with the sprocket. I dunno if that is going to be a problem, but I don't have any better ideas at the moment, so I will try running it like this.


----------



## billstuewe

Mtngun, all my tips raise the chain obove the bar like in your picture and give me no problem. Try milling with it.


----------



## huskyhank

billstuewe said:


> Mtngun, all my tips raise the chain obove the bar like in your picture and give me no problem. Try milling with it.



Yes, that's how its supposed to be as far as I know.

Tried to rep you, mtngun, for all this good work but it won't let me.


----------



## BobL

Here's my 050 tip


----------



## mtngun

BobL, that looks like a decent fit. Thanks for the info. I'm guessing the sprocket teeth on your GB tip are much thinner than the sprocket on my Stihl tips ? 

I measured the sprocket thickness of some other brands:

-- 0.056" on a lightly used German Carlton 3/8"

-- 0.058" on an extremely worn Windsor 3/8"

-- 0.064" on a moderately worn Windsor 3/8"

All of those are too thick to "spear" lo-pro, unless modded.

It's been a long, bumpy road, but we are making progress at understanding lo-pro.


----------



## BobL

mtngun said:


> BobL, that looks like a decent fit. Thanks for the info. I'm guessing the sprocket teeth on your GB tip is much thinner than the sprocket on my Stihl tips ?



I guess so - I'd measure mine except I'm on the other side of the planet - closer to PNW than home. 



> It's been a long, bumpy road, but we are making progress at understanding lo-pro.


Mostly thanks to your determined efforts!


----------



## glennschumann

*Creating a source for a picco rim sprocket...*

I asked Grande Dog if they could source a picco replacement tip, and a picco rim sprocket for the larger saws, and add it to their product line... here is what he said...

http://www.arboristsite.com/showthread.php?t=140007

Thought it might have helped to ask...


----------



## glennschumann

Would it be possible to get a picco bar tip and transfer just the sprocket and bearings to a regular tip (remove and replace the rivets)/ Is there a picco sprocket that is large enough to fit in a regular tip?

Just a thought


----------



## mtngun

I'm thinking the only picco bars that Stihl sells are for little saws and the small bar tips probably won't fit big bars. 

Logosol would be the most like source, but they don't list picco tips on their website.


----------



## BobL

mtngun said:


> I'm thinking the only picco bars that Stihl sells are for little saws and the small bar tips probably won't fit big bars.
> 
> Logosol would be the most like source, but they don't list picco tips on their website.



The 050 GB bars are only about 3" wide.


----------



## Brmorgan

billstuewe said:


> Mtngun, all my tips raise the chain obove the bar like in your picture and give me no problem. Try milling with it.



That's what the nose sprocket is supposed to do, otherwise there's no advantage to a sprocket tip over a hardnose bar. If the chain is riding on the nose, the sprocket is worn out and the nose will soon spread and jam the chain.


----------



## mtngun

Well, I was headed to the woods first thing this morning, to resume testing injecta-sharp lo-pro with the revised 3/8" nose tip, but .... 

......on the way, someone flagged me down and asked for help. He was from Chicago, on vacation, and had been doing a little sightseeing yesterday afternoon, when he'd blown a tire, only to discover his new used car did not have a spare.  He spent the night in the car, listening to wolves howl (penned hybrid wolves, belonging to someone who lived nearby, but he assumed it was a pack of wild wolves ), and waiting to be rescued. I couldn't just leave him stranded there, so I had to cancel milling and take the guy to town to get a new tire. Oh, well, I've been "rescued" a few times myself, so I was glad to pay it back.

So, no milling pics today. Instead, you'll have to settle for a pic of the deer that's just outside my window as I type this.


----------



## BobL

mtngun said:


> Well, I was headed to the woods first thing this morning, to resume testing injecta-sharp lo-pro with the revised 3/8" nose tip, but ....
> 
> .
> .
> .
> Oh, well, I've been "rescued" a few times myself, so I was glad to pay it back.


On ya mtngun - that sort of stuff comes around if you 



> So, no milling pics today. Instead, you'll have to settle for a pic of the deer that's just outside my window as I type this.



Nice one!

This weekend we're doing a bit of tourist grade hiking in Banff national park.
Here is a few of my wildlife shots from our Lake Louise Hike this morning.
I recently bought a 70 - 200 F4 IS L series canon and it is gem for this sort of stuff.

I don't have a clue what these things are but they are cute and unusual to us








and this old fella was peaking over a cliff high above us for about half and hour - cool as a cucumber.




OK I guess we can call this non-native wildlife


----------



## mtngun

Awesome pics, Bob.  
First fellow is a squirrel, not sure the exact variety, but I call those "pine squirrels," because they live in our Western pines and firs.

Second fellow is a chipmunk. As with the squirrel, there might be a fancier name for that particular variety.

Your camera makes the mountain goat look very close. I've never had much luck getting close to a goat. They are usually on top of a cliff where they are difficult to approach.

The old goat in the last picture looks to be pretty high up. What was your elevation ? Did you walk there, or dirve ?

I take it no bears posed for the camera ?


----------



## Brmorgan

Nice pics Bob! Looks like a common Red Squirrel to me, though not quite as red as the ones out here tend to be. If you hang out in the mountains long enough, you'll see those bloody mountain goats in places that you would swear it should be impossible for any living creature but a bird to reach. The kicker is that their little ones are born up on the cliffs like that and they learn to step nimbly very quickly.

Those sure are nice lenses, eh? It'll come in very handy in that neck of the woods. My friend had one for a while, then upgraded to the f/2.8 before he switched over to Nikon completely.  I got to play around with it a bit. I like my Tokina 2.8 70-200 well enough, but it can't compete with the L-series.

Something you may be interested in seeing that's a short drive from Calgary is the "Big Rock" down just west of Okotoks on Highway 7. It's a huge rock (or rather a couple huge rocks that used to be one larger one) the size of a house out in the middle of nowhere, that was pushed there by the glaciers in the last ice age. I have some pictures of it somewhere from my last trip over there a few years back, but I can't find them right now.

Mtngun, that sucks on missing out on the milling, but as you said it's nice when you're on the receiving end of such help too. Good on ya.


----------



## BobL

Cheers guys - thanks for the info about the animals.

That lens sure is nice. I was going to get the F2.8 version but it's twice the weight of the F4, and when traveling - especially uphill, every oz of weight means something

We made it up past the tea house to the 6 glaciers plain behind Lake Louise which is at 6900 ft. It was an 8 mile round trip with a vertical gain of about 1200 ft. I don't mind walking such a distance, but its the vertical that gets me, especially coming down.

Well spotted about the goat mtngun - the goat image is a cropped one.

Here's the original.





But 15Mp, a monopod and a good lens with IS allows for a fair bit of cropping.
This is original Pixel for Pixel representation of the image.





And here is the first one I posted for comparative purposes.


----------



## mtngun

I'd never given the matter any thought, but Wiki says "pine squirrel" and "red squirrel" are two common names for the same critter.

Those squirrels are annoying when you are hunting big game. If a squirrel spots you, they make a loud squirrel noise to sound an alarm -- and they don't shut up, either.  

Squirrels in the eastern US are bigger and fatter. When I was growing up in Arkansas, squirrel was often on the menu.


----------



## mtngun

*No news is good news*

The thinned 3/8" nose performed well on its first day in the woods. There is no visible wear on the teeth, and the sprocket spins freely.

Note that I now tighten the locknut pretty snug, since there is no way it can pinch the 1" diameter sprocket bearing.


----------



## B_Turner

mtngun said:


> I posted this info on the chainsaw forum, but will add it here, too.
> 
> In the interest of science, knowledge, and truth, I cut off one side of a 3/8 rim sprocket so we could visually inspect how the drive links fit on the sprocket teeth.
> 
> The rim is a moderately well used Oregon 3/8-7. Made of hardened tool steel, it was tough to cut, however, no effort was spared for the benefit of my good friends on AS.
> 
> Showing new 3/8 Oregon chain. Since I have no way to apply torque, the drive links are not necessarily pulled tight against the sprocket teeth, however, you can see that if it were pulled tight, it would fit fairly well.
> 
> 
> 
> 
> 
> Showing new Oregon lo-pro. Only 2 drive links make positive contact with the sprocket teeth. The other drive links overshoot the teeth. Even though lo-pro has the same pitch as 3/8, a slightly larger rim diameter would be necessary to compensate for lo-pro's narrower side links (a picco rim does have a larger diameter, but I suspect it would be too large for lo-pro).
> 
> 
> 
> 
> 
> Showing used Carlton lo-pro. Again, only 2 drive links make positive contact while the others overshoot the sprocket teeth.
> 
> 
> 
> 
> 
> Well, I hate to admit it, but Saw Troll was half right.  The difference in the height of the side links does affect the way lo-pro fits a rim sprocket (dunno about how lo-pro fits on a 3/8 SPUR sprocket). The drive forces will be carried by only 2 drive links instead of the usual 3. That's more stress per tooth.
> 
> That said, it's not the end of the world. People have done it, are doing it, and will continue to do it until lo-pro rim sprockets are made available.



This is the first I have read this particular thread. I am loving these pics of the cutawayed sprocket as this is something I have thought alot about but didn't have a good way to do.

Bottom line is I wish more choices were available to use stihl picco sprockets as 1) they are bigger and I am guessing fit the picco chains well and 2) the picco chain IMO is a much better quality chain (much better chassis) than the other LP chains. (Although it has a wider kerf than some other LPs.


----------



## mtngun

I thought someone had mentioned that their GB 3/8 bar nose had fit lo-pro without modification, so I recently picked up a made-in-Oz GB Frostbite bar for my soon-to-be 'Kita 84cc mini-milling saw. Turns out the nose teeth are 0.062" thick, just like most other brands, and consequently won't fit between the lo-pro side links. 





Oh well, I'll thin the teeth so they do fit.


----------



## srcarr52

mtngun

Any updates on the lo-pro milling situation? How is the new spearing sprocket tip holding up?

I've been watching this thread for a while. opcorn:

Now I'm soon to start trying this combo on some precious Iowa Oak. I'm hoping the narrow kerf will help keep less in saw dust and more in my projects.

My plan is to keep the cutter bite to a minimum and regain the cut time with chains speed to produce a better finish. Right now I have a 32" GB Ti bar on my ported Husqvarna 288xp. Might be a little bit too much power so I'll leave the rakers high and resit the urge to push it hard. I might try to find a more sacrificial bar for the experiment.

What was the final diameter of the converted to lo-pro 8 pin 404 sprocket?


----------



## mtngun

My lo-pro milling saw exploded a piston last fall, so I haven't been able to use lo-pro since then.

The thinned nose sprocket was working fine and dandy.

Darn it, I'm sure I calculated the correct OD for an 8 pin lo-pro rim, but apparently I never posted it to this thread. The only way to know for sure is to draw it out in CAD. 

The one 8 pin rim that I did make measures 1.665" - 1.670". The measurements varied because the rim was a bit worse for wear after being used as a guinea pig in the heat treat experiments.


----------



## srcarr52

I'll give her a try at 1.670". I don't think the chain will notice 0.005" in diameter. 

I did pick up a used 32" power match so i can keep the GB bar nice. I'll let you know how it works out.


----------



## mtngun

Speed data for another 066 top end, as described on the chainsaw forum.

The usual 12 1/4" ponderosa pine cant, 7 pin rims, and a standard grind on WP milling chains.





lo-pro -- *0.95* inch/sec

3/8 -- *0.82* inch/sec

lo-pro was *16%* faster on this particular top end. I suspect it would pull an 8 pin on the pine cant, and maybe boost the lo-pro speed a bit, but I'll stick with the 7 pin for real world milling -- it's easier on the saw, especially on big logs.

For comparison, here's a summary of previous speed tests on 12 1/4" pine cants, 3/8" chain only (don't have the lo-pro data at my fingertips), the average of 3 tests over a 24" length:

0.64 inch/sec -- a popped & ported old-style 066BB that wasn't sealing very well.

0.62 inch/sec -- stock new-style NWP 066BB

0.59 inch/sec -- ported NWP 84cc Makita, 24" bar & cross-cut chain

0.57 inch/sec -- popped & ported OEM 066 that wasn't sealing very well.

0.45 inch/sec -- stock NWP 84cc Makita with no base gasket, 24" bar & cross-cut chain.

My pine cant has gotten drier and punkier since I began these tests, so no doubt speeds would be slower if the wood were more solid.


----------



## willbarryrec

Thanks for the info!


----------



## mtngun

As discussed in the Oldsaw's hook thread, a lo-pro chain ground 40/10/10 averaged* 1.24 *inch/sec, using the same 066 and the same pine cant as in post #176.

That's moving right along by CSM standards ! 

Let's see if we can summarize my lo-pro speed tests to date:

1.24 inch/sec -- 40/10/10 grind, hot rod 066 & 36" bar

0.95 inch/sec -- 60/10/10, hot rod 066 & 36" bar

0.81 inch/sec -- 60/10/10, stock new-style NWP 066BB

0.76 inch/sec -- 60/10/10, popped & ported 066BB that didn't seal well

0.73 inch/sec -- 60/10/10, popped & ported OEM 066 that didn't seal well

0.69 inch/sec -- 60/10/10, old-style 066BB that didn't seal well


----------



## mtngun

Finally broke one. This is my most used and most worn lo-pro chain. It spent most of its life on the 066 with a 36" bar. The teeth are nearing the end of their life.

At the time it broke, it was on the 84cc ported Dolkita, with a 24" bar, and was only a couple inches into a 18" log. I was running without an aux oiler because I'd forgot to bring it, dunno if that contributed to the break.





I patched it back together and will continue torture testing it, if it will cooperate.


----------



## Philbert

mtngun said:


> Finally broke one.


 
Doesn't look like that chain owes you much . . . .

Philbert


----------



## mtngun

Since the last update, the broke-then-mended lo-pro chain has been exercised a little more, and resharpened several times. It's definitely getting near the end of it's life, but I'll keep running it anyway, just to see how far I can take it.

When the teeth get this short, several problems arise.

For one thing, it seems to require more raker angle as the teeth wear. This morning I was running it with 8 degree raker angle, yet it didn't seem to want to bite. Since then I took the rakers down to 9 degrees, as shown in the picture, but haven't tested it in wood yet. 

Another problem is that it's tough to bring the grinding wheel down far enough, without grinding on the top of the drive link. This is also true when hand filing. The tops of the drive links have been ground/filed a bit, and that could have contributed to the broken chain incident.

Look at this picture, and you'll think "there's no way it'll work with that raker angle." :msp_rolleyes:


----------



## hamish

mtngun said:


> .
> 
> Another problem is that it's tough to bring the grinding wheel down far enough, without grinding on the top of the drive link. This is also true when hand filing. The tops of the drive links have been ground/filed a bit, and that could have contributed to the broken chain incident.
> 
> Look at this picture, and you'll think "there's no way it'll work with that raker angle." :msp_rolleyes:



Dan,

Your using a super jolly grider correct? Get a 3/32" cut off wheel disk (non depressed center) and mount it in place of the stone. The edges of the disk do permit some shaping, and you should get right down without hitting the drive link.

That 9 degree raker angle will work..............if some people can cut wood with the chain running backwards a sharp 9 degree'er will cut like a crazy beaver with real sharp teeth.

Jeremy


----------



## Philbert

mtngun said:


> Since the last update, the broke-then-mended lo-pro chain has been exercised a little more, and resharpened several times. It's definitely getting near the end of it's life, but I'll keep running it anyway, just to see how far I can take it.


 
Almost ready to mount that one on your bicycle . . . 

Philbert


----------



## bigjohn1895

hey all 
after reading this thread for the 3rd time i thought i would tell my little secret im a chainsaw carver and run lo pro 
on all my saws 45cc+ the bigest saw im running is a 84cc kita and i have removed all my chain adjusters after doing so i stopped breaking chains 
when the chain catches somthing hard the bar will slide back into the saw and the chain is saved all my chains are used till the cutters start to get riped off the chain 
on my kita i only use one bar nutt so the bar slides back easyer dont know if i need to or not but i feel better that way


----------



## hamish

bigjohn1895 said:


> hey all
> after reading this thread for the 3rd time i thought i would tell my little secret im a chainsaw carver and run lo pro
> on all my saws 45cc+ the bigest saw im running is a 84cc kita and i have removed all my chain adjusters after doing so i stopped breaking chains
> when the chain catches somthing hard the bar will slide back into the saw and the chain is saved all my chains are used till the cutters start to get riped off the chain
> on my kita i only use one bar nutt so the bar slides back easyer dont know if i need to or not but i feel better that way


 
Care to elaborate how the chain is saved the chain is thrown off the bar and impacted on the chain catcher and saw, not to mention potentially your body?

Chains thrown from a broken link are in most cases in much better shape than those thrown as a loop.


----------



## mtngun

This lo-pro chain is being retired because about half of the cutters have broke off. This is the chain that broke a drive link a while back, was repaired, and placed back into service. It's been resharpened about 4 times since the repair.

It spent most of its life as a 36" chain on an 066, then was shortened to 24" and powered by a ported 84cc Dolkita.


----------



## Philbert

mtngun said:


> This lo-pro chain is being retired because about half of the cutters have broke off. This is the chain that broke a drive link a while back, was repaired, and placed back into service.



R.I.P. after a long life of service, valiant chain!


----------



## gemniii

mtngun said:


> This lo-pro chain is being retired because about half of the cutters have broke off. This is the chain that broke a drive link a while back, was repaired, and placed back into service. It's been resharpened about 4 times since the repair.
> 
> It spent most of its life as a 36" chain on an 066, then was shortened to 24" and powered by a ported 84cc Dolkita.



RETIRED?
That chain has no rakers or cutters to speak of! Kill it and bury it!


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## Philbert

gemniii said:


> RETIRED?
> That chain has no rakers or cutters to speak of! Kill it and bury it!



Don't be so rash - Mtngun could still turn it over and scratch through the wood with the drive links . . .


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## sachsmo

mtngun said:


> Since the last update, the broke-then-mended lo-pro chain has been exercised a little more, and resharpened several times. It's definitely getting near the end of it's life, but I'll keep running it anyway, just to see how far I can take it.
> 
> When the teeth get this short, several problems arise.
> 
> For one thing, it seems to require more raker angle as the teeth wear. This morning I was running it with 8 degree raker angle, yet it didn't seem to want to bite. Since then I took the rakers down to 9 degrees, as shown in the picture, but haven't tested it in wood yet.
> 
> Another problem is that it's tough to bring the grinding wheel down far enough, without grinding on the top of the drive link. This is also true when hand filing. The tops of the drive links have been ground/filed a bit, and that could have contributed to the broken chain incident.
> 
> Look at this picture, and you'll think "there's no way it'll work with that raker angle." :msp_rolleyes:



No wonder the little teeth broke off, raker angle? I don't see no stinkin' rakers.


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## mtngun

sachsmo said:


> No wonder the little teeth broke off, raker angle? I don't see no stinkin' rakers.


As pictured, it was a little too grabby at the start of the cut, but worked fine once the bar was buried.


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## sachsmo

You _ARE_ the Eco-Logger.

Bet she cut pretty fast eh?


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## mad murdock

Any further updates on this mtngun? I have been checking out Bailey's offering of Logosol branded Stihl .050 milling bars and the picco chain to use with my CSM setup, and am intrigued by all your testing. I have been using the 3/8 Woodland Pro ripping chain, but can definately see the advantages to using picco with my setup. I am at the point where I need a new bar anyways for milling, and am seriously thinking about buying the B/C setup for the smaller chain to run on my 372XP powered mill. I do mill as well with my 075AV Stihl, equipped with .404 full skip chain, it is a beast in breaking the logs down quickly, but more recovery and less waste appeal to me as well. I will probably just outfit the Husky with the lopro setup, and leave the sthl alone. The guys at Bailey's told me that the bar will fit the Husky, as will the drive rim, so I think I will try it. I like the sound of 20-25% increase in milling speed too. Thank you for all your excellent lab testing and reporting on this subject for all of us poor old CSM'ers on here!


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## mtngun

mad murdock said:


> Any further updates on this mtngun? I have been checking out Bailey's offering of Logosol branded Stihl .050 milling bars and the picco chain to use with my CSM setup


Nothing new on my end.

I personally would use Woodland Pro lo-pro chain for half the cost of Stihl chain.


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## srcarr52

I just recently switch from a lo-pro setup on a 32" bar to a 36". I found a new old stock 36" Oregon bar in 0.050 and I now have almost 31 inch of usable cut when mounted on my 394XP. I've been using some Carlton chain but when I have to buy more I'll probably go with the Woodland Pro or the Oregon long cutter stuff and grind it the way I want it. I've been using a 5/45/0 grind and setting the rakers with a file-o-plate then -0.010". It's probably not as aggressive at mtngun's chains but they'll still grab very hard in a knot and pull down a ported 394XP with an 8 pin on it. I've found that the lo-pro chain holds up longer on the grind then regular 3/8. I got 60+ 10' cuts in a spruce with one chain last year until I hit a two screws, it kept cutting pretty fast but it wouldn't cut straight anymore. 

Here is a picture of me cutting some cedar at the Iowa GTG.


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## Mad Professor

Hi Folks,

Long time since I've been on this thread. Have had health and personal issues which have kept me away from the 066/logosol mill, in fact recovering from a surgery now..

Concerning sharpening Stihl picco chain, I've always used a Pferd file setup that takes down the rakers at the same time. Like Mt Gun I run my chains until the first cutter breaks off, but using the Pferd file I still have rakers left when the chain is wore out from sharpening, and the chain still cuts great. I keep the angles the same as they come on the PMX picco chain. I've not tried the Woodland lo pro milling chain but suspect the Pferd file would work well on it too.

Has anyone here used the picco/lo pro pin drive rim sprockets from Danzco? I purchased a lot of those in 7 pin for the 066 and have yet to use them. 

I'm hoping I'm well before the cherry logs I have start to rot.........I want to see if the DP muffler wakes up the 066 and give the Danzco sprockets a good testing.

Happy Milling

MP


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## BobL

Mad Professor said:


> Concerning sharpening Stihl picco chain, I've always used a Pferd file setup that takes down the rakers at the same time.



I can't tell from the diagrams of those things whether they progressively alter the raker depth with cutter length. Whether they do or not, given there is only one tool available for each chain size my guess like File-o-plates and the husky versions they will err on the side of conservatism and won't give sufficient raker angle to provide optimum cutting speed. Besides it is useful to be able to vary the raker angle and with cutting needs. Higher angles for softer narrower woods and lower for harder and wider.


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## Mad Professor

The rakers get maintained at a constant height/depth as you sharpen, relative to the cutters.

After several sharpenings the top of the rakers will start to become flat, before the next sharpening I dress the front of the rakers with a file . More of a radius , like a new chain, rather than a flat angle to the cutters. This is the same I do with my crosscut chains, after filing/grinding down the rakers to proper depth/height. 

The Pferd seems to give a good raker depth for my milling with PMX chain, 16-24" bars, 7-pin driver, 066 stihl, in hardwoods (ash, cherry, oak, maple). I might take them down a bit more if I was milling pine/conifers.

I have been hand filing my chains for > 35 years and can do my crosscut chains with just a file without any sort of guide. 

For the mill things are a bit more consistent using the Pferd. I plan on buying a 2nd Pferd so I do not have to flip the files when filing cutters on different sides of the chain.


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## BobL

Mad Professor said:


> The rakers get maintained at a constant height/depth as you sharpen, relative to the cutters.



If that is the case it won't be progressive. I had another look at the Pferd jig and my reading of it is that it works similar to the file-o-plate - which is . . . . er . . . semi-porogressive.

I wouldn't mind seeing a close up picture of it from above and an angle short from the side.

Thanks
Bob


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## Mad Professor

Bob,

As soon as I'm back on my feet I'll take some pictures of the Pferd and some of my "worn out" chains so you can see what the rakers/cutters look like when the first cutter finally snaps off.

Will also post some pictures of the Danzco 7-pin pin drive picco sprockets .

(Might take a week or two)

MP


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## BobL

No worries.


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## austringer

That was an exhaustive thread but quite informative however I am still unclear if its ok to use a standard oregon 3/8-8 ring sprocket with 63 PMX. I think what I got from it all was the bar sprocket tip may have been what has caused mtgun all the driver peening problems. That understood, I think I have done the right thing by filing my sprocket tip teeth narrower to accept the picco chain right? As far as the drive sprocket, I have ordered an oregon rim and drum set 3/8-8 for my 066. Hopefully there will be no issues with peening the chain. I do have a used .404-7 rim I could turn down though. And apparently Danzco may still sell picco rims for the 066! I think I will call them to be sure. Any additional input also welcome. I wont be doing a lot of milling, but I like to be geared up in case I get the urge and have a need.

Troy


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## srcarr52

austringer said:


> That was an exhaustive thread but quite informative however I am still unclear if its ok to use a standard oregon 3/8-8 ring sprocket with 63 PMX. I think what I got from it all was the bar sprocket tip may have been what has caused mtgun all the driver peening problems. That understood, I think I have done the right thing by filing my sprocket tip teeth narrower to accept the picco chain right? As far as the drive sprocket, I have ordered an oregon rim and drum set 3/8-8 for my 066. Hopefully there will be no issues with peening the chain. I do have a used .404-7 rim I could turn down though. And apparently Danzco may still sell picco rims for the 066! I think I will call them to be sure. Any additional input also welcome. I wont be doing a lot of milling, but I like to be geared up in case I get the urge and have a need.
> 
> Troy



You'll probably have peening issues. It wasn't the sprocket tip that caused the peening it was the drive sprocket no engaging more than one tooth. I've turned down a .404 8 pin to fit the picco/lo-pro chain and I haven't had an issue. 

If you're not going to mill a lot you may want to just run regular 3/8's.


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## xl185s

Hi,
My name is Christoph from Freiburg, Black Forrest, Germany.

i'm starting milling with a Stihl MS880 and a 30"-AlaskanMill.
After some trial with a MS660 and a modified 3/8-full chisel chain the need for more power and a narrower chain was strong.
So I bought a Stihl Rollomatic 36"-bar with .050 ,116 DL 63PMX chain and a 3/8-8 teeth rim.
After some modification of the studs, the tensioner bolt and the oil guide:



everything fitted well:




Everything?
Everything but the tip:




Without having knowlede of this thread I narrowed the teeth of the tip.

Some mild muffler mod:




For a first attempt everything worked well:




Everything?
After abot 10 cuts of 4ft the chain shows the well known peening on the drive links. :-(

I will now try to get a 404-7 teeth rim ged turned down to 1,435".
It seems that a rim for the 880 with 404 8teeth does not exist on earth... does anyone know a supplier?

Kind Regards from Black Forrest,
Christoph


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## srcarr52

xl185s said:


> Hi,
> My name is Christoph from Freiburg, Black Forrest, Germany.
> 
> i'm starting milling with a Stihl MS880 and a 30"-AlaskanMill.
> After some trial with a MS660 and a modified 3/8-full chisel chain the need for more power and a narrower chain was strong.
> So I bought a Stihl Rollomatic 36"-bar with .050 ,116 DL 63PMX chain and a 3/8-8 teeth rim.
> After some modification of the studs, the tensioner bolt and the oil guide:
> 
> After abot 10 cuts of 4ft the chain shows the well known peening on the drive links. :-(
> 
> I will now try to get a 404-7 teeth rim ged turned down to 1,435".
> It seems that a rim for the 880 with 404 8teeth does not exist on earth... does anyone know a supplier?
> 
> Kind Regards from Black Forrest,
> Christoph



Hi Christoph,

Welcome to the site. I've always wanted to be set loose with a chainsaw in the Black Forest. Driving from Kaiserslautern to Stuttgart I would just be in the edge of it and see the sustainable harvesting in action. 

You can still get .404 8 tooth rim drive sprockets in the US but most manufactures have stopped production. I do not think Oregon nor Stihl make them anymore. I'd be happy to get a couple for you and turn them down to the correct size. 

Grüße,
Shaun


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## xl185s

Hi Shaun,
Thank you for your warm welcome 

Getting the rims turned will be no problem fo me.
On the german Oregon-Homepage no rims for the 880 are shown at all.
The only ones I can find with 404-8teeth fit on the 660 etc.
Because the 880 has a bigger hub they won't fit on the 880.
Maybe the orignal Oregon part number would be help enough.

Unfortunately i'm not really involved in sustainable harvesting, except of making firewood for my home.
As you maybe know everything in Germany is a bit more regulated so getting "set loose" is more or less a fiction ;-)
I'm happy when I get my heap of logs near the forestal road sold by the regional forest official.

Kind Regards,

Christoph


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## srcarr52

xl185s said:


> Hi Shaun,
> Thank you for your warm welcome
> 
> Getting the rims turned will be no problem fo me.
> On the german Oregon-Homepage no rims for the 880 are shown at all.
> The only ones I can find with 404-8teeth fit on the 660 etc.
> Because the 880 has a bigger hub they won't fit on the 880.
> Maybe the orignal Oregon part number would be help enough.
> 
> Unfortunately i'm not really involved in sustainable harvesting, except of making firewood for my home.
> As you maybe know everything in Germany is a bit more regulated so getting "set loose" is more or less a fiction ;-)
> I'm happy when I get my heap of logs near the forestal road sold by the regional forest official.
> 
> Kind Regards,
> 
> Christoph



It's my understanding that the 880 runs the standard 7 spline rim drive sprocket or it came with a spur drive. If it has a rim drive setup it will have the same size rim as the 660. If it's a spur drive then you'll have to get a rim drive clutch drum. I don't think there is a larger hub than the standard 7 spline because with a .404 7 tooth sprocket the chain almost touches the clutch drum as is.


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## xl185s

Shaun,
you are right!
I just compared part numbers, where only the rim&drum sets of 660 and 880 are different because of the clutch drums.
The rims are both 3/6- 8T (0000 642 1216) and .404.- 7T (0000 642 1207) are the same.
From a mature chain and bar list I found 0000 642 1217 as the rim to buy.
If Stihl in Germany does'nt supply this rim, I think Oregon does ;-)
Many thanks,
Christoph


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## BobL

Back in 2010 I had an email discussion with Ed Danzer from Danzcoin (http://www.danzcoinc.com/index.html) who was in the process of making lopro rim sprockets but I never followed up to see if he had finished making them. Danzcoinc make a range of sprockets for harvester and racing chainsaws and I have a number of his higher count drive sprockets so I had every faith that the lopro sprocket would be a reliable product
If you follow up on this can you please report it here.

Because of possible chain stretch I was not going to use the lopro on my 880 but my 441 so I am interested to hear how the chain stretch on the 880?


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## xl185s

Good morning (10p.m.) ;-)

Good news: The .404 -8t rim (0000 642 1217) is deliverable in Germany.
The lp-chain had to be adjusted a little bit after each cut, but I can't say if was stretch or only thermal elongation.
The combination of much HP and additional friction of the peened drive links should be avoidable.
Has anyone ever tried to use a chain with reshaped drive links without a modified rim?
Maybe some cold hardening of the peened surface could bring an improvement?
E.g. like shot-peened connecting rods?

BobL, here (http://www.danzcoinc.com/html/large_oregon_7_spline_bore.html) is no dedicated 3/8LP-rim listed.

MtnGun: Many thanks for this research!
1.665" will be the modified diameter for 404 -8t rim ?
Regards,
Christoph


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## BobL

xl185s said:


> The lp-chain had to be adjusted a little bit after each cut, but I can't say if was stretch or only thermal elongation.


You should be able to identify if it is thermal expansion because if it is and you stop and let it cool down the chain will become very tight on the bar.
On my 441 I see both, but I only use this chain for very small logs (<18" in diameter) so it is hardly a fair test.



> as anyone ever tried to use a chain with reshaped drive links without a modified rim?


What do you mean by reshaped DLs?



> BobL, here (http://www.danzcoinc.com/html/large_oregon_7_spline_bore.html) is no dedicated 3/8LP-rim listed.


Yes I know these but Ed was going to make the LP drive sprockets as a special order


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## xl185s

BobL said:


> You should be able to identify if it is thermal expansion because if it is and you stop and let it cool down the chain will become very tight on the bar.
> On my 441 I see both, but I only use this chain for very small logs (<18" in diameter) so it is hardly a fair test.
> Thats clear, but I dismounted the bar after milling without watching after this aspects.
> Next time I will have an eye on this.
> 
> What do you mean by reshaped DLs?
> As Mtngun recogized also my DLs have been peened and became thicker.
> 
> With "reshaped" i meant they are filed or grinded to ther origin thickness again. Maybe I should have used "reapired" instead of "reshaped".
> My assumption in this question is, that the "hammered" surface of the DL reached a higher hardeness by this process.
> 
> Yes I know these but Ed was going to make the LP drive sprockets as a special order


I think turning down the here available .404 rim will be cheaper than importing the special order item.

Best Regards,
Christoph


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## BobL

> With "reshaped" i meant they are filed or grinded to ther origin thickness again. Maybe I should have used "reapired" instead of "reshaped".
> My assumption in this question is, that the "hammered" surface of the DL reached a higher hardeness by this process.


On my 441 I have also observed peening but I have not done anything about it as it is not severe.
The chain I have has been stretched so much it now jumps the 3/8 drive sprocket unless it is extra tight.
It sounds like I should start with a new loop and a turned down rim sprocket



> I think turning down the here available .404 rim will be cheaper than importing the special order item.


Almost certainly.


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## srcarr52

I run lo-pro on a 36" bar with a 8 pin modified .404 rim on a ported 394. The power proved to be too much for the carlton chain when I was cutting a full 31" of Iowa red oak and the chain broke. The drive links where not peened but they all where stretched and the back of one tore out. I hear the Stihl 63PMX is the strongest lo-pro chain on the market but it's hard to find in the states.


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## xl185s

You should get the 63PMX here or at your local Stihl dealer with the part number 3614 000 0114 (where 114 is the number of DLs).


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## xl185s

Here is a pic of the Stihl 63 PMX new (left) and after about 40ft of cutting with the 880 and a 3/8 rim (right).




As you can see, the unused surface is rather raw.
Also the peening is visible on the used DLs, combined with a better surface.

The unused DL are all thinner than 0.051", the used are all about 0.053" while the bar is about 0.055" which was less when it was new, as I try to remember.
So at this point in time no friction should occur.

I got my .404-8t rim, but unfortunately it has an open flange. This helps controlling the position of the DLs on the one hand, but on the other it gets only 0,06" of rim "meat" if turned down to 1.67".
Hope thats enough...;-)


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## srcarr52

xl185s said:


> Here is a pic of the Stihl 63 PMX new (left) and after about 40ft of cutting with the 880 and a 3/8 rim (right).
> 
> 
> 
> 
> As you can see, the unused surface is rather raw.
> Also the peening is visible on the used DLs, combined with a better surface.
> 
> The unused DL are all thinner than 0.051", the used are all about 0.053" while the bar is about 0.055" which was less when it was new, as I try to remember.
> So at this point in time no friction should occur.
> 
> I got my .404-8t rim, but unfortunately it has an open flange. This helps controlling the position of the DLs on the one hand, but on the other it gets only 0,06" of rim "meat" if turned down to 1.67".
> Hope thats enough...;-)



Mine is the same way my sprocket is and it's held up fine so far.


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## Mad Professor

Danzco did do a run of 3/8 LP rims for the 066 size clutch. I brought up a bunch, not sure if Ed ever did another run?.

They were pin style hardened drivers on the rims


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## xl185s

Mad Professor said:


> Danzco did do a run of 3/8 LP rims for the 066 size clutch. I brought up a bunch, not sure if Ed ever did another run?.
> 
> They were pin style hardened drivers on the rims


 
Message from Ed Danzer (Danzco):
_"We do make a *8 tooth large Oregon 7 spline for the Low Profile chain, it is part number DS0250 and costs $28.10* and can be sent Priority Mail or UPS. We do not do customs papers or pay any tariffs or duties, this is the importers tasks. We accept Visa and Master Card or we can send a PayPal link for payment. We charge a 5% processing fee for PayPal purchases.
We have changed the company name and are working on the new website so making a post linking to the Danzco, Inc . web site may become a dead link early next year. __http://6kproducts.com/__ This is the link the new website which currently sends you to the Danzco Website."_

So this may help you. I would have to pay additional German VAT and import fees even on a single item, so I solved the problem this way (Stihl .404-8T rim turned down to 1,670"):



Best Regards,
Christoph


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## BobL

I ordered a couple of 8 pin 404 sprockets before Xmas to copy what a couple of members have already done (i.e. turning the sprocket down to suit lopro chain) then we away for a couple of weeks and just got round to doing this and I though some of you might like to know about my experience.

Firstly I made up a chunky mandrel and turned a step in the mandrel so the front of the sprocket fits tightly over the step on the mandrel.





Then I turned an 8 mm thick cap and drilled and tapped the end of the mandrel so that the cap could be screwed down tightly onto the sprocket with an M8 allen bolt.




Using the cap in this manner easily held the sprocket while it was being turned and there was no slipping of the sprocket.

Like Mtngun I did wreck a TC lathe cutting tool tip, not when cutting the smooth part of the sprocket but when cutting the section where the the driver slots are located. Despite taking very light cuts the rapid on-off/chattering cutting at the slots eventually knocked the tips off the TC tip. Next time I will try a slightly more rounded tip. All up for the tip and the sprocket cost me $11 so I am OK with that.


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## mad murdock

Nice job on your custom tooling BobL. We have a tool post grinder at work, I think grinding to size will be better if it is that hard of steel.


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## Philbert

I know that most rims are cast. Could someone with a laser cutter make one up as a 3-piece laminated rim, spot welded together?

(Or maybe we need a 3D printer ?)

Philbert


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## BobL

Yeah I was going to take it out to my place of former employment and use the TPG but though I would have a crack at doing it I'n my shop.

Philbert, I suspect a laser cutter is what Danzcoinc use but they hard rivet theirs together.


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## Jimbo209

I'm going to drag this up as I think I'm getting a full roll of 63pm, 

IF a .404 nose can be squeezed onto a 3/8 .50 Bar then you could adjust both the nose and sprocket to a similar size. But I'm not sure about to compatibility, even if it's thicker not much of any would be in the wood anyway


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## Jimbo209

Philbert said:


> (Or maybe we need a 3D printer ?)
> 
> Philbert



That's more and more a option for things

Aha brainwave 084 parts and the like


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## srcarr52

Jimbo209 said:


> I'm going to drag this up as I think I'm getting a full roll of 63pm,
> 
> IF a .404 nose can be squeezed onto a 3/8 .50 Bar then you could adjust both the nose and sprocket to a similar size. But I'm not sure about to compatibility, even if it's thicker not much of any would be in the wood anyway



Earlier in this thread it showed how a regular 3/8's tip can be modified to work with lopro by thinning the tips of the sprocket so they properly spear into the chain links.


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## Jimbo209

Thanks for that  on phone lots of pages to read. Is it bad idea though or just a heap more work

Does regular 63pm work, not much weaker, I have a fair bit of standing pine lined up.
so it should be ok with the 660 then and maybe in fresh dropped bush hardwood lightly


----------

