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.

 

[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.

 

[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

 

[BobL]

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

 

[Philbert]

Great post - really helpful photos.

Thanks.

Philbert

 

[mtngun]

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.

 

[SilverBox]

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.

 

[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?

 

[mtngun]

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.

 

[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.

 

[BobL]

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.

 

[Rooshooter]

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.

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.

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.

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.

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

 

[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" .

 

[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

 

[Philbert]

Good Photos. Thanks.

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

 

[mtngun]

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.

 

[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.

 

[Rooshooter]

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

 

[mtngun]

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.

 

[mtngun]

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.