# 17 boards



## mtngun (Sep 21, 2009)

My usual routine that I have posted many times before -- CSMing blowdowns that would otherwise rot. I'll just highlight what was different about today.

First off, we have been discussing what limits CSM cutting speed, power or chain or both ? BobL asked for a pic of my chain, but as I feared, my aging camera was not up to the task. This is the only decent picture and it doesn't reveal any useful detail. Just so you know I tried.






Today's victim, a 22" doug fir. Knotty, but straight. 





Log dogs. I have been dogsitting for a neighbor. To my surprise, the dogs behaved and didn't harass the elk that were bugling nearby.





Milling the 22" log with a 15 degree/FOP'd Bailey's ripping chain. At this width, I had to be pretty careful with the feed rate or else the 066BB would bog. The log yielded 9 boards, and by then, the chain cutting speed has slowed noticeably, so I switched to a NIB Bailey's ripping chain for the next log. 





The next log (no pic) was 17" at the butt end, quite dry, and the sapwood was a little punky. The heartwood was still solid, though. Cuts through this smaller, drier, softer log were noticeably faster, and less fuel was used per board. Was it faster because the log was smaller, drier, and softer, or because of the brand new chain ? Well, the only way to answer that question is to do timed cuts on a cant. Too many variables otherwise.

The smaller log yielded 8 boards, giving me 17 boards total. Considering how I didn't start milling till around noon, and my previous record was 20 boards in a full day, I was happy with today's results.





All day long, I kept asking myself, "if the saw had more power, would it cut faster in this particular cut ?" "Which chain cuts faster, 15 deg/FOP or 10 deg/standard raker ?" "Which chain bogs easier ?" 

In theory, the 15 deg/FOP should be more aggressive, and that's why I switched to it a while back.........but considering how my saw bogs easily, more aggressive may not be a good thing. Maybe my saw would maintain RPM's better with a less aggressive chain ? There is a lot to be said for keeping the RPM's in the saw's powerband.

Without timed comparisons on a cant, it's just speculation.

I will say that, if I had been milling blindfolded, I would not have been able to tell any difference between the two chains. If there is a difference, it is small. 

Regarding how much the chain "bites", I can easily manipulate the size of the chips by how hard and fast I push the mill. Babying the feed produces flour-like sawdust. A firm push yields chips up to 1/4" diameter, at least for a split second until the saw bogs. That gives the impression that the chain is capable of taking bigger bites, if only the saw could keep the revs up. 

Today's mechanical problems: The muffler cover bolts rattled loose, despite blue loctite. Yet another crack developed in the DP muffler cover. The muffler cover is fatigued and new cracks appear after every milling session. It has been welded several times. The "066" badge rattled off. 

Milling is hard on a saw, Anything that can crack, rattle loose, fall off, or wear out, will do so.


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## rmh3481 (Sep 21, 2009)

Always wanted to give this kind of saw milling a try. Thanks for posting the pics, they answer alot of questions.

Best wishes,
Bob


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## BobL (Sep 21, 2009)

mtngun said:


> First off, we have been discussing what limits CSM cutting speed, power or chain or both ? BobL asked for a pic of my chain, but as I feared, my aging camera was not up to the task. This is the only decent picture and it doesn't reveal any useful detail. Just so you know I tried.



Thanks for trying. I have blown up the cutter that is most in focus and here is what I see.





Apart from the gullet needing a bit of a tidy to help chip flow it looks pretty good. The rakers are classic FOP and could be just smoothed of between the FOP and original shape. The cutter hook does not look excessive, what size file are you using?

Next time you take chain pics see if you can hose the dust off and take pics from side on, top down and at the same angle as you did above. If you do it is daylight the camera will use automatically use a narrower aperture which makes more of the pic in focus.



> In theory, the 15 deg/FOP should be more aggressive, and that's why I switched to it a while back.........but considering how my saw bogs easily, more aggressive may not be a good thing. Maybe my saw would maintain RPM's better with a less aggressive chain ? There is a lot to be said for keeping the RPM's in the saw's powerband.


I assume the 15º angle is the top plate filing angle?
Top plate filing angle determines the sideways bite made by the chain which makes a slightly wider kerf and detracts from forward milling progress. The reason for having some (not zero) top plate angle is so the chain is not filed with even hint of negative top plate which can make so little kerf the chain can jam. A more significant angle is the top plate cutting angle which is file size and file placement dependent. As I said above your chain looks good so it's gotta be the saw.



> Without timed comparisons on a cant, it's just speculation.


Agree 100%



> Regarding how much the chain "bites", I can easily manipulate the size of the chips by how hard and fast I push the mill. Babying the feed produces flour-like sawdust.
> 
> 
> > Yeah this is definitely not right.
> ...


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## Ted J (Sep 21, 2009)

mtngun,
Since you are uploading your pics on photobucket, increase your pic resolution to as high as possible. Then take the pics as close as the camera will focus, Bob can then zoom in on those for a better view.

Ted


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## BobL (Sep 21, 2009)

Ted J said:


> mtngun,
> Since you are uploading your pics on photobucket, increase your pic resolution to as high as possible. Then take the pics as close as the camera will focus, Bob can then zoom in on those for a better view.
> 
> Ted



Good idea!


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## excess650 (Sep 21, 2009)

Have you checked the compression on that 066? What max, no load rpm are you tuned for? What elevation?

IMO, the 066 in good condition and proper tune shouldn't bog easily in 22" DF, so you're lacking power for some reason. I've milled DF, partially dry, up to 30" wide as that's the limit with my current bar.

My 066 milling saw has a Bailey's BB kit and is pretty strong. My backup saw is a 660 with stock sized piston and bore, but has had the squish tightened to increase compression. The 066BB is noticeably stronger despite the ports being smaller in the BB cylinder.

I put my Stihl RM chains (semi-chisel) on the grinder last week to get them evened up. I ground one at 15* and the other at 10*, and dressed the rakers. It cut more smoothly, and made bigger chips than previously, but cut even better when touched up with a file. My problem was more of a function of uneven cutter length rather than top plate angle.


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## mtngun (Sep 21, 2009)

Excess, as discussed on another of my threads, this particular BB kit has a low compression ratio, and only blows 125 psi despite using a custom base gasket to lower the squish to 0.020". I was milling at nearly 5000 feet altitude. The combination of low compression ratio and high altitude results in a wimpy saw.

BobL, I use a grinder, not a file. My cheapo grinder only adjusts for the top plate filing angle, not the side plate angle, nor the top plate cutting angle (I've asked Santa for a grinder upgrade, in addition to a tach, but Santa said not to expect much this Xmas). Despite its limitations, the cheapo grinder still does a better and more consistent job than I can do by hand filing.

Baileys ripping chain is 60/10/80/0.028", and calls for a 7/32" file. 

My modified chain is 60/15/??/FOP, and as you know, the FOP rakers are quite a bit more aggressive.

I may switch back to a standard 0.030" raker gage on ripping chain, at least until I get a more powerful saw. The FOP works great on my firewood saws, though.


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## Brmorgan (Sep 21, 2009)

3/8" low-profile @ .040 depth hums along quite nicely on my 066 in <16" wood, even with an 8-pin sprocket. Love that setup for slabbing cants. Bested only by a RipSaw, IMO. I only use it for slabbing too, that way it never gets exposed to garbage in the bark & doesn't need sharpening too often. Those cutters aren't very big!


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## LAndrews (Sep 22, 2009)

Hey - can y'all help out a new guy? FOP?


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## BobL (Sep 22, 2009)

LAndrews said:


> Hey - can y'all help out a new guy? FOP?



Carlton File-O-plate. A progressive raker height adjustment filing jig that increases the raker depth as the gullets get wider producing a constant cutting angle. Improves cutting speed considerably over a constant raker depth especially as the cutter length decreases.


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## mtngun (Sep 22, 2009)

Brmorgan said:


> 3/8" low-profile @ .040 depth hums along quite nicely on my 066 in <16" wood, even with an 8-pin sprocket. Love that setup for slabbing cants. Bested only by a RipSaw, IMO.



If my 0.063" bar ever wears out, I'll probably replace it with an 0.050" and give the lo-pro chain a whirl.


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## Brmorgan (Sep 23, 2009)

mtngun said:


> If my 0.063" bar ever wears out, I'll probably replace it with an 0.050" and give the lo-pro chain a whirl.



Yeah I'm in the same boat where my big Huskies are concerned - they're all either .058 or .063. I was hoping to get 24, 28, and 36" .050 bars to fit them for this summer but didn't have the cash after the sawmill shut down. It's nice because you can run regular chain OR low-pro in the .050 bars depending on the application. Sure, the drivers and straps on .050 _might_ wear a bit faster than .063, but I'm of the opinion that with milling use the cutter will most likely wear out long before, as long as the bar & chain are properly maintained and lubed.


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## BobL (Sep 23, 2009)

Brmorgan said:


> Yeah I'm in the same boat where my big Huskies are concerned - they're all either .058 or .063. I was hoping to get 24, 28, and 36" .050 bars to fit them for this summer but didn't have the cash after the sawmill shut down. It's nice because you can run regular chain OR low-pro in the .050 bars depending on the application. Sure, the drivers and straps on .050 _might_ wear a bit faster than .063, but I'm of the opinion that with milling use the cutter will most likely wear out long before, as long as the bar & chain are properly maintained and lubed.



It depends on the type of wood you are milling as well. I would love to run 050 LP for everything but the stress and resulting stretch on such a chain in big Aussie hardwoods would cause problems. My regular 3/8 chains can stretch and get hot enough to just fall off my 60" bars if I push them too much, especially at the start of the cut when the chain warms up real quick but the bar itself is still cool and so has not had enough of a chance to expand. Here is a post that calculates the typical thermal expansion of a cold chain and shows it is more than enough to fall off a long bar.

Here is a good post by Aggiewoodbutcher (whole thread is also worthe reading) about different size chains and cutting speeds and unfortunately having to stick to bigger chains on longer bars.


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## Brmorgan (Sep 23, 2009)

LOL, I can imagine it would stretch quite a bit with a 60" mill based on how much my 25" stretched! And no, I'm certainly not advising my setup be appropriate for all conditions - like cutting near-concrete, in your case.  But in this case, we live in (judging by pictures, anyway) virtually identical ecologies and tend to work with the same sizes and species of woods. Seriously, most of the pictures could have been taken on any number of hillsides a short drive from my house and nobody would know we lived a few hundred miles apart. Unless there's a Ponderosa involved - none of them up here; the northernmost one is about 75 miles to the south. Years ago there used to be a big sign next to the highway denoting the northern limit of their range - I guess it must have been a bit of a tourist location for folks who drove Hwy. 97 all the way north from California and saw ponderosas the whole way until that point. They'll grow fine here if you plant them, but they don't occur naturally.


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