Someone Might Care... Who Knows?

Jed

TreeHouser
Joined
Nov 2, 2010
Messages
4,291
Location
Snoqualmie, WA
Yeah just in case there were actually someone out there who might just possibly care, I decided to post this up.

I just figured out something small tonight. I used to talk to two different old-timers who round filed chisel chain, and they both told me the same thing though I could never figure out why. They said, "Always file up at a ten degree angle." "Why?" I would ask, "Since the manuals all say to just go across at a straight 90 degrees to the bar." Robert: "Jed... (eyes rolling) just do it. I've been doing this a really long time. Do you think I might know what I'm doin'?" Max: "Just the way I was taught to do it, and it's always worked out real good."

So anyway, I think that tonight, I just figured out why. When you sharpen without raming a wedge in the bottom of the bar, the drivers naturally rock over in the bar grove from the pressure of the pushing file(on a moderately worn-out guide bar) about ten degrees. One compensates for this with the ten degrees in the file. If you don't, the top-plate comes out with a more acute angle that the twenty-five or thirty degrees that you intended.

...... For those who might possibly care.
 
Cool Thread

I've always pulled up when filing, even to the point where I would over tighten the chain a bit to hold it in place.

I like a razor tooth...:drink:
 
I'll give it a try, I'm having real problems at the moment with sharpening.
I mean after 20 years of this game I reckon I can sharpen a saw, I'm no Jedi but up to 6 months ago I wouldn't embarrass myself.
Just lately I've been sharpening in the workshop in a vice with a spotlight and,as often as not, the results are just "ok"
I don't know if I'm getting crap chains or what.
 
I am not sure about this. That angle of 10 degrees up is still called for on a chain grinder, which clamps the chain in place.


The 10 degrees up isn't to compensate for chain rocking according to the Oregon rep I got to chat with a few years back. It's to maximize the cutting capability of the chain according to how the chain was engineered.
 
I think the ten up is to make certain the working corner of the tooth comes out right .If I'm correct Stihl just recently suggested it while Oregon for years used it .Because of the way Carlton was made it don't work so well with the ten up .
 
  • Thread Starter Thread Starter
  • #11
I'll give it a try, I'm having real problems at the moment with sharpening.
I mean after 20 years of this game I reckon I can sharpen a saw, I'm no Jedi but up to 6 months ago I wouldn't embarrass myself.
Just lately I've been sharpening in the workshop in a vice with a spotlight and,as often as not, the results are just "ok"
I don't know if I'm getting crap chains or what.

Actually, Mick: What Jim said! Could be the bar. As an arborist, I've got so much to learn from the timber-cutters. Those guys regularly "close" the rails on their bars using the little rolling-pin deal, and then re-grind them to a flat 90 on top, because those surfaces wear so much, depending on how you sharpen. Here's what I'm learning: the more the top-plate angle (as with 30* for round-grind) the harder the drivers push on the inside of the bar-grove when the chisel is planing the wood. This causes the outside of the drivers to wear on the inside of the groove (and especially the top part of the groove) so that the groove starts to become more of a "V" shape, than it's original "U" shape. This causes the drivers to rock-over harder when they're planing. This causes the "riders" to ride unevenly on the tops, so that the out-side of the rails wear unevenly, so that, after several chains on the same guide-bar, even the most perfect hand-filer will start to have inconsistencies. The ankle-bone's connected to the knee-bone.
 
I'm no tree man but I just keep the chain tight,bar in spec and use the factory angles with a Granberg file-0-joint or whatever it's called. I have time to play but you guys probably don't. Did have an ol timber butcher tell me to use the next size up file though. I used a 7/32 file for my .404 chain on my 3/8 chain instead of a 13/64 on one chain for a bit. Didn't notice much difference.
 
Actually, Mick: What Jim said! Could be the bar. As an arborist, I've got so much to learn from the timber-cutters. Those guys regularly "close" the rails on their bars using the little rolling-pin deal, and then re-grind them to a flat 90 on top, because those surfaces wear so much, depending on how you sharpen. Here's what I'm learning: the more the top-plate angle (as with 30* for round-grind) the harder the drivers push on the inside of the bar-grove when the chisel is planing the wood. This causes the outside of the drivers to wear on the inside of the groove (and especially the top part of the groove) so that the groove starts to become more of a "V" shape, than it's original "U" shape. This causes the drivers to rock-over harder when they're planing. This causes the "riders" to ride unevenly on the tops, so that the out-side of the rails wear unevenly, so that, after several chains on the same guide-bar, even the most perfect hand-filer will start to have inconsistencies. The ankle-bone's connected to the knee-bone.

I reckon you're right. I couldn't suddenly become crap at it. I'll change the bar on the 288/372
And yes arborists or whatever we call ourselves could learn a lot from timber guys.
 
I've found residential tree workers to be one step better then farmers at sharpening chain. Kind of odd.
 
IIRC, Stihl USED recommend the 10 degree angle on RS chain, then they stopped.

I'll have to look, maybe I'm full of shit on this one and have it bassackwards.......stay tuned.

Ed
 
About 40 years ago an old fellow told me the very same thing. However, he explained to me the reason, "If your file height is either too high or too low to begin with it can help keep the undercut of the top plate within spec much better." Ahh...

20 years later, after learning how to file square chain, that was all very elementary.
 
I have yet to get a chain very sharp![/QUOTE]
I feel your pain, its something I been working lately.
its so much easyer and safer with a sharp chain!!
:no:dull chains
 
Sawman, that Granberg file holder thing works great for me as long as I keep the bar closed and square like Jed said.
 
  • Thread Starter Thread Starter
  • #25
About 40 years ago an old fellow told me the very same thing. However, he explained to me the reason, "If your file height is either too high or too low to begin with it can help keep the undercut of the top plate within spec much better." Ahh...

20 years later, after learning how to file square chain, that was all very elementary.

O.k... so.... ah... How do you file square????? Man, I've all but given it up. My best luck so far has been with the triangle, because I can use one of the three flat sides to just barely graze the top of the tie-strap while the small corner of the file is in the corner of the chisel. I still can't really get good, consistent top plate angles though. My chains absolutely scream through the wood, but then when I get into bigger wood with a 32" bar all the way in, I just cuss myself--my cuts start curving just enough to not line up around the log. No fun.
 
Back
Top