Brmorgan
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Went into work at 6 am today but the other shift had blown up the 200hp motor on my top chipping head in the canter, so I got sent back home and took the opportunity to mill some D Fir 2X12s for my brother to build a staircase out of. Tried a few different combinations today, and it led me to the following-
In "Chainsaw Lumbermaking", Will Malloff has a suggestion for a different way to sharpen milling chain. He says to put one thickness of a matchbook in between the file and the file holder guide (the universal flat type) in order to change the hook angle of the tooth. The cardboard makes the file sit a bit lower from the top of the tooth, and it results in a lower angle and a more narrow edge which in theory should shear the wood fiber more easily. I've been trying it lately and it does seem to cut more smoothly, and maybe a bit faster though I haven't timed it. And FWIW, I filed the 25" 3/8 skip bucking chain on my 660 this way, and it hauls azz now. Took a bit of getting used to because I almost had to hold it back until it was in the cut good, otherwise the chain wanted to bind because it was so aggressive. But it cut FAST buried in D Fir.
So far, the best combination I've found for milling is 3/8 full comp filed like this on an 8-tooth sprocket for the 20-28" bars, or a 7 tooth for the 33" bar in harder wood like birch. I tried .325 9-tooth (can't find an 8-tooth locally) on a 33" bar on my 395 but was not convinced it was any faster. However, that was with its original sharpening, and I have yet to file it with this modified method so I'll be trying that soon. I do, however, use a 20" .325 full-comp 9-tooth filed this way on the 660 to rip boards under 12" from cants, or to do small logs. It's really fast for this, makes a nice smooth cut, and I can push quite hard on it before it starts to bog out.
I no longer lower the tooth angle down to 0-10°, or buy dedicated ripping chain, as I've found that standard full-comp full-chisel chain cuts noticeably faster, and since I end up planing over 90% of what I cut, smoothness (within reason) isn't a mitigating factor. Even the rough-cut beams I used for my deck were cut like this and look comparable to the output of a circular or band mill, which is acceptable for me for that use.
So has anybody else tried filing their chains this way? Of course all you guys with your fancy-schmancy grinders have more options, but I'd still be interested in hearing opinions on angles. The only downside I've found so far to filing this way is that the edge dulls considerably faster. However unless I hit something fairly major (hit some gritty bark today :censored
, the teeth usually only need a light stroke or two every hour or so of cutting.
Also, I do have an old ripping chain that I broke a couple teeth off of when I hit a spike, and I think I might try modifying that one to be similar to the Granberg ripping chain. Just a question though - does Granberg's pattern go (left scorer) - (right scorer) - (left cutter) - (right cutter) OR (left scorer) - (right scorer) - (left cutter) - (right scorer) - (left scorer) - (right cutter)? Sorry if that's confusing. Thanks guys.
In "Chainsaw Lumbermaking", Will Malloff has a suggestion for a different way to sharpen milling chain. He says to put one thickness of a matchbook in between the file and the file holder guide (the universal flat type) in order to change the hook angle of the tooth. The cardboard makes the file sit a bit lower from the top of the tooth, and it results in a lower angle and a more narrow edge which in theory should shear the wood fiber more easily. I've been trying it lately and it does seem to cut more smoothly, and maybe a bit faster though I haven't timed it. And FWIW, I filed the 25" 3/8 skip bucking chain on my 660 this way, and it hauls azz now. Took a bit of getting used to because I almost had to hold it back until it was in the cut good, otherwise the chain wanted to bind because it was so aggressive. But it cut FAST buried in D Fir.
So far, the best combination I've found for milling is 3/8 full comp filed like this on an 8-tooth sprocket for the 20-28" bars, or a 7 tooth for the 33" bar in harder wood like birch. I tried .325 9-tooth (can't find an 8-tooth locally) on a 33" bar on my 395 but was not convinced it was any faster. However, that was with its original sharpening, and I have yet to file it with this modified method so I'll be trying that soon. I do, however, use a 20" .325 full-comp 9-tooth filed this way on the 660 to rip boards under 12" from cants, or to do small logs. It's really fast for this, makes a nice smooth cut, and I can push quite hard on it before it starts to bog out.
I no longer lower the tooth angle down to 0-10°, or buy dedicated ripping chain, as I've found that standard full-comp full-chisel chain cuts noticeably faster, and since I end up planing over 90% of what I cut, smoothness (within reason) isn't a mitigating factor. Even the rough-cut beams I used for my deck were cut like this and look comparable to the output of a circular or band mill, which is acceptable for me for that use.
So has anybody else tried filing their chains this way? Of course all you guys with your fancy-schmancy grinders have more options, but I'd still be interested in hearing opinions on angles. The only downside I've found so far to filing this way is that the edge dulls considerably faster. However unless I hit something fairly major (hit some gritty bark today :censored
, the teeth usually only need a light stroke or two every hour or so of cutting.Also, I do have an old ripping chain that I broke a couple teeth off of when I hit a spike, and I think I might try modifying that one to be similar to the Granberg ripping chain. Just a question though - does Granberg's pattern go (left scorer) - (right scorer) - (left cutter) - (right cutter) OR (left scorer) - (right scorer) - (left cutter) - (right scorer) - (left scorer) - (right cutter)? Sorry if that's confusing. Thanks guys.
