So I rocked a chain the other day and did quite a bit of filing to get it back sharp. I decided to measure my teeth with calipers and see how the length of each one compared. Chain is a Stihl 3/8 pitch, full chisel, 20" bar with 36 cutters (18 LH and 18RH cutters). All even numbers are LH and all odd numbers are RH Tooth number and length 1: .355 7: .350 13:.358 19: .348 25: .358 31: .352 2: .359 8: .365 14:.359 20:.350 26:.365 32: .359 3:.365 9. .354 15:.354 21:.362 27: .359 33:.355 4. .365 10: .368 16:.360 22:.351 28: .376 34:.354 5: .356 11:.355 17: .350 23: .362 29:.359 35; .354 6: .365 12: .375 18:.350 24:.359 30: .368 36:.371 Smallest tooth was .348 and longest was .376". The average for the LH cutters was .3622 and RH was .3559. It looks like for some reason i am a little more aggressive with the RH cutters. I picked the 12 longest teeth and filed them down to make the averages .3558 for LH and .3542 for RH with the smallest still .348 and the longest .360. Side note i used a 2 in 1 file so rakers should be filed appropriately. Just thought this was interesting stuff and wanted to report what i found to FHC.
If you use a progressive raker gauge, it doesn’t matter if those cutters are different lengths. That method of keeping them filed to the tooth will keep you cutting straight too.
Yeah i have heard that, and it makes sense. If each raker is set at lets say .020", each tooth should take off the same amount of wood regardless of length. I have also heard people say that the tooth length still matters. I just did this as i was curious as to how i filed one side vs the other and how much difference there would be. Answer was not that much difference between LH and RH anyways.
Thanks! I always count my strokes, but figured that i biased one side regardless. I probably wont change anything as i would just over compensate and make it worse lol.
If you are wanting every cutter the same length, I recommend a Timberline. I've had one for years. They make chains shave sharp and very very precise. Every tooth identical. I had a hard time focusing but you can see blue sky and green grass. Almost stropped like finish. So when I first started hoarding, I used the Husky guides to train myself to file. I got decent freehand after that, but I started to cut crooked. It was not a bar issue, it was my cutters on one side becoming shorter than the others. And the style raker gauge I was using was not progressive. So I bought the Timberline. Problem solved. I would hand file 2-3 times, then "true up" the chain with the Timberline. Did this till I learned to square file and I never looked back after.
Wow that thing is cool and it does have a great surface finish. How much does one of those cost and where is a good place to get them? Also, whats a progressive raker gauge? The one i have you just set on the adjacent tooth, and file the raker until it is level with the gauge. One tooth at a time. edit: Thanks for your help here wood wolverine.
Looking for vids to explain it and found this one. It's very good (not mine) so if you can find time, give it a watch. Buckin' Billy uses one too.
This takes a bit of reading , but it’s got some decent info . It does have a part that explains the difference between just setting the rakers at say ,.025 ,and setting them with a progressive gauge http://gepkolcsonzo.eu/wp-content/uploads/2012/01/complete-book.pdf
I was going to post the Carlton video explaining the use of the File-O-Plate but it puts importance on length of cutters, which just isn't necessary with the progressive style raker gauge. The info contained in that PDF is very good! Thanks for the share. The theory behind the progressive method is to increase the depth gauge setting as the cutter is filed back to compensate for the fact that as the leading edge crosses the hinge point of the rear rivet it will tip up less than when new and eventually will tip away from the wood. Now that the concept has been explained the question is how to do it! The difference between .045" and .027" is only .018". That .018" has a positive effect on the performance of the chain. Number starting 505 is the part number.
Thanks guys, this makes sense now. I didnt realize that the chain came partially out of the groove to make contact with the wood, so having the right angle (vs gap) makes sense now. That PDF was great, I read the entire thing.
