Hi Nevada Walrus and anyone else who may be interested, here`s a list of Oregon chains that require a 10 degree tilting vise to be sharpened properly. You`ll see that it is fairly long, and not just chisel chain:
25AP 1/4" Micro chisel
20BP, 21BP,22BP.325 Micro chisel
33,34,35LG .325 Chisel
33,34,35SL .325 Chisel
95VP .325 Micro chisel
72,73,73V 3/8" Chisel
72,73,75JG + LG 3/8" Chisel
72 + 73 JP, LP, + M**LP 3/8 Chisel
75LP, M75LP 3/8" Chisel
72,73,75 RD 3/8" Semi chisel Ripping
27, 27A .404 Micro chisel
27R, 27RA .404 Micro chisel Ripping
50,51,52L .404 Super Chisel
58,59CP .404 Micro Bit
58LG,59LG, JG .404 Chisel
59AA .404 Harvester
16H,18H .404 Micro Chisel Harvester
I agree with the others here who suggest that grinders are best left to truing up the cutters after multiple freehand filings or rocking out. A light touch is best, but you have to contact the tooth firmly enough to break down some of the abrasive or you get dull grains that lead to burnishing and burning. I also found compounds such as Kool Grind to interfere with good grinding(Thanks Walt), but chipmunks love the stuff. I disagree with John`s basic assumption that we file in one direction, we file inside out from both sides. This is a minor point indeed. With a reversable grinder, I believe you are better off grinding outside in, and any resultant burr forms on the inside of the tooth. The burr should be small enough to easily knock of with a few quick licks of the file, no matter what direction you grind in. I also somewhat disagree with Walt about attempting to center the wheel on the grinders we are talking about. If you are constantly grinding different chains for different customers, you may not notice the compounded error. But if you are repeatedly grinding your own chain so you watch it`s progression into being worn out, you will notice the cutters on one side getting shorter, unless you make an attempt to periodically re-center the vise. The centering device is crude, but it can be servicable. I took the socket head screws out of my grinders vises and replaced them with 3" 10X32 Thumbscrews and a knurled nut to keep them tight. I also take the dividing head from my machinists square and bisect each new wheel I get so I have a visual reference centerline to aid readjustment. I think it helps. Another tip is that the symettrical profile gauge you get with the grinder is useless for 3/8 pitch chain but it seems to work OK for .325 with a 60 degree head angle. For 3/8`s, I lay the head over to 50 degrees(Thanks Gypo and Walt) and profile the wheel so it is flat on the bottom to clear the depth guage as it comes in, and I have a larger than 7/64`s radius on the working face of the wheel. Probably a poor description and hard to visualize, but this is the only way I can come close to the right angles without too much hook. I also gently tickle the bottom of the topplate by pushing the grinder head into it. I didn`t talk about Silvey and Foley grinders in my previous post because I thought they were outside the price range rufcut was interested in. I didn`t get time to take pictures of the Oregon511A reversal mod, maybe later. I did get some pictures of a Jonsered Diesel chainsaw and a Sally Saw that my son and I came across while traverssing the Tug Hill Plateau and Adirondack foothills on Saturday. I`m at the "factory" now with out the means to down load the images, I`ll try later. Russ
