Those specs. are more like a baseline to give the most universal performance. . . .
+1 on setting up a 'standard' configuration for sharpening, which makes it easier for you. Although, my numbers are slightly different from GD's, I was taught, 'as a general rule':
30 degrees top plate/filing angle;
60 degrees grinder head angle
0 degrees vice tilt angle for semi-chisel chain
+/- 10 degrees vice tilt angle for full-chisel chain
0.025 inches for depth gauges
That said, if you consciously decide to choose other settings, or to experiment for different types of chains or different cutting situations, pick your own numbers. I have been told by a few Oregon reps that the exact angles are less important than getting every cutter sharp, and getting all of them on a chain the same. Most of our grinders are not that precise that we can tell if we are grinding at 29 or 32 degrees.
If I am grinding someone else's chain, I will follow w8ye's advice and try to 'copy' their existing angles by adjusting the grinder settings to match their best remaining cutter, unless they tell me that they want something specific. This way, I preserve their preferences, reduce sharpening time, and avoid excess chain loss and grinding wheel wear.
If you decide to use different settings for different chains, make yourself a little chart to keep next to your grinder for reference so that you don't have to go looking for the info each time.
Philbert
