I find the whole gullet thing confusing...or maybe I don't. When you file the hook the gullet rises up and eventially then from time to time you need to file the gullet back down.
1) So, why not use a file thats big enough to do the hook and also goes down into the gullet?
2) Is this because of the angle that it would cut the hook at? I think thats the answer but I want to be sure.
3) The file specified by the manufacturer dictates the proper hook angle?
4) So when you use a next size up file aren't you diminishing the effect of the cutting hook?
You have a few main angles when filing cutters. Some of the terms can get confusing:
The side plate cutting bevel angle is determined by the angle of the file, when viewed from above (typically 30°).
The top plate cutting bevel (typically 60°) is determined by the diameter of the file, and the height at which it is held.
The ‘hook’ (depth of side plate ’C’ profile) determines how much time the top plate edge has in the wood fibers before the side plate edges start to sever them. This affects how ‘grabby’ the chain will be, how much it ‘self-feeds’, etc. Deep hooks often result in shallower top plate cutting bevels, which will not hold up as long.
The gullet essentially cleans up the sides of the kerf in the wood, and helps to clear chips.
Then there is the depth gauge height, which determines how deep of a bite each cutter will take.
Once you understand this, you can use any size round, flat, triangular, or trapezoidal shaped files to achieve your desired results. You can use rotary stones or shaped grinding wheels.
Using the ‘recommended’ diameter file, in an appropriate file guide, makes this stuff much easier.
The key thing is knowing what you want your cutters to look like when finished. Kind of like Mr. Miyagi in ‘The Karate Kid’.
Philbert
