Don,
The inside top plate angles are achieved with one filing, not two. The only "secret" in filing an un-modified chain is to know what you are trying to accomplish. Just don't push the file haphazardly with a hit and miss uneven type of strokes. Also it is essential to learn to file the same from either side. If one side is filed different from the other side, the chain will "run" and make curved cuts especially if the bar groove is worn over .005 wider or if one side of the bar rail is higher than the other. Uneven rails will also result in one side of the drive links to wear more. I prefer to run .058 gauge chain in a .063 groove on my racing saws.
If there is enough interest, I plan to cover chisel tooth filing and racing chain modification. I want to put it in the thread "Art Martin: will the real logger please stand up", if I can still find it to bring it up. I had a few more posts to complete in the old logging days catagory, as I saw it before I left the woods in 1963.
Art Martin
