The angles high lighted with red, area circles in green, and height difference shown in blue are most important. Also, the foremost “working corner” or point is what grabs the chip and must be perfectly sharp, not blunted or rolled down. If the leading edge is blunt or rolled, or the outer chrome plating damaged, it must be ground or filed back to new metal.
Re: raker height - blue lines. Some say all cutters and rakers must be same height and length. Some say as long as each raker is set correctly to each cutter, it is ok.
It depends on how hard the wood is mostly. Very hard dry wood like I have here I keep them pretty even or I get chatter and vibration. I have cut softwood with sloppy hand filing all over the place and been fine.
Cutting straight - if I’m in the field and saw is cutting crooked, I eyeball the cutters. If they are not damaged, I take one file swipe off each raker on the opposite side of the way the saw is trying to turn. If it’s curving right, I swipe the left rakers. Generally gets it good enough until I can completely address the bar/chain.
