[lurkingknight]

I start from the bevel checking the motor height and setting the bevel to start... usually as few shims as possible on the flat side of the bevel. then I check for play on just the bevel and how well it free spins.

Then I do the spur... always a minimum of the narrowest shim to start to give it better spin to start.. then maximize the tooth engagement while not being too close (as in resting on/come in contact with) to the actual gear faces. I check play again and see if either of the faces will make contact. Then repeat for the sector. The sector is sometimes tricky though, too many shims will fuck up the cutoff lever on one side... but too many shims on the other side I've had the tappet slip between the tappet cam and the gearbox shell during a compression jam that wasn't pretty.

When I spin the gears I will spin several times forwards and backwards with the gearbox oriented the way it will sit in the gun. Then I will spin again while the gearbox is on either side and check the play and interaction at rest when the gearbox is resting on either side and adjust accordingly. Sometimes maximum tooth contact doesn't give the best friction free roll so it's a balancing act. Just be sure to test the spinning with the shell screwed together... don't forget to hold the cutoff lever out of the way lol.

I've not had a gearset blow up on me yet.... bearing fly apart and spur plow into the gearbox shell yes... but no critical gear failure, and both my guns use SHS gears with questionable bevels.