Shim Help

[MrEnDo]

Hi All,

New to teching shimming my gearbox don't know where I draw a line. My bevel gear I believe is shimmed right. It don't move up and down and moves when pushed. But my problem is should is spin completely around or just move slightly. I don't want to so it too tight. If I move .1mm it becomes lose and the bushing moves.

[Samurai]

It has to spin freely. If you have bushings, 2-3 spins, if you have bearings, then 5-10 full spins.

[SeniorSpaz87]

Bushings vs bearings means?...

[MrEnDo]

Cheers Samurai so it sounds like I over shimmed it.

 

What if the bushing turn with gears?

[Colonel Kurtz]

Its the hole the gears peg sits in, bushing is just a tube, bearings have small metal balls inside a ring to remove friction and provide better spin.

[SeniorSpaz87]

Ahh ok

[RR01]

It's really not worth shimming the top of the bevel gear, as it's meant to move slightly to ensure it meshes with the pinion on the motor. A small shim on the bottom end is OK and maybe another thin one on the top, but leave enough slack so that the bevel gear can move up and down about 1mm or so with both halves of the gearbox closed. When you refit everything and set the motor height you should take up the slack with how deep the motor sits in the pistol grip. Just don't tighten it too much, just set with the motor running on auto and adjust the screw on the base-plate until the gearbox spins freely and the motor isn't making any horrible noises. Smooth is good.

[Samurai]

The bushings turning with the gears is bad. It will wear the gearbox because the bushings are steel and the GB is pot metal. Glue the bushings in with loctite or superglue.