32P vs 0.8M gears
 

One day I switched my 32P spur gear to 0.8M but not the pinion.
I noticed 32P RCM pinion and 0.8M traxxas spur gear have more grinding noise than 0.8M RRP pinion and 0.8M spur gear.
32P vs 32P gears run smooth as silk but not 32P vs 0.8M.
I checked the mesh and they are both fine.
I never thought the tolerance between 32P and 0.8M can make such difference.

Shouldnt do, but there is this issue of 'pressure angles' too which complicates things. There was a thread about it recently, have a search around here & google it too, makes for a bit of a head scratcher to say the least...

If anyone finds it please post, I'd be curious to read this. Thank You.

.8 is 31.75 IIRC - Normally close enough its ok...

They have different pressure angles?
That means it works ok but it wears a little bit more until the both have the same pressure angels, right?

Sort of. The space between the teeth varies as the angle of the teeth changes. The spur will eventually wear in abit better, but I dont believe its anything to be unduelly worried about reallly.

I see. I just do not like the noise and it will come all over again as I change a different spur gear. Thank you, anyway.

I've run 32p pinions on Mod .8 spurs before and it ran just fine, nothing to worry about. There is a small difference but unless you run your mesh too tight it will work fine.