Messed up the tail gear mesh again...Help!

I messed the mesh up again, and I can't seem to get the right mesh now.
What is the best way to get the gears to mesh right?
How loose should the mesh be, should it be so loose that it makes a louder noise, like kind of a grinding sound, or should it be a smooth sound?
Thanks

I thought you were supposed to do that with the main motor gears, but the tail motor?

[rdn1153]

A quiet pinion/dive gear is a flag going up that it's too tight. If should be fairly audible. Err on the loose side.

There should be a slight amount of wink (slop) between the two around the entire circumference of the the gear, don't just check it in one spot. So when you are finished, there's wink at it's closest position and slop at it's furthest position.

Some slip in a thin piece of paper between the gear and pinion, tighten down the motor, the remove the paper. Still chick it around the entire gear, as you want to do this adjustment at it's narrowest gap.

Tight gear mesh will kill your power quickly, draw too much currnt, run hotter, burn the brushes, etc. etc. etc.

[jiri]

The "paper method" didn't work for me. I do it by an
eye. I think that a good mesh should not be too loose
such that it makes too much sounds. My test for a mesh
is that if I fix the movement of the motor gear, the other
wheel should still have little bit of free movement and
this I check around the whole wheel.

Jiri