Please look at this thread if you are designing your own gearbox for the drill motor:
http://www.chiefdelphi.com/forums/sh...ad.php?t=24181
The bottom line is that I have designed my gearbox with a 0.006" increase in the center distance due to the oversized pinion, but please read the thread for details.
I am using a 56 tooth gear to mate with the 15 tooth gear. My standard center distance would be 24.85mm and I am using 25.00mm (0.015mm ~ 0.006").
Also,
If you plan on using the gear from the drill motor then you need to get your mating gear at
www.pic-design.com. Beware that these gears take at least 2 weeks for delivery. I ordered mine on 1/15 and still have not received them.
I hope this helps.
-Paul