Originally Posted by
1Fastpede
anyone have any idea on screw size for motor using a big pinion and countersunk washers

Looks like an M3 FHCS (something like
91294A126 from McMaster Carr or
http://www.amainhobbies.com/product_...t-Head-Screw-6) and some self aligning washers (
http://www.amainhobbies.com/product_...er-Set-10-Gold). Haven't done this before....just me guessin'.