When My dad and I were looking for motors, we ended up
getting two 24 volt NPC motors and the gear boxes that went with
them. I made an aluminum housing so the motors are on top of each
other. The motors go through a reduction with the gear box and
then go through another reduction with a single step chain drive.
I got rid of the V-belts because my tank required to much torque to use
them. My tracks compensated for the V-belts because they are the
intralox conveyor belts with the smooth surface. If the tank gets
stuck, the tracks free spin on the ground. It turns great and
runs fast for a heavy tank. I used a 10 tooth #35 roller
chain sprocket. The chain ran to a 32 tooth sprocket from small
parts catalogue.
In the pictures I removed the logic coil battery because I am
working on a turret servo which is powered off of it. I have also
removed the receiver and receiver battery. The black marks on the
tracks are slices of 3M tape that are used for traction on steps so
people don't slip and fall.