Stronghold Drivetrain Review

[Kevin Sevcik]

Straight up WCD 6-wheel 8" pneumatic drivetrain. Center wheel was mounted in one of the Vex plastic bearing blocks, surrounded by two single speed clamping gearboxes. The gearbox axles had gears which drove another gear on the center wheel shaft for two reductions. Outer wheels were mounted on the WCP bearing blocks and driven by 9mm wide belts on 30 tooth Vex pulleys. Don't remember our final gear ratio, it was around for top-speed around 13-14 fps.

I can definitively state that driving 8" wheels with 9mm belts on 30 tooth pulleys works but is pretty marginal. 30 tooth is the biggest you can get and still slide under the CIM on one of the clamping gearboxes, so you're not going to get a lot of torque out of this drivetrain.

We used the metal bearing blocks for the outer wheels because we knew they'd get abuse. The plastic bearing block is the only one a documented C-C distance with the clamping gearbox, so we had to go with it in the middle. It was getting rather wobbly after 2 competitions of play.