This is a side view of the drive system. Note the position of the drive chain tensioner, which engages a large number of teeth on the main drive sprocket. This is a closeup of the drive tensioner, designed by crew member Jon Foreman. The main drive sprocket is on the left, and the tensioning idler, which spins freely on its own needle bearing, is on the right. The angled bracket on the tensioner goes down and mounts to the base.
Tension is maintained by the horizontal jack screw at the far right.
It pulls the idler away from the drive sprocket and two screws help secure it in place. Many people just use the two screws to keep tension, but the jack screw is the key to keeping your chains from loosening up over time. This is a side view of the same drive system with the wheels installed. The black clamp in the middle of the picture secured a drive battery to the frame during the testing phase. In fact, during battle, the frame would flex when I fired the hammer.