[SgtMillhouse648]

Originally Posted by CraigHickman

Ah. It's close enough to not need tensioning, and may even be changed to use kevlar belting if I ever end up making the thing.

Ok, good to know, If you do plan on making it sometime, 648 used a similar setup as far as the individual crab modules go. The whole yoke was extremely tight clearance. The bevel gear cleared the tread on the wheel by about 1/16", and we had a real PITA trying to tighten up the chain. What we ended up doing though worked pretty slick once it was set. In our setup, the bearings which you have on the yokes, were actually on the wheels, and the sprocket was bolted to the wheel. This let us mill a slot where you currently have your bearings, and attach a small threaded block to which had a bolt and jamb nut in it. The axle was milled flat at each end, and the bolt was tightened down equally onto the axle on each side until the chain tightened. It worked real slick. 1625 had a similar crab setup, but used a small cam tightener to tighten the chain. Needless to say, some sort of chain tightening device is a necessity if it is to see the floor.

Malhon