[Kevin Sevcik]

Jason,

I don't think I specifically declared it above, but our arm design is fairly well inside BB's 35 ft-lb spec at about 8 ft-lbs, and we're still slowly failing our gearbox due to the shock loading I mentioned above. Yes, as an engineer I should've realized this was a possibility and demanded more than a 4:1 margin in the system. Still, BB's warning there doesn't really go nearly far enough. It's not that you have to limit the torque IF your motor-gearbox combo can exceed 35 ft-lbs. You have to limit torque if the load can exert more than 35 ft-lbs on the shaft. I think you could actually fail the gearboxes without a motor attached to them at all, in fact. So your only real option for using them safely as they come is to put a torque limiter on the output shaft and hope for the best.