Robot Hand Week 3

By: Micheal Hartman on May 8, 2013

So it has been a little while since I have had the chance to work on my robotic hand, but this past week I have made a leap in a working prototype. I built a working test bed that I could test the electronics working with the mechanical parts. I began working on making more fingers for my hand attaching all but the pinky. Now I can test the motor moving multiple fingers. By attaching the tendons to the fingers and motor armature I can test opening and closing. Unfortunately I ran into an issue with the motor not having enough torque to account for the additional fingers. To compensate for the added tension and to create more torque I attempted to create a gearbox. The gearbox required to much power even before I attached the tendons. I ended up smoking the control board.

I’ve been taking apart cheap remote controlled cars and using the remote to act as my control system. I still was figuring out the best way to gear down my motor when one of our members, Chris, found a motor with a built in gearbox that would prove to be what I needed. When I got back to the lab Chris handed me the motor and asked if I thought this would work. I said I think this is exactly what I needed, but I needed to test it at a level I knew wouldn’t fry another control board. So I hooked the power generator up set it to the 4.5volts. That the remote control cars ran on. The motor turned but the real test I would try to stop the  motor by grabbing into it and seeing if I could stop it, but I couldn’t  so it passed the power and torque test. Modifying the armature for the new motor I strung the the tendons to the fingers and armature, attached the old battery box from the remote control car back to the control board wiring it to the new motor. With batteries in the battery holder and the power switch on it was time to test this wirelessly controlled hand.