I constructed a prototype robot punching arm with a couple servos and an Arduino uno. The one servo acted as a shoulder and the other as an elbow. The wood pieces for the arms are about 6 inches long. The speed was obviously to slow and the torque was way to low. My idea is to make two stationary boxing robots. They will be humanoid and I will run the wires externally. I will also put a bread board that connects them to the Arduino on their face so that when they punch each other, they can disconnect wires, break transistors, etc, and get a "knockout". I am looking for opinions on how long you guys think that each segment of the arm should be, how many rpm's and torque should the motors have so that they are actually able to do some damage, and any other thoughts you guys might have. Once the project is completed, I will post the video of them fighting on youtube and post a link on SOR. Thanks for any help!