This instructable teaches you to make a robotic hand that drums its fingers rythmically on the wood board that it is placed on using only one motor. The video below shows the finished result and can greatly help in your understanding of these instructions.
Step 1: Making the Fingers
The fingers are, in myn opinion, the most time consuming to make. You need to use a vice and a hammer to make each individual finger. The thumb is made from a few nuts and bolts curved together to make a thicker "finger". The following pictures guide you in the process of making the fingers.
Step 2: The Motor
The motor that I used was from an old Sony Walkman. I super-glued lego columns to the motor so that the column would spin. Four blocks on the column would rotate to press down on the finger levers, which are made from the wires of a coat hangar. The fingers are suspended with a long coat hangar wire, separated by washers. These allow rotation. The column is supported by a large nut and is kept centered by two metal plates that ared screwed into the board.