Most people imagine a robot having a humanoid form. One of the more interesting projects for the beginner is to model a finger. This has the advantages of taking the concepts learnt and expanding them to make a hand. One simple method is to use small tubes. These can be cut into three sections to represent the three sections of a finger. Each Joint in a finger has a movement of approximately 90 degrees, cannot be extended in the opposite direction, and has no lateral movement. The joints are normally linked together. It is very difficult to move the end joint on your finger without first moving the middle joint. We will ignore the joint connecting the finger to the hand and leave this for a later project. To control the movement, we will use a small servo motor connected to a horn. The horn connects to two wires, one that pulls the joint open, and one that closes it. These two wires run through the finger and connect to the end of the joint, one runs the shortest way through, this closes it, with the other straightening it. The finger is not allowed to hyper-extend by the design of the sections/