A video by Primitive Technology demonstrates how to build a primitive cord drill and pump drill using just wood and stone. The end results can be used to start fires with friction or to drill holes in wood to create more advanced tools.
A cord drill consists of a shaft, a fly wheel and a piece of cord. The fly wheel is fitted onto the shaft so it sits about a third of the way from the bottom of the stick. The middle of the cord is then fixed to the top of the shaft. To use it the two ends of the cord are wrapped around the shaft, one end of the cord is held in one hand and the other end in the other hand. The ends of the cord are then pulled outwards