A Timing pulley is a wheel on an axle or shaft that is designed to support movement and change of direction of a belt along its circumference.
Timing Pulleys are used in a variety of ways to lift loads, apply forces, and to transmit power. In nautical contexts, the assembly of wheel, axle, and supporting shell is referred to as a block.
Pulleys are also assembled as part of belt and chain drives in order to transmit power from one rotating shaft to another.
Timing pulleys offer excellent precision at a great price , Timing Pully used for RepRap, 3D Printer, CNC, Robotics and Automations etc.