Puck assembly

Description: A simple yet very precise component, the puck is composed of four main pieces: an aluminum body, a thin-section bearing, a hollowed ring of pulley stock and a steel flange. The thin section bearings included in this design are of 3 types for the purposes of testing the reliability of each. Four of the bearings are dry (no lubricant) stainless steel. Two are stainless steel with Ultra Dry Lightning (UDL) lubricant applied, which forms a molecular bond with the steel and so won't leak out of the bearing. Two are dry, full complement zirconium dioxide (ZrO2) bearings. Comparisons of price and performance of each of the bearings can be found in the Docs page under Performance Data. The pulley stock is press-fit to the puck body, trapping the bearing against a flange at the top of the puck. Wrapping the pulley stock with a different, offset group of teeth on the timing belt will change the angle the puck assumes with respect to its neighbor, and so this part is press-fit at a specified angle to the puck. Lastly, the steel flange along the bottom of the puck serves two purposes: it will guide the timing belt, preventing it from travelling along the pulley stock, and it will restrict the rotation angle of its puck. A set of tabs protruding from this flange will run into a fixed feature ("hard stop" detailed below) when it has reached the proper angle in either direction. The flange would be attached to the puck body with two ultra-low head screws.

Model showing locations of all eight puck assemblies in plate