The Magic Sprocket.

This double sprocket allows the use of two runs of #25 series chain inside 2×1 box tubing for a perfect fit, prohibiting the chain from skipping off. Build your own chain-in-tube drive with your favorite wheels and the help of this magic sprocket.

This product was originally pioneered by Anthony Lapp from 221 Robotic Systems. Additionally, special thanks to Ty Tremblay and Team 319 for their insight and design advice on this product. This product builds upon this popular idea by adding chamfers to the teeth of the sprocket, as well as bosses on the faces to prevent the sprocket from rubbing the outer races of adjacent bearings.