Our Litter-Robot 4 was throwing motor torque faults. I found a reddit article which had a link to a replacement motor on amazon which is ½ the price of the original litter robot one ($55). However, the shaft on the amazon one is shorter and has a different key design. After ruining the original trying to manipulate it with a dremel, I decided to build my first 3D print design from scratch based on a gear generated with an online tool to give back to this great community!