Difficulties and Lessons Learned

While building the mechanism, I accidentally tore one of the gears (the blue gear in the image above and to the right).  While I was still able to finish the device by gluing both halves of the gear directly to the shaft, the torn gear does result in some skipping and unsteady movement.  I likely could have avoided tearing the gear by using less glue, which makes the paper softer and easier to rip.