More design changes

After putting some more thought into our design, we've made a few more minor changes. We are now attaching the nylon rack to our machine by screwing it into a thin slab of aluminum which will then screw into the main arm. This is the method that was described in the manufacturing and assembly guide on ctools. We're also tinkering around with how we want to couple the rotating mounts to the track, which is proving to be more difficult than we imagined given the thin walls of the track.