We’ve competed assembly on one of the three Motor and Spool Sub-assemblies and we’ve discovered a few problems in the design.

1) The set screws are not holding onto the main shaft and are likely to be striped since the thread are made of plastic.

Solution: Drive a pin through the shaft instead of using set screws. Thank you Bob Stark for this idea.

2) The rubber that makes up the unwinding guide is too hard to form a gentle press against the spool’s channels and greatly increases the friction of the system

Solution: Remove unwinding guide, use motor to keep the wire on the spool by providing constant tension. This will come at a cost. The purpose of the winding guide is to stop the cable from jumping out of the channels when the system is powered off, thus we will need to unwind the system every time we are finished testing for the day.

3) The steel cable is getting damaged by the small bending radii in the design.

Solution: Replace steel cable with nylon fishing line.