The finished screwdriver passed all tests! We sat at a comfortable 170rpm and were able to drive the stated 20mm screw into MDF. The above video shows us pushing the screwdrivers limits, attempting to drive a wider and longer screw with no pilot hole!
A key learning point from this project is to allow even more time and resources for things to go wrong! Distaster struck on the night before submission when our gearbox was unable to move- increasing the gap between meshing teeth and a quick re-print solved that.
A mere hour before submission, the driver froze up again due to the central spur gear friction welding onto the carrier plate. Without any spares, I thought on my feet and carefully seperated them using a scalpel. I then drilled out the area to avoid further contact.
Times like these are invaluable for developing problem solving ability, and to better prepare for future deadlines!