Testing The Twist at Roscomac

Chief operator Tim Osman had solved the issue while we were away. The guys had a new drill head machined and added new hoses to allow more coolant to be fired into the pen body during drilling. This meant that machining temperatures were much more stable and we were finally up and running.

It was now time to tackle the pens twist mechanism. We had already explored an M8 which is a standard screw thread as well as 16mm and 8mm thread pitches using SLA prototypes. Whilst they were successful, the material they were formed from had much more resistance. For the metal samples we decided to start with a 2.5mm pitch thread, which is quite tight. This was to ensure that the nib of the pen didn’t retract as you use the pen.

Our key findings were that the pitch of the thread easily resisted the force from the nib during use but also that brass on aluminium or brass on brass provided the least friction whilst twisting. We are now going to refine the thread pitch further so that less turns are needed to activate the pen. We will also make the threaded component solely out of brass to ensure the smoothest twist possible.

Massive thanks to Tim Bellringer, Tim Osman, Sean Keet and Dan Cornacchia.