At Ceromaze, the main body was connected to the face shield with a tubular arm. At each transition, a radial joint needed to be integrally designed. This joint needed to have set positions that it could “click” into which was to be done through the use of a detent-interference configuration.
I developed a python script to calculate the number and geometry of the detents based on a variety of factors (size, holding load, minimum articulation angle, etc.). Using this data, the joint was designed in Solidworks and printed with the company’s multi-jet 3D printer.
Of course, the primary concern with a joint like this (beyond fulfilling the minimum engineering requirements) is fatigue. Calculating this was trivial, but validation required an experimental jig. I then developed a gear train to supply the appropriate torque and radial speed to cycle the prototype joint. This was driven by a stepper motor and built out of PLA from our FFM 3D printer.
This final device is pictured below, though was not able to be run during my tenure.
