Performance Evaluation of a 3D Printed Mirror Actuator : A Comparison with the James Webb Space Telescope

Abstract: This study aims to investigate the similarities in precision and performance between a James WebbSpace Telescope mirror actuator, the part controlling the motion of the primary mirror segments,and two 3D printed replicas. The two replicas were made from the plastics PLA and PETGand based on the designs of Zachary Tong. The plastics were examined concurrently and theresults were compared with simulations in COMSOL. The 3D printed parts were assembled and theresulting replicas were put in motion by an Arduino driven stepper motor. The result showed thatthe replica made from PLA had an average precision of 40 nm and the replica made from PETGhad an average precision of 32 nm. Compared to the James Webb Space Telescope actuator, bothreplicas were approximately one order of magnitude less accurate. The COMSOL simulations gavesimilar results. In conclusion, the study shows that the choice of material matters. The performanceof the James Webb Space Telescope actuator was more accurately emulated by the replica madefrom PETG than by the one made from PLA.