Closed-Loop Control of a 3D Printer Gantry

Abstract

The use of closed-loop control to improve performance in gantry robots is a well-established technology, but adding the necessary sensors and computational hardware to low-cost 3D printer gantries has been generally thought to either be too expensive due to the cost of the hardware or ineffective in offering real practical performance improvements. This thesis develops and evaluates low-cost closed-loop controllers for the X and Y axes of a 3D printer gantry, for some trajectories demonstrating path-following precision improvements greater than 40%. The ability to detect and correct for skipped steps increases reliability and allows for more aggressive tuning of motion parameters; time savings of up to 25% are seen by doubling acceleration rate. The platform developed seeks to increase awareness of the potential for the integration of closed-loop control into existing open source designs.