Below is the a picture of the completed 3D SLS printer, clearly showing the outer aluminum frame and paneling designs. The SLS printer is then composed of three main mechanical sub-assemblies explained below.
XY Gantry Mechanism
Traditional XY gantry stages which make use of lead-screws will fix one axis to the other, resulting in different drive system dynamics which can contribute to part error. However, our gantry system uses a Capstan Roller mechanism which truly isolates the 2 axes while moving. A linear coupling will slide along the intersection of the two capstan rollers, providing the 2D translational motion for the Laser Module.
Special thanks to Ilam Moyer’s Foamcore CNC Machine for the inspiration for the gantry system.
Chocolate Powder Distribution
The food-safe Teflon Chocolate Power Distribution system allows for the 3D printing process to occur automatically, in successive layers. With the start of each new layer, the over-sized feed bed lifts one layer thickness (<1mm), and the print bed lowers one layer thickness. A Teflon sweeper arm transfers the next layer’s powder from the feed bed, to the print bed, ready to be sintered in the next layer of printing.
Z-axis Powder Beds
The z-axis for the 3D printer is accomplished using a linear stepper motor coupled to a lead-screw. This assembly provides remarkably accurate Z-axis resolution, at 4000 [steps/inch], allowing for precise control of the chocolate layer thickness.