Experimental 3D printing system uses rotation for multi-material printing

Maker Heinz has presented an unusual concept for 3D printing on Hackaday.io: an inverse SCARA printer that moves the print bed instead of the print head. The system is based on polar kinematic mechanics and combines two rotating discs that move the print bed along complex paths around the Z-axis. The resulting movement patterns not only look unusual, but also open up new approaches to multi-extrusion printing.

At the center of the structure is a vertical column along which the Z-axis is guided. The print bed consists of a rotating disc that can rotate both around its own axis and around the central column. This double rotation allows multiple extruders to be placed around the center point. The active extruder is simply moved under the desired tool by rotating the bed. This allows different materials or colors to be used without the need for a classic tool change system.

Since the extruder only moves along the Z-axis, its weight is less of a factor. In tests, the system also worked stably with a direct drive unit weighing around two kilograms with five filaments. Mechanically, the printer relies on common components: two GT2 toothed pulleys, ball bearings from a so-called lazy Susan, and 3D-printed structural parts. The print bed is made of fiberglass and is unheated. Small holes in the surface ensure that molten filament can penetrate and adhere.