Rhombot

thingiverse

Rhombot 0.3 alpha is a printable XYZ stage based on 3 chains of rhombus shapes. This early alpha version is essentially a rough sketch of the idea; see an animation on YouTube for how it's intended to work. The Rhombot can be used with Makerbot motors, electronics, and extruders, with all parts buildable in a Makerbot or within itself. Notably, this innovative stage design features no rods, belts, pulleys, nuts, threads, screws (other than motor screws), sarrus hinges, moving towers or motors. Instead, its XYZ motors and extruder motor are all fixed, making it suitable for use with large, heavy motors - an advantage when printing such motors in the future. The build platform has a unique Z-coordinate system that uses sine functions of the NEMA17 stepper motor under the light blue panel, and the dark blue arm's and purple arm's motors for X and Y respectively. This requires modifying Skeinforge to account for the additional sine input. The Rhombot's build volume is large enough to print all its own parts, as demonstrated in an animation showing it building four of its own parts and a cube large enough to hold any of them. However, the actual build volume is an odd shape. A printed Rhombot on a ZCorporation ZPrinter 650 shows exceptional rigidity and smooth hinge movement despite the sandpaper-like surface. Replacement of wooden toothpick hinge pins with aluminum rod segments is planned for future builds. The next step is to build this in plastic, which will be stronger but may encounter panel bending and twisting issues. To print, follow instructions to print everything in the stl_to_print.zip file, using 3mm diameter hinge pins. Hinge connections are determined by engraved numbers on each piece, indicating build direction and facing orientation for seamless assembly.