Self Balancing Egg ( Columbus Egg )

cults3d

This egg always stands vertically once released. It contains a 5/8" or 16mm metal bearing ball at its bottom, which shifts the center of gravity near its wide base. I printed it in vertical orientation with material support only from the printing bed (no internal support). Once the internal cylinder was completed, I paused the print, dropped in the ball, and added glue from a hot gun. Then I un-paused the print. When printing finished, I cleaned up the bottom with an X-Acto knife and sand foam sponge to round it out. Next, I balanced the egg by placing it on a flat surface, observing its orientation, and sanding the side that was too high (the egg tilts away from the high side). PLA material, 0.2mm layer thickness, with a material cooling fan on at 30mm/s speed, support from the printing bed only (not inside the egg). If you want to adjust the design or dimensions, load the .scad file and generate an STL using OpenScad (free, open-source software available for all major operating systems). I attempted to mark it as customizable but Thingiverse timed out too early.