A great deal of automated machines follow the same operating principles that CNC mills have been using for several decades. 3D printers, laser cutters, plasma cutters, pen plotters, waterjet machines, industrial sewing machines, and others all work in the same way, with stepper motors or servo motors moving a tool along rails in two or more axes. If you understand how these work, you can build all kinds of interesting machines. Simon Sörensen, of the RCLifeOn YouTube channel, has taken that knowledge and applied it to this amazing CNC sand art machine that can draw patterns using magnets.
Sörensen’s project was inspired by the fantastic Sisyphus “Kinetic Art Table” that successfully launched through Kickstarter a few years ago. That machine contained a large sandbox with a metal ball bearing that was rolled around by a magnet under the table. As the ball moves around, it creates patterns in the sand like a Japanese karesansui garden. Previously-drawn patterns can be “erased” by simply drawing back over them with a spiral. Sörensen’s machine works in exactly the same way and is capable of producing really beautiful sand drawings. It does all of that automatically and can be programmed to cycle through a variety of patterns for endless amusement.
The circular table that holds the sand was constructed from cheap particle board, which Sörensen stained a dark brown to dress it up a bit. The outer wall was made using a series of flat laser-cut pieces of wood that were then covered with the kind of thick, rough rope that one would expect to see on a pirate ship. Underneath the table there is a simple two-axis CNC machine that was built using common 3D printer components (salvaged from a Creality CR-10S) like lengths of aluminum extrusion that act as linear rails. The power supply and a generic RAMPS controller board are also mounted underneath the table.
A strong magnet is mounted in place of the CNC machine’s toolhead. That magnet drags around a ball bearing on top of the table. Sörensen had to experiment a lot to find a surface material and type of sand that yielded clean lines and a minimal amount of noise. He ended up settling on a mirror covered in the finest grit sand that he could find. Finally, a string of RGB LEDs were mounted on the inside of the table’s walls to bathe the sand art in pleasing light. It may work exactly like the Sisyphus table, but Sörensen’s DIY version is still mesmerizing to watch.