Sure is coarse and rough and irritating, and it gets everywhere. But it can also be beautiful — drag a small ball through it in a controlled manner you can make some really pretty patterns. That’s precisely what this compact build from [Printerforge] does.
The build relies on an ESP32 as the brains of the operation. It employs small 28BYJ-48 motors to run the motion platform. These were chosen as they operate on 5 V, simplifying the build by allowing everything to run off a single power supply. Along with a bunch of 3D printed parts, the motors are assembled into motion system with linear rods and belts in a CoreXY layout, chosen for speed and precision. It’s charged with moving a small magnet to drag a ball bearing through the sand to draw patterns under the command of G-code generated with the Sandify tool.
We’ve seen some great sand table builds over the years. Some use polar coordinate systems, while others repurpose bits of 3D printers. If you’ve got a creative new way of doing it, don’t hesitate to let us know!
Nice. I wonder if anyone has designed a mechanism to lift and move the ball? That’d give a whole new range of art it could generate.
You’d probably need two separate motors and a arm above the ball to accomplish that.
Nice idea to have something to pick up the ball like a pen plotter does to increase the number of patterns. However this would lead to an aesthetic problem. The arm or mechanism would be in the way of the viewer. The fun of the sand plotter is watching the pattern magically appear. Gives a Zen experience. I don’t think an Ech-A-Sketch would have been as much fun with the drawing mechanism on top in the way. However, this is an idea that makes for a good hack and HAD article.
Ah, I hadn’t realised you could just use that arm to move the ball whilst in sand too. I envisaged the normal mechanism underneath with magnetic movement of the ball. Then an arm on the side that would only pop into view when the ball needed a lifted movement. That arm would then sod off back to where it came from.
A crazy idea: instead of that arm, a very precise solenoid under the table. Could be fixed at 45°. Then you’d only need to rotate it along the z axis. Then have the solenoid give the table an almighty (but precise) kick from underneath and have the ball airborne into the right position.
Crazier idea: integrate a levitation unit in the head that moves the ball so all the ‘magic’ can stay under the surface.
Totally. But we’re entering liquid nitrogen and superconductor zone here, aren’t we? There’s no other way to levitate the ball is there?
Get some ghosts to lift and move the ball?
I think I’ve seen wall clocks that could levitate such a ball unsupported in all directions, although I can’t remember their names. So I imagine you could do that, one way or another.
I bought my dad a levitating moon lamp. So it’s definitely possible.
Just add a Z-axis to raise and lower the table. Make sure the motion system gantry can move completely out of the way of the table. When you want to move the ball, first lift the table a bit to free the ball from the magnet, then park the gantry out of the way, lower the table below the gantry, move the gantry back where the ball is, raise the table again a little bit to attract the ball again, lower it so the ball can be moved without dragging any sand, and finally, figure out something to drop the ball again, before moving the gantry back out of the way and raising the table again.
For the gantry to be able to move both under and over the table, the table will need to be supported only from one side, and the motion system will need that side open. Fortunately, corexy allows this.
Better option is to use a magnetic ball and levitate it and reposition.