A sand table project based on a corexy platform with an ESP32 controller running FluidNC. I built this a year ago and figured maybe it's worth documenting while I remember some of the details. Of course this is inspired by the wonderful Sisyphus Table by B Shapiro
My table is based upon the STLs from the excellent Sand Table and documentation by Ravi Dudhagra.
I used printed the plastic bits in black ABS on my Tiny-M printer.
The table itself is a 1/2" of melamine coated MDF with a thin piece of white fabric to minimize noise with baking soda as the media. This is reasonably quiet when the steel ball is rolling over it (especially while moving slowly).
I used different software as I had a spare ESP32 based board by Bart Dring from his Tindie project Pen Plotter Controller Kit for ESP32 & TMC2130. The initial software for this board was esp32-grbl, but this was outdated and I instead used FluidNC.
The biggest benifit to FluidNC is that you use a pre-compiled one from the GitHub project and create a configuration file (config.yaml) that matches your hardware.
FW version: FluidNC v3.4.1
WebUI version: 2.1b72
Another great thing about FluidNC and the ESP32 controller is that it can be used over WiFi with a simple web browser.
-turn on the machine, bring up the Web GUI and home the machine
-optionally load up a new image to the SD card via the Web GUI
-use the Web GUI to draw an image
For the colored LEDs, I used an Arduino I had laying around running a repetative pattern that works well enough. A future upgrade could replace this with a WiFi based board.
This is all built into a 2'x2'x2' coffee table that I found on Craigslist for $25. I used black spray paint on the backside of the glass top to frame the area of the sandtable.
Create Patterns at Sandify
Sand Table and documentation by Ravi Dudhagra
Sisyphus Table by Shapiro
Always Tinkering
ZenXY v2
I have the X dimension reversed and if I draw text it gets reversed. I've not bothered to figure out how to fix it as I really don't want to mess with what is working.
The LEDs are always running as the Arduino program is in a loop. Ideally, I'd put in a Web Controled LED program, but hey, don't mess with what's working.
One drawback of a non-circular sand table is that the patterns need to be scaled for the machine dimensions. With the Sisyphus round tables, all the patterns will work as they are based on a unit circle.
