Think I first saw this on reddit here. Thought it was a good concept so did some more digging.

Found v1 engineering after like 5 minutes on Google, cool crew pumping out CNC-adjacent open source projects, since dragging a ball across a sand pile is functionally the same thing as CNC/3dp/CoreXY, plus without a z axis they probably had a pretty clear path.

Pretty straight forward setup, 3 rails, 2 of which are being traveled by the 3d printed trucks via toothed belt which is fed through (2) cross corner motors. Middle arm can move up/down, left/right via motors going CW/CCW combinations. Middle arm then has magent which drags metal ball across the sand (baking soda)

Picture of the metal rods I had to cary 3 miles back from home depot because I didn’t have a working car at the time lol

Ball carrying system with ball seen in middle

Pic showing how three arms are mounted to bottom of table

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    ![IMG_521744F3-51DD-4402-953B-BC5EEABEF20B.jpeg](https://prod-files-secure.s3.us-west-2.amazonaws.com/286b54df-77c1-4797-839a-2a9cdff8e527/2c0c97e7-3473-4998-a5c0-752df02b3e3e/IMG_521744F3-51DD-4402-953B-BC5EEABEF20B.jpeg?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Content-Sha256=UNSIGNED-PAYLOAD&X-Amz-Credential=ASIAZI2LB466XSG6RSWB%2F20251222%2Fus-west-2%2Fs3%2Faws4_request&X-Amz-Date=20251222T024012Z&X-Amz-Expires=3600&X-Amz-Security-Token=IQoJb3JpZ2luX2VjECIaCXVzLXdlc3QtMiJGMEQCIG3MxsN6YLTAQ2MQoi7TYAQPU40gkLDaUwySrnMWXCgDAiBWhE4RTOtpNGfVkyFDEgBZvDFQhmI87zJkSVjAcKo1kyqIBAjr%2F%2F%2F%2F%2F%2F%2F%2F%2F%2F8BEAAaDDYzNzQyMzE4MzgwNSIMHDtjRds84%2BoWq2CrKtwDcQF0%2F1TTntNRpqGKspbDQJszbzRayQ92LwAsBf4oZv2F9nq7t3UpPaVb5hKg3jGlNYSYsksdlHHUav4WQl%2BLsMwNBo1n0BWZQNO5NWFsU94wRiD0flMH1OCoj4P%2BxYoJTPX%2BhwH0E3XoKMoaG1FUJEFQwOsvrtRmn9kPJpoS2YZOjAECxLzZJQZ%2FPFavsWbG3K%2Bg8bG2UNGtydjHSrCk8YB8D1Pz5Jn836qsRDpGKXvOEHyu3mQB3dz5OTXe4svtQap2PiFAyXWUzybHNwVItHCr0t%2Fc6EhFXdHm%2Fwvw4tCTHoxQIIt9SsSwbyCmVVyJV95QnDslsJx%2FL92b6u%2FFCQpaprjoR1Sv%2Fya2VjBi9T%2FaNj4bpx4IeWwwwGiu2CV5tlQv9qb%2BOdTlqnTjTytAhbHbP1QIXNHLu%2BwBFngr2LWhp4ZzKaGYl3DM3kFlu8lVeJgrhxlh5YaHUmC7ZfkWAsE8PTgP%2B6fvRX1xNsuFfdzVGnYs7kpL7fYN5G65NEx%2BOOscOHsjzOO89zxZm12ejHVGEhRC%2FMUjExnq3tUcjvtICpEXeaT9lDFXNCXpeW%2BwfeqWNPbZst1MGxA1wEub%2FDRUml1OM42lrdIhzcfAwTyB%2FVaSWktNJyTSpmwwr9KiygY6pgH31cuWRucVxyFLVlAMFxTzMFtUQrjLyDSXmy%2Bl80cZMVmb0XUFvVo0ryCyBNQXlfVQyMVatKP1gnr43NJf2ke3XMslOeqa%2BZrhPPJ%2FZe6o2inE%2BFGG5IxavQhqSzI0lqWsFlLD%2F95W%2BBO%2BmQLUTjBRbxTUb8qHUzerj8P4jBbTE%2FYrTEvegnWDWoU7tFYrhT4pDDLyslP1T25n54kLyMDpspFSkfLa&X-Amz-Signature=a039c3ce371593b353327cb0eca72559fee25cfacdb8ba0728b404d4a4cc0088&X-Amz-SignedHeaders=host&x-amz-checksum-mode=ENABLED&x-id=GetObject)

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    Final result, pretty neat, currently dissembled sitting in my closet until I find somewhere to live that is > 600 square feet.

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    TMC2209 Pen Laser V2 board with ESP32 on top

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