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=ASIAZI2LB466Y4PYLVKB%2F20251222%2Fus-west-2%2Fs3%2Faws4_request&X-Amz-Date=20251222T005014Z&X-Amz-Expires=3600&X-Amz-Security-Token=IQoJb3JpZ2luX2VjEB8aCXVzLXdlc3QtMiJGMEQCIHFWJG%2BSuUSR9dNnv4cdGxL6AdkB0kgnUKrKrwRfacopAiAJrMC%2F1CdDMLYodI2rrCzv7%2BzjmU3mEL%2FZJ0FuAjNsziqIBAjo%2F%2F%2F%2F%2F%2F%2F%2F%2F%2F8BEAAaDDYzNzQyMzE4MzgwNSIMDMxHYLOMnidPmvlKKtwDerGtZU3OtT3cMj1uLOT5NlRuWftFeto8rc1Nz6Ucnpjayl2HqQ4jL%2B3JEZf7hFFGLMr5sYB8q77ZWt5e5E5uu%2B1ctrqsj%2Ba9x9IOp1Ptm2dAGd9e0fx0qpdiTQFanlTiJdCh4lSDQ3ReAX7b3oag%2Fo6EZKVwWOeMrJjB5DX400XhusYnLP7q9HW6pxvk2hNrJrOCqPPgejOeuykll6kNHzT8FWEtvBhvvCq9Uky%2F5v6p2i7gjN9p8Ej2cDZUTbIk5W%2BPDiAW%2BWt8eYVSlEf%2BXvKMETJ9WnJ3Xpucjfi1XZuGtqQOKNFSy7Jxb6TgoLG2AHTykQ0VTXh2m9qIv%2F28BTgVJbfgSahQRGHiviu1EiQtlch0nx316JBPY%2BWxSaB6Jb0DlSvmu4FEQIBtVeXdbWGwsoDiRasgO9%2ByRC4bTPjlGU6oR0yoj5WA6MtGDB11GPny69Crnm3k6ujI0gZn1GJbF748oJ9X6dm85T6xFDbGXHLbMalGDxaYOm%2BEgqYN1iguufxTBykM9RWKrVMSLTIFhaEF7eYvBckkYv%2B7z7QcKGlwK30UmruETMvK%2BSdk7QJSmPX5%2FOUYmwIiwg95LQ0TE3ohpwPkIxya1Jb%2BIwDHBZOkaaRk4PMqOhAwzOihygY6pgHhfvShcd6wOM3eH4GD1BdtZ%2Bh2jTIXBwSW1A4LZhc6sMVPp5F3%2FW8xPbNVeHiXYVghkJcJ54SC%2BGp0ZOrA45UdQfzL8iWrqRFMfJbUthvSmYUZkztVfAxmMDQcLyJrXqt6x4c2y%2FqFPJ05ZEoCuBIKl5Oxt85vbCaNGYcH8s3zI6zjtS7nD%2BhRovbgpqv%2FMzS6OPxypl7BnWTCoHqhbxUi3Q0CY0rs&X-Amz-Signature=95d85aa3209542b4d7b2eb8de43c5c153e3eb4bd6da1426238d6d1588fd3f23b&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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