I recently received a broken robotic chess game from a friend to do with as I wished. It was very old, and when disassembled did yield a variety of interesting components. The most useful piece was the assembly that moves the electromagnet around. With very little modification, they appear to be able to be easily convertible to a CNC machine.

I removed the weak DC motors/rotary encoders that it used previously, and I am currently 3D printing adapters for some stepper motors I have. Luckily the rods that connect to the belts are the same diameter as my stepper motors (+/- .1 mm), so designing couplers could not be easier. The next step is to mount the new motors one the couplers are done printing