This is a small, inexpensive (<$10) CoreXY mechanism which illustrates how CoreXY works. When the user turns the two knobs in the same direction, the X axis moves. When in opposite directions, the Y axis moves. This is purely for illustration purposes, there is currently no attachment for a pen or pencil (nor laser nor extruder). However, the concepts learned from this can lead to scaling up and improvements and the addition of stepper motors. Required: 4 x 3mm by 100mm aluminum rods (or other material may work) 1m GT2 timing belt 6mm (this is overkill, a thinner belt should work) 6 x 3mm x 25mm (or longer) screws To print: 1 x Inner bearing 2 x Outer Bearing 1 x Frame 4 x Spacers 8 x Spindles 2 x Control knobs Optional: 2x Belt Connectors I used PETG but any material should work. I used 20% infill but use 65% to be sure, it doesn't take much longer to print. Here is a video of it working: https://youtu.be/tElMsCfxDCs