Bought another Arduino to load Grbl on, since mine keep disappearing for use in other projects. Should arrive Thursday.

Printed the adapter for the Lego wheel to the Stepper motor. Had to adjust the model slightly with a less "flat" chamfer to prevent sags, and increased spacing around motor axle by 0.2mm in order for it to fit. Hopefully the Lego wheel fits, haven't received that part yet.