WorkInProgress: diy cnc router

Work in progress, continue with caution :)

I decided to build a desktop cnc router by reusing stuff I had laying around, sourcing free parts where possible, and only buying things were needed, preferrably second-hand. Therefore the files are tailored to my circumstances, and the printer (a1 mini) and filament (pla matt BL) I used. This is mostly relevant for the diameters of holes that need to hold rods in place, or work as bearings.

Uses these belt coupler both for the Y table belt, and for the 2 openings left and right in the X sled:
https://www.thingiverse.com/thing:40710

Other parts needed:
- 2x standard-sized nema17 stepper motors (including cog wheels)
- 1x nema17 stepper salvaged from an old scanner, including the cog wheel setup that came with it, and a piece of the belt as well (this is most likely going to change soon, as the belt seems to slip
- 2x 6mm steel rods (salvaged from old printers)
- 2x 5mm steel rods (salvaged from old printers)
- 2x 3mm steel rods (salvaged