Customizable 3030 (System30) T-Slot Cable Holder

This is a screw-less cable holder for the System30 T-Slot Aluminium Extrusions (e.g. Prusa MK3 frame). Disassembly of the aluminium extrusions is not required.

Customiser settings:
1. holder_ln
- length of the holder

2. holder_id
- internal diameter of the cable holder

3. holder_th
- minimum thickness of the cable holder

4. loosen
- how much to loosen the T-slot fit