I've watched a couple of wire holders / groove clamps show up on thingiverse, but they all only handle certain sizes of wire. This can accommodate anything from 1mm to 20mm in diameter.
This is designed for M3 bolts & nuts:
- x2 10mm
- x1 50mm
- x6 non-locking nut
- x3 matching washers
Make sure to print the Baseplate with the chamfered edges DOWN!
Use light glue where the Baseplate meets the Frames. These joints separate too easily otherwise.