Fabtotum 4th axis/feeder support

This is a support to attach the 4th axis of the FABtotum on top of the structure to make feeder tests. It provides:
- a shorter bowden tube from feeder to head.
- a slightly more stable structure than having it with adhesive tape (see fotos).
- full permanent access to the "feeder engage button".

It is based on the published STEP files imported in FreeCAD.
The source is available.