Filament tube coupler using ring magnets and PC4-M10 connectors.

This one is based on SemaphoreSlims design but a completely fresh sketch made in FreeCAD for the magnets I had on hand.

Parts used:

(affiliate links!)

Neodymium Ring Magnets
10mmx5mm with 4mm hole
https://amzn.to/3pV4DBn

PC4-M10 Pneumatic Connectors
https://amzn.to/43k6u0t

PTFE tubes, 4mm OD, 2 or 2.5mm ID

Printed mine with the green PLA that came with the x1c but anything should work, 0.2 layers, no supports, infill as you like (I used 15% gyroid or grid) and pause the print at around 5.8 mm or layer 29 to insert the magnet (should be a nice, snug fit)

As i needed five to connect to one I did the first one with the magnet repelling the magnetic bed of the printer and all the other attracting it (hope I'm making sense here)

Threads are a snug fit as well, I use some PTFE-grease on the connectors when screwing them in. The PTFE tube should slide right down to the base layers and be visible through the 3mm hole.