Magnetic Coupling for filament guide to Orbiter extruder

I used this magnetic coupling on my old Prusa i3, and found it very convenient to use.

You got 2 ways to use it once mounted on the orbiter:

1. just as a plain funnel if your actual spool sits right above the extruder.
2. If you got a second spool somewhere else, you just place the magnetic reverse bowden on the coupler.

Print the parts in PETG with 5walls (0.4mm nozzle) as well as 0.2mm layer for best result. No supports needed.

You will need some parts:

.) ring magnet (OD=10mm, ID=4mm, height=5mm)

.) M6 brass screw, 2mm drill as well as a drillpress (you won't be able to do it with a hand drill)

The hardest part is to drill a 2mm hole dead center in the brass screw. (It took me 3 attemps, so take your time). Cut a 12 to 13mm piece of the screw. Use a hand drill and high rpm to smoothen the hole a bit. Afterwards saw a small slit so you can use a screwdriver.

Then screw it into the printed piece. since there is no thread in it, the screw will grip harder and you can easily mount it on the orbiter just by hand.

Screw it into the printed part, so that the outside lengt of the screw is just a bit unter 7mm (otherwise it wont fit into the orbiter). If you got some space to the magnet, its no problem.

Now again a tricky bit of work: placing the magnet in the correct way.

Best solution as I found is, that all mountings on the frame or on devices show the north pole (for example). So the reverse bowden has south poles on both sides.

That way you will never have a problem connecting your components.

The magnet should be a press fit. If it is too lose, you can use some super glue.

Last step is to cut a small piece of PTFE tube and press it into the magnet until you hit the screw. Than cut it flush with a knive.

Remove the old PTFE connector and screw on the new connector.

For the hand grips of the reverse bowden, just place a magnet on the mounted orbiter connector and press it in. Getting the PTFE tube inside is now the hardest part, because it is also a press fit. If you use a drill and the hole gets too wide, the PTFE tube migth slip out during heavy use.

Don't let the magnets smack together or they break!

Rev 1: 06.01.2022

Added an M7 version. Reason is, that many of you guys might have a spare E3D V6 Heatbreak lying around. That one has M6 on the hotend-side, and M7 on the coldend.

Just print the M7 version and use a handdrill to get the hotend inside and prepare a thread. Stay as straight as possible. 

After that measure between 12 and 13mm and use a hand saw to cut it off. Deburr the edge and also the center hole.

Place the cut off hotend into your extruder and screw on the printed part. Add the magnet in correct way as well as a short piece ot PTFE tube.

Ready.

other magnetic coulpers:

3030 extrusion: https://www.prusaprinters.org/prints/112089-magnetic-coupler-for-filament-guide-3030-extrusion

Mosaic Palette 2s: https://www.prusaprinters.org/prints/65505-mosaic-palette-2-spro-magnetic-coupler