Master spool/Prusament adapter (minimal)

Updates:
- Dec 2024 The latest version of the FormFutura refill spool has a cardboard core: this will not fit this adapter anymore.

Description:
I looked at several adapters for refill spools that use the flanges from empty Prusament spools. Most had some big nuts sticking out: I wanted something more lightweight and I tried to use as little filament as possible. 
The adapterring is only 0.6mm thick; together with the ribs it's surprisingly strong. The spool is held together with two clips that snap into the hexagon holes on the flanges.

The width of the ring is in the filename: 
- 47mm (Formfutura old: was too narrow: use 49mm)
- 49mm for FormFutura (Will not fit the latest refill-spools with cardboard core).
- 51mm for Fiberlogy.
- 56mm by request from Mathysek.
I also added a slightly narrower version of the clips (for 47 and 49mm)
If you need another width, let me know. Or you can scale in the Z-direction in the slicer.

Printing
I printed in PETG with 0.4mm nozzle with 0.6mm extrusion width, no supports.
Infill at 100%; this only affects the clips and the pusher tool; the 3D model of the ring is hollow. 
The ring and clips use only 25g of filament, at 150% speed it takes about 1h30 to print.

Assembly
Should be self-explanatory, just make sure the middle of one of the clips lines up with the small notch on the Prusament flange. The other clip goes on the opposite site of the hub. Put the ring on the flange and push the second flange on the ring and the clips.

The clips can be undone by pushing with your fingertips; for convenience I included a little pusher tool.
If the spool lays on e.g. a table, there might be a small risc dislodging the clips if you push on the reel. To avoid this, just use a flush cutter to cut them even with the flange. Then the pusher tool definitely comes in handy when it's time to reload an empty spool.

Feedback and suggestions for improvement are always welcome, let me know how the model works for you.

Bart