In order to save space in my work area, I made myself frame for the spool that keeps the filament inside the spool during the retraction phase of the MMU2.

Once the plastic parts are printed, you will require a pair of bolts and nuts (Tip: Use the spare parts of the MK3 ). This will hold in place the PTFE tube.

Print instructions

I uploaded two files
The first STL is the whole assembly of the frame
The second STL have the parts nicely ordered in the bed so that it is ready to slice.

Supports: No
Layer height: 0.2mm

Once the plastic parts are printed, you will require a pair of bolts and nuts (Tip: Use the spare parts of the MK3 ). This is to hold in place the PTFE tube.