Large spool holder - wall mount, friction brake

Problem: Large spools cannot be hung on the printer spool holder, due to fitment, stability and printer movement (at least on my Qidi Q1 pro).

I use 5kg PLA spools for large prints like loudspeaker enclosures, as available from some manufacturers like Elegoo, Sunlu and on eBay, in order not to change the 1kg spools mid print leaving ugly ring marks in the part. 

So after trying all sorts of stand mount solutions which never seemed to be fitting the different spool sizes, taking up too much space or not unspooling well, I came up with this universal design for 1-5kg spools. This works well for materials like PLA (and ABS), which do not need drying while printing.

Maximum spool size: 130mm wide, 300mm diameter. 

In the pictures: 1kg, 3kg and 5kg spool.

Due to ball bearings, virtually no resistance. However, once accelerated by the jerking extruder, a 3kg or 5kg spool will overshoot and unspool, causing filament tangle. 

This is prevented by the friction brake on top. The deceleration can be adjusted with added weight of M8 nuts. 

Spools can be fixed to the roller with the conical knobs, so they are centred and unwind evenly. 

Roller rests on the bearings in the frame, just lift out. 

Print and assembly:

I used ASA, frame with 4 walls and 15% gyroid infill, for other parts 2 walls 10% infill.  I guess any PLA will work too. TPU 95A for the strip.

Support base for the roller is designed in, and breakaway after printing - no support in slicer needed for any of the parts.

Ball bearing on each side of the roller, superglued onto the roller. 

The TPU strip goes into the slot of the brake.

Mount the brake to the frame with M6 bolts.

Metal hardware needed:

2x ball bearing 6002 RS

2x bolt M6x30mm with nuts

up to 10 x M8 nuts for the brake weights

3 screws or bolts max 5mm to mount it to the wall.