Large Spool Holder - desk mount, optional friction brake

This is the desk top version of the large spool holder - wall mount, 2 versions with or without friction brake. Due to ball bearings, there is virtually no resistance.

It's mainly useful for Elegoo 3kg or Sunlu/Jayo 5kg spools, or whatever other supplier makes these. These heavy spools cannot be mounted on regular spooI holders, and certainly not attached to the side of the printer due to vibration. I wouldn't bother just for 1kg spools, there are better solutions out there. 

The brake is only needed if there are jerking movements from the print head/extruder, as it mainly happens on direct overhead feed. However, new 5kg spools unwind easily even on minimal acceleration so the brake helps here. The brake friction can be adjusted with added M8 nuts or washers.

The brake version will need a large print volume, like 300mm cubed. The version without brake will print on 240mm cubed. 

Print with PLA or whatever has reasonable layer adhesion, minimum 4 walls with a 0.4 mm nozzle. The soft strips for the frame and the brake need TPU 85A or 95A. 

No support needed, but the slots for the TPU strips come out a bit cleaner with support on build plate only. The support for the roller pin is designed in, break the base off after printing. 

Push the ball bearings on the ends of the roller,  with a tiny drop of superglue if needed but careful so it does not get into the seal ring and messes up the ball bearing. 

Slide the TPU strips in with a drop of dish soap if too resistant. 

Bill of materials:

300g PLA

30g TPU 95A

2 ball bearings 6002 2RS or 6002 2ZZ