Filament spool holder using 6mm Airsoft BB's

I needed an adjustable filament spool holder for my MK4 and MK2.5 BEAR Prusa printers that can stand next to the printer. 

I couldn't find one on Printables that would meet my needs, because I didn't have real bearings to use at the moment, and didn't have the patience to wait until the next day. As an Airsoft player however I have a lot of BB's laying around that are exactly 6mm in diameter and perfectly round. So I thought, why not try to design a filament spool holder that uses these BB's as so called bearings to keep the filament spool rolling. This is how the BBFSH was created (short for BB Filament Spool Holder 😉 ).

The design features to identical holders that hold the filament spool. You can easily adjust the width by moving the holders sideways on the sliders. 

All parts are printed (Except the BB's for obvious reasons). The screws have M4 Hex holes for installation.

The design is surely not perfect, but in my opinion it gets the job done perfectly. As a side effect the roller makes a nice clicking and rolling sound every time the filament spool moves.

This design works just as a normal filament spool holder would. If you need an adapter to make this work with the MK4 and the MK2.5 my PTFE tube holders can be found from my profile.

Parts to print:

• 2x Holder 1
• 2x Holder 2
• 4x Screw
• 2x Slider

If possible, please post your makes and give me feedback on how to optimise the design!

Troubleshooting:

The BB's are not moving 

• Make sure the holders are clean from the inside. It can be that you need to use a knife or a little sandpaper to make the seams smoother.
• Remove 1-2 BB's from the holders, so that they are not too crammed.

The sliders are far too tight

• Print the sliders scaled to 90 to 95 percent depending on your printers accuracy.
• Clean the seams from both the sliders and the holders with a knife or sandpaper.

The BBFSH assembly is moving on a slippery surface

• Add small rubber feet to the holders (Not the sliders if you want the holders to be adjustable).

Screws are not fitting

• Print the screws scaled to 90 to 95 percent.