I wanted a filament spool holder that:
- fits every spool
- allows quick and easy spool changes without tools
- holds the spool tight while maintaining low friction
So I borrowed the design of the double countersunk spoolholder with ballbearings, added a large thumbwheel and - to make it even easier to use - I combined the wheel and the front spool insert into a single part.
To achieve this I designed the thumbwheel to hold a long ( 30mm ) M6 nut and made the two front bearings wider ( 13 mm inner diameter ) so they can run on the center cylinder of the thumb wheel instead of the threaded rod directly.
Now you can take off the combined front part with one hand only and also fastening or releasing the spool is a lot easier. Due to the momentum of the big wheel you can give it a good turn and it will keep turning all the way in or out. A locking nut or wrench is not required. Hand tightening the wheel is enough. Thanks to the low friction of the ball bearings the screw won't loosen itself.
- M6 threaded rod ( if your printer doesn't have one attached already )
- M6 long nut ( 30 mm, SW 10 )
- 2 x ball bearing 19-13-4 mm
- 2 x ball bearing 19-6-6 mm
- Printed parts 1-3
Take part 2 ( the thumbwheel ) and insert the M6 long nut.
Take one 13er bearing and push it onto the wheel's center cylinder.
You might have to use a file on the cylinder to make it fit because in order to slice and print without problems I made the cylinder slightly wider than 13mm. Then push part 1 onto the bearing. Finally push in the second bearing. You might have to use a small hammer because it is supposed to be a tight fit. If it won't fit with a gentle strike of the hammer then you can try to adjust the clearance variable in the OpenSCAD file. It is adjusted to my print settings which are: PLA, 0.5 nozzle, 0.25 layer height.