Making filament feeding smoother - MoFLuxband (by Andy AWD)


here’s an interesting post grabbed from the Chinese flux forum, using a ring and bb(s) for smoother filament feeding.


That’s an interesting looking item. I hope the bearings that are being used are airsoft pellets, as I have an entire bottle of them and I’m not an airsoft player. It gives me yet another use for the bottle of pellets. The previous use I’ve found was as a filler for silicon molding. The part could have been made via OpenSCAD and if the stl won’t fit my airsoft pellets, I’ll give a shot at building a similar design.
thanks for sharing it


It adds significant sound to operation… but I like the design!


I’m guessing a lot of the noise comes from the way the structure is shaped. It is a series of segments, not a smooth circle.


Since I’ve had a few filament spool drag issues too, I tried printing the MoFluxband. It has a few minor problems: mainly that it is made for metric (6mm) balls and that it isn’t a perfect circle. In the end I redesigned it specifically for cheap and easy to find 1/4 inch slingshot pellets (6.35mm) and made it much closer to a real circle. I’ll post the model and full instructions on thingiverse tomorrow.

Pro: MUCH reduced drag on the spool. I’ve not had a filament feed “click” since I started using it.

Cons: A little extra noise from the bearing (not much though) and the filament compartment needs to stay open (or at least ajar - not pressed down) or else the filament spool will simply start dragging on the roof instead.

It’s slightly tricky to print the ball bearing as it is very close to the size limit of the printer - you need to be very careful that the first layer goes down and sticks correctly. If you don’t monitor the first layer and make sure it is perfect, the whole structure will be compromised. I had to restart twice before I got it right.

Here’s the completed print with the pellets in place:


You know you can easily take the lid off the top of the flux. I’m thinking of combining this bearing design with a new lid design to house a bigger spool nicely.


Sounds interesting Gerhard. I’m also contemplating a better feed mechanism, using what I’ve learned with this bearing. If the TinkerCad file for my design would be useful for you, let me know and I’ll make it available.

Meanwhile the bearing is now available here:


I have finally solved this conclusively. The problem with the original design is that the lubricating stickers attached to the well of the filament holder interferes with the ball bearing. That is the root cause of the noise and also somewhat detracted from the best possible result. So I’ve created a different bearing that sits inside the flux well, but with the balls facing up. I can now insert a flux spool and give it a “spin” with my fingers and it will run 2-3 full turns before stopping. This design has no noise and immense improvement in friction. The link is here:


Along this same line I decided to go a different way with my solution. I purchased a full sheet of Teflon and just cut it down on the corners to be able to fit in the top without moving and allow the spool to spin freely on top of it. Seems to be working well so I thought I’d share.