*Why another Filament Buffering Solution?* I wanted a solution that met the following requirements: - Does a decent job of handling retracting filament (duh) - Fully 3d printable while ideally using a minimal amount of filament - Retains maximum visibility of filament in the system - Easy to change filament
The openscad source for this project is available under the MIT license at https://github.com/x0pherl/Filament-Bank
This is a filament buffering system designed for use with the Prusa MMU2s, but should be easily adaptable to suit similar requirements or MMU2S modifications adding additonal filaments.
The original inspiration for this comes from [David Shealey](https://www.thingiverse.com/TNDave/about)'s brilliant design for his [Prusa MMU2 Filament Retract Bank](https://www.thingiverse.com/thing:3373895). His concept of a simple wheel releasing filament into a channel was the first workable buffering system for the MMU2S, as far as I'm concerned. However, this design suffers from two flaws. First, the walls of the chambers were designed to be acrylic plastic -- which had the advantage of being clear, but required some knowlege of working with acrylic.
This led [Piotr Karkovski](https://www.thingiverse.com/Karkovski/about) to create a modified [Fully printable Prusa MMU2 Filament Retract Bank (Buffer)](https://www.thingiverse.com/thing:3670379). This solved the orignial issue, and Piotr's instructions suggested maintaining visibility by using hex infill with no top or bottom layers. This was a very nice innovation, but it didn't help to solve the other issue with Shealey's original design.
Shealy's design relies on a paddle that slides up and down that, as you feed filament in, is supposed to force the filament to return up the other side. While this occasionally worked for me, I found it to be frustating in practice. [Garth Gangaway](https://www.thingiverse.com/GVader/about) set out to solve this problem with a new design, but this again relied on acrylic panels, and I did not like the clipping solution used on this model.
I am super grateful to all of these designers and their innovation. While I haven't used their original designs in creating this project, it certainly wouldn't exist without their original work, especially David Shealey's original design.