MMU3 Extra Long Spool Holder Guide

Rationale

I wanted to put my MMU3 spool holders inside a dry box, but the included spool holder guides are too wide to fit 5 spools in the box I wanted to use. I could fit 5 standard 1 kg spools in the box without issue, so I made this spool holder guide to span the width of the box and allow free movement of the spool holders on the entire length of the guide.

Description

This is an extra long guide for the MMU3 injection molded spool holders. It holds all 5 spool holders and is designed to fit perfectly inside this Ezy Storage 52.8qt IP67 Waterproof Storage Box.

I modeled this as a single part in Onshape, then split into parts with dovetail connectors in PrusaSlicer. I’ve included files for the split version and the single part, and a link to the Onshape file for convenience.

The dovetail connections are very snug and I ended up just press fitting the parts together with no adhesive. I printed them with Prusament PETG Jet Black. Here are the settings I used to split the part with dovetail connectors:

With the spool holders in place on the guide, I drilled holes in the box just large enough for the 4mm PTFE tubes to fit through and secured them in place by attaching a cable tie VERY tightly on either side of the openings.

I also replaced 2 of the PTFE tubes between the box and the buffer with longer ones since they were just barely reaching in my setup. In case anyone needs to do the same, this 2.5mm ID × 4mm OD PTFE Tube is the same inner and outer diameter as the ones that come with the MMU3 (though different than the one between the MMU3 and extruder) and it is easily cut to size.