Prusa Multi-material Upgrade – Part 1

Over the weekend, I decided it was time to build my long-awaited multi-material upgrade for my Prusa 3d printer.  I had planned on ordering this way back in March, but the combination of my funds and other things I wanted to order at the same time being out of stock stayed my hand.  Still, after lots of different delays, I finally got around to ordering it and building it.

Overall, the build was fun, though there were a few frustrating parts.  The first thing that got me was disassembling the extruder and X-carriage.  I always get a bit nervous when it comes to doing this (I had to do it when I upgraded my bearings) because it’s way too easy to pinch a wire, overtighten the bearings, or mess up the extruder path.  All of these things affect the reliability of the printer, and since it was working reliably, I didn’t really want to mess it up.

Another thing that was assembling the idler barrel for the MMU itself.  Here, the issue was less about the fiddliness of the parts, and more about the amount of force required to do the assembly.  I found that inserting the smooth rods took a lot of force, and it was basically a one-way trip (I had one I wanted to get out, but ended up bending my Allen wrench instead).  This was disappointing, as it seemed to defeat the purpose of self-assembly, which was learning something about what I was putting together and be able to adjust/fix it later if needbe.

Lastly, I felt like the end of the assembly left a lot to be desired in terms of “what now”.  Specifically, there isn’t really much in the way of guidance on what to expect from the MMU or how to calibrate or tune it (or even what the buttons do!).  This left me scratching my head because without being able to see what it was supposed to do in isolation, I was left a bit at a loss when I had to troubleshoot it connected to my printer.  That being said, I want to give a huge shoutout to the maker of this video: MMU2S Theory of Operation which is awesome and helped my understanding a ton!

As of this morning, I’m still unable to print at all, and this is where the lack of documentation and information in general really left me hanging.  I hope to get to the bottom of it soon, because this is the next big thing in 3d printing for me, and I’ve been excited by what I could do with it!