MMU3 buffer retrofit for Prusa MK3/MMU2S LACK enclosure

Project file contains one complete set of segmenter mods (one for each side of the buffer). Only 4 plate holders are needed. The buffer leg and buffer holder will not be used with this mod; no need to print those. An additional (x4) 30mm M3 screws and (x4) M3nS square nuts are needed for assembly, along with (x2) wood screws to mount to the LACK enclosure (presumably, the ones that were holding the MMU2S buffer there can be reused).

Print using Prusa's recommended settings of 0.2mm QUALITY, 2 perimeters, 20% grid infill. The white, grey, and number inserts are optional, but if you're printing this, you probably have a MMU2S that is about to be upgraded. :-)

(The clip model is not included in the project file, but five will be needed for the spool holder adapter. The same printer settings apply.)

To assemble:

Assemble the buffer per the MMU3 Assembly Manual. Position the segmenter sidebar so that the screw tab points outward with the wide part of the countersink facing the buffer slots. The 30mm M3 screws will secure the sidebar to the rest of the segmenter. Check positioning before inserting the screws - the tabs should be on the same side of the buffer (and the symmetrical buffer makes it really, really easy to mess that up (guess how I found that out?)). The buffer will mount on top of the LACK enclosure using the same screw holes as the MMU2S buffer. Route the 650mm PTFE tubes from the MMU3 unit through the holes in the back panel of the enclosure and connect them to the appropriate segment.

The PTFE tubes from the buffer segments to the spools have been shortened to 450mm in my installation. You might want to lengthen the #3 tube a little and/or shorten the other tubes, but this length provides a decent balance. The slack in the tubes can be adjusted somewhat by moving the end of the tube between the spool and the clip. The spool-side tube can be routed either over or under the MMU-side tube; use whichever option makes the tubes behave.

This mod is meant to be used with the Prusa Enclosure V2 - MMU2S spool holder adapter mod, which is posted separately due to different licensing.