I wanted a way to keep the PTFE tubes off the MMU2 to be organized and not kink as they passed through the acrylic in my Lack Enclosure. I designed this originally with .17" diameter, but it was way too tight, so I increased the diameter to .19" and it seems to be working quite well. I tried to design it such that it would still allow a full 8" clearance for a model being printed, and it seems to work. It's short enough that if the machine is all the way forward and just barely touching the doors of the enclosure that the y axis can go all the way back and not hit. I have yet to test it, but it came out well and is keeping the PTFE organized and cleanly routed. I've printed several prints with it in place and the MMU2 seems to have no trouble.
I used M3 screws and nuts and they worked quite well to hold it in place. The holes in the acrylic are ½".
The author hasn't provided the model origin yet.