Simple easy-to-use space-saving MMU2 hanging spool system

Update 9/7/19: I fixed the M6 version of ACB. I had wrong thread pitch.

I don't have much room on my small desk for MMU2 set up. And while I found the filament wallet reliable, it's painful to manually change filaments. I looked at other systems and they are often complex and can fail / wear out. The printed hangers can break, as I learned, or add too much friction for my liking. There are some very nice, very clever systems out there, to be sure. But I like simple and easy to use. I k