Thing files -> https://cubehero.com/physibles/cr3a7ure/Palette A selector for your extruders. It is best used with vertical X axis. I have not tested it yet cause i don't have any hotends. It mounts easily on your machine, in front of the big gear. You can mount up to 10 different hotends keeping palette's size reasonable. I designed it with the parametric&multiple extruder(link). I just printed one to see how it feels.i added alot of space so that the bowden tubes can move freely, but with 4mm tubes it could get smaller. More at http://nutbits.blogspot.gr/2013/07/multiple-cam-driven-bowden-extruder-and-the-palette.html