Hey all, so here's my design so far. Sorry I haven't been around for a while. Looks like you and I had very similar ideas for direct/bowden. I've got the one side risen to compensate for v5 height. Hotends get inserted and fixed to the mounting block. Then those get put through the x carriage with the extruder placed ontop, which is then secured in place from underneath. I still need to design the carriage, but as long as the extruders are true to their CAD files, then the snug fit should level them perfectly, and they fit between the bearings with enough clearance for fan ducts. If not, I'll have to implement some kind of spring mechanism for level similar to yours. I'm going to try to implement fan mounts similar to this: http://www.thingiverse.com/thing:364650 But I'm worried by doing so, I'll be forced to remove the cover. I'd love your files to try em out, I'll shoot ya a PM in a bit.