Rotating Nozzle Platform

Allows to have up to 4 hot-ends for multicolor print.

Demo video: http://youtu.be/NfR9ofFEKFw

The rotation axis is tilted 10° (and hotends -10°) so that only the hotend in use is vertical and touching the bed (all other hotends are then a bit above).
I use it with E3Dv6 hotends, but I think it should work with any J-head hotend as long as the cooling part is not too large.