Dual Print Y for SmartrapCore V.2

After having spent a huge amount of time and many prototypes on a Twin Head support for the SmartrapCore (http://www.thingiverse.com/thing:995640), which is one of the most complex and difficult designs I've ever made, I realized that some people were successfully experimenting with a much simpler design : a Y-shaped piece that would lead the filament from two sources to a unique hot end, with a filament switching process that would only need a longer retract.

Here are the already functionnal