Colour Mixing Hotend.
First prototype functioning better than expected.
Watch this space.
(A collaboration between @Joshua_Rowley and myself at E3D Research Labs)
Just a quick teaser about our in-development mixing extruder. Fast colour response with homogeneous output is the goal here.
It should be noted that the long periods of green extrusion are intentional to show the ability to mix colour, as opposed to simply extruding one colour or the other. Fast transitions can also be seen in the video.
Aside from colour, the ability to mix polymers can be used for engineering applications to create materials with programmable mechanical properties, on the fly.
Cool! Also the soundtrack 
Very interesting! And yes, definitely great choice on the soundtrack 
Almost forgot to tag in @Richard_Horne !
Hope you can get it to work reliable. Will in that case be very, very impressed 
First gear work, it appears you are getting nice mixing and very quick changes. Quick question is this technique limited to 2 colors? I know prototyping more then that is crazy, but.
@Camerin_hahn
Prototype is limited to two for simplicity. We fully intend on going full colour, and our design allows that without much fuss.
Amazing! I guess the cold ends need one stepper for each colour?
4 extruders; CMYK, full-color FFF printing.
@ThantiK Actually we’ll need CMYK+White+(Maybe Clear).
You don’t have the white paper upon which to put your CMYK mix onto, so you need white. While you’re at it you may as well add an alpha channel (Clear) and get full colour and transparency.
6 is a nicer number than 5 to deal with from a machining standpoint anyway. So we’ll just do 6.
CMYKW just like they do for (direct to garment) DTG printing.
Very impressive results, guys.
How are you planning to support colour changing in software? Are you going to do it with several extruders at the slicer level or implement new gcodes for more ‘black-box’ style colour changes on the printer controller?
@Evan_Gillespie I think the plan is like the kraken (chicken and egg problem). Make it and support will come. First step is to make a thing that works, then it is to find a driver that works, then it is to build software that supports it.
@Camerin_hahn Exactly so, build it and they will come.
There is going to be a multitude of strategies and philosophies on how to do this from a software standpoint. Particularly over what gets handled at the slicer and what is handled in firmware.
Our intention is to support the community development efforts in whatever way we can in order that we come to a solution that works. In the form of supplying free hardware to software developers, bounties, etc.
Just for reference what size is that nozzle?
wow this looks awesome!!! if my printer could run more than two extruders i’d offer to beta test one!
Awesome!
Firstly. Awesome.
Secondly, @Sanjay_Mortimer Given recent experience with Kraken and woefully inadequate software/firmware support can I suggest you get someone on board to get started on the non-meatspace stuff early?
Really intrigued by the material mixing applications btw
@Tim_Rastall Don’t worry - already on it!