RichRap out of Gloucester, UK has been colouring his work with a new type of multicolour and multi-material extruder. 3 filaments enter – only one can leave. That sounds like an epic extruder in my book. RichRap’s extruder produce vibrant yet oversaturated coloured prints – not really the fidelity you need to make exact replicas – but damn, what a step forward. More after the jump.

All Glory to the Hypnotoad!

RichRap has been at for a while – only yesterday he announced the success of his 3-colour extruder.

It’s been over a year now since my first layer selective colour experiments and filament joining, not a month of RepRap has passed that I have not thought about multi-colour/material 3D printing. I started work on colour mixing earlier this year and had some promising results with a basic, manual setup. Things moved onto other 3D printing developments and I got sidetracked for a few months. Dual extrusion has been the focus for many machines, but this has some significant problems of alignment and oozing of the inactive hot-end and the fact you cant mix/blend materials with two separate hot-ends.

Based on what I’ve seen and read, he programs his extruders to push filament depending on direction or what layer the print is at. As RichRap calls it, A crude yet effective method. Depending on orientation, a print can be one color or another! He concludes,

I used up all my 1.75mm filament stock in these test prints, but I’m keen to build up a whole printer in glorious multi-colour blended wonderfulness! And Imagine using different materials, soft PLA for modifying hardness or doing a flexible ‘hinge’ in the part. or Glow in the Dark with a hint of whatever colour you like for daytime and night viewing. Mixing both ABS and PLA together would be an interesting experiment, maybe one to try at some point. For now more work getting the electronics a little more integrated and maybe a multi-fed Bowden version?

Go for it! – I think the biggest issue is purging one colour so that one could use another quickly. I’m surprised not a lot people are experimenting with injecting colour pigments into a white filament. (FYI all the parts are posted on Thingiverse)








This was created by extruding in a pattern, leaving a textured look. UNBELIEVABLE.




Source: RichRap