A Multiple Extruder on a rotating turret idea for FFF / FDM 3D printers *Updated*

I’ve been puzzled for quite a while over the issue of the design of multiple extruders on FDM 3D printers. Most of the current design dictates an XY offset, which I feel cannibalizes on the XY build space of the printer. Not only that, it requires multiple feed motors, one for each nozzle, and that does add significant inertia to the moving head, generating much unwanted vibrations. Another common solution was to use bowden extruders, which suffers from poor retraction performance.
So I started to think of a solution that tackles all my peeves at one go.

I ended up with a design that can comfortably take up to 5 nozzles in a relatively small area, and only requires 2 motors – one to drive the feed gears, and another to switch the nozzles around a rotating turret. Each nozzle/hotend will have its own feed gears which will mesh with feed motor when it’s in the printing state.

concept for multiple extruder design
concept for multiple extruder design

So far it’s still a concept and a drawing. Altho I’m a mechanical engineer, I’m not in a good position to actually implement it due to my work commitments and lack of firmware programming skills. So I will leave this idea with the wonderful and innovative folks of the 3D printing world to try it for yourselves if you decide it’s worth a go.



From the (lack of) response in the reprap forum, I’d guess that my drawing sucked. lol

So I tried a sketchup model to see if I can get the idea across more easily.






7 responses to “A Multiple Extruder on a rotating turret idea for FFF / FDM 3D printers *Updated*”

  1. fkjjkl

    Nice, very good concept. Now some one just has to implement it 🙂 Thanks!

  2. ErwinPeters


    Interesting idea. Soon i’ll be receiving my printerparts. I’m look forward to experimenting with this interesting idea. Will you be available for feedback? Did your idea ever produce any prints?

    1. James

      Hey Erwin, sure I’ll be happy to discuss your findings with you! Unfortunately for me, I will not have time for the rest of this year to pursue this idea due to work commitments. :-/

  3. Albert

    I will develop this idea for my degree thesis. Let’s see what happens 🙂

    1. James

      Awesome! lemme know how it goes. 😀

  4. Mike Simpson

    Have you had any further progress with this idea?
    I am on about the forth iteration of a very similar project. There is a bit of detail in this forum post:- http://forums.reprap.org/read.php?4,400691,401921#msg-401921

  5. raghav

    Hey James,
    Love the idea, we were working on something similar.
    We’d like to collaborate. This could be a great asset for the open source community.

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