Solved Using Duet 3 to control multiple extruders on a single carriage?

[annikamars]

Hello! I'm working on modifying a Prusa 3D printer to print with both thermoplastics and hydrogels, and I need to control 2 separate extruders on a single X-carriage. From what I've read, it seems like this should be possible with the Duet 3, but I'm quite new to this aspect of 3D printer design, and I was hoping some of the many more experienced people on this forum could offer some impressions as to whether this is a plausible task for the Duet 3. Thank you in advance for any insights! - Annika

[deckingman]

@annikamars It sounds like you just need more than one tool, which is plausible and easy enough to do, not just with Duet3 but also with the older generation Duet2.

[o_lampe]

@annikamars As been said before, you can define two tools on the same axis, but then your gcode must contain toolchange commands.
The other option is to define one mixing extruder and change the mix-ratio from 1:0 (only filament) to 0:1 (only hydrogel)
Changing the mixing ratio would also need to be in the gcode. It is less complex, but doesn't allow filament-retraction or purging a.s.o.
*) only works if both extruders use the same nozzle, which is unlikely here

By defining two tools you can write your own tool change macros, which could do all the prep-work you'd need.

[annikamars]

@o_lampe @deckingman Thank you both!