3 Extruder MMU, color mix/blend?
I've been flipping between Cura and PrusaSlicer for a few years and recently got the A10T. Setup of PrusaSlicer was easy and I had multi color prints done quickly. But I'm curious why there isn't any mixing/blending options or modes for the multi material printers. I've tried Geeetech's Color Mixer but it's a PITA trying to get it to work with my current configurations.
Is there anything in the plans for adding Start/Stop positions within other extruder sections for blending or adding a gradient/color blending option? (Like, Virtual Extruder 4 = 30% Extruder 1 and 70% Extruder 2)?
RE: 3 Extruder MMU, color mix/blend?
Why does PrusaSlicer not have mixing options? The obvious reason is that Prusa doesn't currently (and is seems pretty unlikely to) make any printers with mixing extruders, nor nobody has currently made any Pull Requests to add such so far. The later I might be doing some of at some point.
TL;DR: One option right now would be to setup a static mix vtools. For gradient and complex mixes, use a single extruder profile and use gcodemixmaster.com
Mixing hotends have quite a lot of issues, complications, and and pretty long learning curve compared to a standard one (PLA hydrolysis will ruin your day for example). It'll be cool when there is a reliable and decently supported mixing hotend. The only ones reliable ones I've read about so far have been custom hotends. The Diamond hotend (which I have) appears to be the most common for info, and I've not found anybody that has kept their printer build long term; "I disassembled it a few years ago" is a reoccurring theme. The A10T appears to be the next most common, but I have seen very little said about it. I'd like to experiment with that hotend, but its quite pricey.
I'm still in the process of building my printer to get repeatability better (its a delta, so even more complications, lol). My PrusaSlicer config has 16 tools and in start gcode I have several pages of M163/M164 to define the mix ratios on all 16 vtools. The UI gets pretty cluttered with so many tools, but it makes is pretty easy to pick a predefined mix. Planning to test, refine and cut down that list to mixes that are distinct, only did 16 as that was the default number of vtools in Marlin.
As for gradients, aka M166... If Slicer had gcode placeholder for last Z height, I could easily make predefined gradient vtools. If I get around to setting up a dev environment for PrusaSlicer, that will be the first thing I try to add. Though manually altering the M163 ratios and M166 z height is not the end of the world either.
Protip for PLA mixing, never set any extruder to 0, always extrude from all. This will help prevent the PLA from the unused extruder from hardening in the hotend and help prevent heat creep. I jammed the first nozzle so many times when trying 0:x:y or 0:0:x mixes. I've also defaulted T0 to 1:1:1.
And if you just want the crazy multi-color toothpaste effect mixing hotends tend to have (which is what I was atracted to) verses actual color mixing, check out filablend.com