Dual Extruder, 2 to 1 hot end, filaments hit each other?
I'm new to Prusa and I really wanted to try the multimaterial painting options.
I'm using PrusaSlicer 2.4.0
I setup the dual extruder, painted the material and sliced, but when I print it looks like the 2nd filament gets stuck in the hot end. I thought I had a clog, but the first filament printed fine. if I manually unload the first filament, then manually load the 2nd filament then it will print. So, is there a setting that I'm missing in prusa that when it's time to change color, it pull the 1st filament back enough so the 2nd filament can load? I assumed that they both joined in the hot end at the same time, but that doesn't seem to be the case. It acts like they divide just before the hot end, so only one or the other can enter the hot end at a time.
Thanks
RE: Dual Extruder, 2 to 1 hot end, filaments hit each other?
Which Printer do you have?
regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
RE: Dual Extruder, 2 to 1 hot end, filaments hit each other?
I have an Elegoo Neptune 2D, it's basically an ender 3 clone with 2 extruders and single 2 to 1 hot end.
I actually got it to work last night, but I had to manually modify the gcode. Basically "T0" wasn't unloading the filament before "T1" was trying to load and print.
I did a search for T1 in the gcode and added these lines below just before the T1 call to retract the T0 filament:
T0
G1 E-50.000 F1600
It worked, Extruder 1 would move the filament out of the way and extruder2 was able to load and print and I was able to switch colors on the fly. I think -50 may have been too much, because it was a little under extruded after the color change.
I think PrusaSlicer is supposed to do that for me, I found the options in the Printer settings tab, in the Extruder 1 & 2 pages.
There's an option "retraction when tool is disabled" that looks like it's there to pull the filament back during a tool change, and it seems to have worked for extruder2 (T1), but not for extruder1 (T0). so maybe a bug in the software, or maybe I didn't set something right, more likely 🙂
See attached image.
any insight would be appreciated. I'm new to the pursaslicer, but I'm excited to use it, there are some amazing features.
Thanks,
Jimmy Ray. 
RE: Dual Extruder, 2 to 1 hot end, filaments hit each other?
Have you looked at the Mk2 MMU1 setup,
this setup, uses individual extruder motors to load and retract individual filaments during colour/material chnges.
I am not sure how much of the service is slicer related, and how much is printer related.
the standard setup is four extruders, but you can edit prusa slicer to only use two extruders,
regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
RE: Dual Extruder, 2 to 1 hot end, filaments hit each other?
I tried that too, no luck. Maybe my firmware doesn't support what I'm trying to do. Thanks for replying. 🙂