MMU2S Single Mode Select Filament

I’ve got an i3 MK3S with MMU2S on it and I’m trying to start remote prints. These are all in single filament mode, though I am using some features like the spool join, so when I’m out of one filament it auto loads the next one.

When I load Goode into Octoprint and tell it to print, the menu appears on the printer display asking which filament I want to use. Can I make this selection in Octoprint? I’d like to start these prints without needing to be in the same room.

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Hi @ReturnZero!

Afaik, this only can be done at the printer.
Prusa introduced a new method since fw version 3.5.0 ( and it seems to be a bit difficult to manipulate them.
See also:

I finally figured this out yesterday. To specify the tool (which filament) to use you need to edit the gcode before you print. You can do this by installing the GcodeEditor plugin for Octoprint. When editing the gcode, look for the "Tx" near the beginning of the file (around line 25). If you change this to T and a specific number, it will select the filament for you instead of prompting you on the machine. The numbers range from 0 to 4 with 0 = filament 1 and 4 = filament 5 (i.e. "T0" for filament 1, "T1" for 2, etc.)

From what I can tell, the "Tx" replaced the "T?" that I see mentioned a lot on various forums.

Hope that helps!


You know, it would be pretty easy to write a plugin for this. It would simply need to watch the queuing phase for a Tc or T? or Tx command, put the print job on hold (job_on_hold(true)) while suppressing the T command, show a popup asking which filament to use (might need a setting to hold the number of filaments that can be used, as well as the min/max value), then send a T0, T1, T2... TN command depending on which filament was selected. Finally, the plugin would release the job-on-hold and you're off to the races!

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That would be pretty cool!

A plugin like that would be fantastic!

Fixed that for you.

Well, I already have one, but I'd be happy to take another one, lol!

I actually started this since I'm irritated to have to walk over to my printer for every friggin print.

That'll be fun. Check out foosel's thingiverse for a two-color game piece that she designed. I might print that up later.