Manual two colour printing

There is a method, documented here that provides manual two colour printing. Part of the config is the use a pseudo extruders. I'm unclear what the number of extruders setting in Printer Profiles does, and should it be set to the number of psedo or real extruders? Any advice welcome, even RTFM if you point me to the appropriate section of the manual.

I would import his profile and then compare those settings :slight_smile:
He got a stock MK3 - so one extruder.
I guess one key element of his profile is the single_extruder_multi_material = 1 setting.

It looks to me, that this is a solid one colour base and a few colour swaps on the top layer.

I have no reason to believe the op is running Octoprint.

1 physical extruder but Prusaslicer allows (and requires for this method) permits psedo extruders. This method sets 2 extruders with different colour filaments declared.

Absolutly, single_extruder_multi_material is unchecked and extruders is set to 2

Yes, but it's not colour change by height. 2 STL, one being the "negative" of the other.

Looks to me like he replaced the toolchange gcode with a simple filament change gcode.
So my guess is that you don't have to change anything on the OctoPrint side.

toolchange_gcode = ; Change Temperature to the next required one \nM104 S[temperature[next_extruder]]\n;next  filament_colour= [filament_colour[next_extruder]] Extruder #[next_extruder]\n\nM117 change to [next_extruder] {(filament_colour[next_extruder]=="#FF0000"?"red"\n:(filament_colour[next_extruder]=="#00FF00"?"green"\n:(filament_colour[next_extruder]=="#0000FF"?"blue"\n:(filament_colour[next_extruder]=="#FFFF00"?"yellow"\n:(filament_colour[next_extruder]=="#000000"?"black"\n:(filament_colour[next_extruder]=="#FFFFFF"?"white"\n:(filament_colour[next_extruder]=="#00FFFF"?"cyan"\n:(filament_colour[next_extruder]=="#FF00FF"?"magenta"\n:(filament_colour[next_extruder]=="#C0C0C0"?"silver"\n:filament_colour[next_extruder]\n)))))))))}\nM600

If there are T1, T2, etc. commands in the gcode, then you may have to change the OctoPrint printer profile to reflect the Number of Extruders (and check Shared nozzle?).

Thanks for the input, soon as I get my printer fixed, I'll give it a go.