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Cura multiple [4!] extruders json works, GUI doesn't

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I want for an experiment slice something with 4 extruders. I managed to change the definitions json and added the necessary exruders json files and Cura starts OK. I can chenge the number of extruders in the machine settings, but I don't see the 3rd and 4th extruder in the GUI/menu on the right. I also don't see in in the right mouse button menu.

Is this a [known?] bug or am I missing something...

some snippets of the definitions json I changed:



"0": "ultimaker_original_dual_1st",

"1": "ultimaker_original_dual_2nd",

"2": "ultimaker_original_dual_3rd",

"3": "ultimaker_original_dual_4th"


cheers / joris

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If you want to use your json files, make sure that apart from changing "position" in "metadata" and "default_value" in "extruder_nr", don't forget to change "maximum_value" in "extruder_nr" to "3" for all 4 extruder json files.

Yes, there's quite a bit of redundancy in those files.

Edited by Guest

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Same here. Tried to add a 3rd extruder to the Mark2 profile. Double checked all the position, default_value, maximum_value settings in the 3 corresponding extruder json files. Even removed everything in the Mark printer definition json to make it look like the custom json.

No success.


Don't forget to increase the default value for "machine_extruder_count" in the definition file.

"machine_extruder_count": {

"default_value": 3


I made a quick test... works for me... :)



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Disregard what I said about cache, do what @foehnsturm says. The newly added printer will get the same profiles the old one has, including your custom profiles.

The problem you have encountered is that when a printer is "added" in Cura, a stack.cfg file is created for all possible extruders (in the "extruders" folder in your configuration folder). If you add new extruders to the definition, there will be missing stack.cfg files for the current printer, but these will be correctly created for any newly "added" printer.

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