incorrectly set temperatures for T0 and T1

[Rwide]

Application version
4.20.21

Platform
WIndows 11

Printer
Custom printer, Snapmaker J1

Reproduction steps

1. import 2 objects. select 1 extrudersfor each. Deactivate all skirts and brims
2. The temperature for extruder 1 is set to the temperature of extruder 2 during starting and possibly later when printing.
3. The problem seems to exist in cura 5.7 also. If I add 2 objects and assign 1 extruder for each and use a skirt, everything works fine but if i deactivate the skirt, the same problem appears. The extruders temps gets mixed up. Not sure if the problem is in Snapmakers interpretation of the gcode or if the problem is in Cura..

Screenshot(s)
(Image showing the problem, perhaps before/after images.)

Actual results
(What happens after the above steps have been followed.)

Expected results
(What should happen after the above steps have been followed.)

Project file
(For slicing bugs, provide a project which clearly shows the bug, by going to File->Save. For big files you may need to use WeTransfer or similar file sharing sites.)

Log file
(See https://github.com/Ultimaker/Cura#logging-issues to find the log file to upload, or copy a relevant snippet from it.)

Additional information
(Extra information relevant to the issue.)

[smartavionics]

I have no experience with multi-extruder printers but if you provide a simple project file that shows the problem, I will investigate.

[Rwide]

Hello. I made a mistake. I was trying to create a post proccessing script for conditional dual purge lines for my dual extruder printer yesterday and I must have accidently switched to another version of Cura while testing. The behaviour described is not present in your version. Sorry =).

It seems to me that in order to make such a post proccesing script work in your fork, one would need a few more data points in the generated gcode. Cura 5.7 presents those data points but unfortunately has the described behaviour above =D

I'm reffering to these:
Printing temperature for extruder T0
Printing temperature for extruder T1
Standby temperature for extruder T0
Standby temperature for extruder T1

Would it be possible to add that functionality?

[smartavionics]

Sounds easy enough. Can you provide me with an example of gcode that shows exactly what you are expecting to see. Just a few lines is sufficient. Thanks.

[Rwide]

Sure! Cura 5.7 does not present the standby temp unfortunately, but it does present the printing temperature and other data like this:

;Header Start
;Version:1
;Slicer:CuraEngine
;Printer:Snapmaker J1
;Estimated Print Time:11147
;Lines:85239
;Extruder Mode:Normal
;Extruder 0 Nozzle Size:0.4
;Extruder 0 Material:PLA
;Extruder 0 Print Temperature:220
;Extruder 0 Retraction Distance:1
;Extruder 0 Switch Retraction Distance:1
;Extruder 1 Nozzle Size:0.4
;Extruder 1 Material:PLA
;Extruder 1 Print Temperature:260
;Extruder 1 Retraction Distance:1
;Extruder 1 Switch Retraction Distance:1
;Bed Temperature:60
;Extruder(s) Used:2

In your fork, the temperatures are presented at the bottom, but there is nothing that specifies wich extruder is wich..

Best regards

[smartavionics]

I can't find where the above data is generated in the UM source. Could it be being generated by a plugin?

[smartavionics]

I found where that data is coming from, it's the snapmaker plugin.

[Rwide]

Ah I see, sorry about that =)

After deleting the plugin, there is less data in generated gcode. The remaining data looks like this:

;FLAVOR:Marlin
;TIME:5568
;Filament used: 22.0569m, 0m
;Layer height: 0.2
;MINX:87.205
;MINY:25.201
;MINZ:0.28
;MAXX:236.792
;MAXY:174.795
;MAXZ:10.08
;TARGET_MACHINE.NAME:Snapmaker J1
;Generated with Cura_SteamEngine 5.7.2

So at least there is one "normal setting" left (layer height). =)

[smartavionics]

I've started working on getting the temperatures output, here's an example (single extruder used)...

;FLAVOR:Marlin
;TIME:723
;Filament used: 0.157907m
;Layer height: 0.2
;MINX:113.313
;MINY:102.445
;MINZ:0.2
;MAXX:166.37
;MAXY:137.552
;MAXZ:10
;LINEARADVANCEPROCESSED
;Generated with Cura_SteamEngine master
M140 S45
M105
M190 S45
;Extruder 0 Print Temperature:200
;Extruder 0 Standby Temperature:180
M104 S200
M105
M109 S200
M82 ;absolute extrusion mode

Do you need the lines in a particular place or require any header or footer around them?

[Rwide]

It looks good as it is. I (chat gpt) can adapt to the situation. The only potential problem I can think of is that if the printer has 2 extruders but only 1 is used. What will be outputted?

Preferably in such scenario, only the used extruder setting should be outputted..
The post proccess script that i will make will start by looking at the gcode and determin what extruders are used and what are their printing and standby temps. If both extruders temps are always shown even if only 1 is used, it could be a problem..

I don't do much coding myself, but I have found that chat GPT, if given well explained descriptions of intended functionality, parameters, suggested logic and attempts can do wonders. =D

[Rwide]

A datapoint such as "extruders used: 1,2" would solve that problem if it arises..