Cura sets wrong temperatures in dual print

[BenderBendingRodriguez 0]

Hey guys,

 

I am seeing some extremely strange behavior in Cura 5.1 when slicing parts for dual printing (IDEX) and I really hope someone can explain and/or solve this. In effect, the software is setting printing temperatures after an extruder switch, that are 10 °C below configured temperature with a very strange routine.

Below you see a commented snipped from a G-code covering the entire extruder switching routine. The red part is what confuses me.


G1 X112.592 Y157.239 E121.06755
G1 X113.158 Y157.239 E121.07666
G1 X113.585 Y156.812 E121.08638    --->>> Last bit of regular layer printing
G0 F2160 X113.739 Y156.658
G0 X113.739 Y157.239
M204 S5000
M205 X30 Y30
G1 F1500 E117.58638
;MESH:NONMESH
G0 F1800 X113.739 Y157.239 Z1.1
G0 F12000 X96.53 Y140.03
;TIME_ELAPSED:332.389368
;LAYER:8
G1 F1500 E113.08638   --->>> Filament retracts for extruder switch
G1 F1800 Z1.4
G92 E0
;Extruder2 End G-code
;Extruder2 End G-code END   --->>> placeholder
T0
G92 E0
;Extruder1 Start G-code
;Extruder1 Start G-code END   --->>> placeholder
M104 T1 S150   --->>> temperature of inactive extruder is set to stand-by
M105
M109 S185   --->>> temperature of now active extruder is set to 10C below printing temperature
M104 S195   --->>> temperature of now active extruder is set to actual printing temperature
M104 S185   --->>> temperature of now active extruder is again set to 10C below printing temperature!!! o0

;MESH:DualTest_B.stl
G0 F12000 X96.53 Y140.03 Z1.4
M204 S1000
M205 X12 Y12
;TYPE:WALL-INNER   --->>> regular layer printing commences again

 

 

Any ideas what is happing here and how to prevent this?

Edited September 10, 2022 by BenderBendingRodriguez

[GregValiant 1,489]

With the model loaded and Cura ready to slice use the "File | Save Project" command.  That will create a project file with the model, your settings, and your printer.  Post the 3mf file here.

Since it's an IDEX you have two separate print heads and extruders?

[BenderBendingRodriguez 0]

Hey Greg,

 

that would really be a great help, thank you so much. About the printer, it is a BCN3D Sigma R19.

 

Attached you will find the .3mf and the G-code it creates on my machine.

 

You can find the faulty line quite easily by searching for "M109 S215".

2020CityGenericV1_RR_L0.6-Wood_R0.4-Carbon_UHQ.3mf 2020CityGenericV1_RR_L0.6-Wood_R0.4-Carbon_UHQ.gcode

[GregValiant 1,489]

I just read your screen name.  This was last years Halloween costume.  I went for "Bender meets James Bond".  Got the first place trophy with it!!!

 

Here is the Tricky Dick "Double Cross" medallion.  It's all about the little details.

 

 

[GregValiant 1,489]

Back to the present.

Extruder 0 uses 2.85 filament and Extruder 1 uses 1.75 filament.  Is that correct?

 

At the beginning of Layer 43 the code switches to T1 and T0 is done for the duration of the print.

T1
M109 S225    ;Heat extruder 1 and wait
G90
G92 E-8
G1 E0 F200 ;Restore E position
G1 E8 F200;defaultpurge
G92 E0
G4 S1
G1 E-8 F1000
G92 E0

;Extruder1 Start G-code END
M104 T0 S0 >T0 is finished
M105
M109 S215 >Initial Print Temperature
M104 S225 >Print Temperature
M104 S215 >Initial Print Temperature

 

So what I am seeing is:

• Extruder0:
  • "Print Temperature" = 200°
  • "Initial Print Temperature" = 190°
  • "Final Print Temperature" = 185°
  • "Standby Temperature" = 100°
  • "Build Plate Temperature" = 0°
• Extruder1:
  • "Print Temperature" = 225°
  • "Initial Print Temperature" = 215°
  • "Final Print Temperature" = 210°
  • "Standby Temperature" = 150°
  • "Build Plate Temperature" = 0°

So it seems Cura is using the numbers you input.  When T1 starts the last run it starts at "Initial Print Temperature".

If you make all the temperatures equal to "Print Temperature" then this is the result:

T1
M109 S225    ;Heat extruder 1 and wait
G90
G92 E-8
G1 E0 F200 ;Restore E position
G1 E8 F200;defaultpurge
G92 E0
G4 S1
G1 E-8 F1000
G92 E0

;Extruder1 Start G-code END
M104 T0 S0
M105
M109 S225

 

You can see that those last M104 lines are missing and Cura sets the temp at "Print Temp".

 

I notice that you are a fan of different speeds for different line types.  I would respectfully suggest that you make all the speeds the same (other than maybe Outer Wall Speed as it affects the finish look).  When you bounce the speeds up and down you are bouncing the Flow Rate of filament through the Hot End up and down.

Edited September 11, 2022 by GregValiant