Cura 4.6.1 - Temperature drops by 10°C as soon as the print starts

[Ferocit 0]

Hello,

 

My print temperature drops by 10°C the second my print starts. If I set temperature to 230°C it drops to 220°C, if I set it to 235°C it drops to 225°C.

I did some testing*  and finally tried to slice the model (simple bed leveling test) with Prusa Slicer. This are the two temperature curves (left is Prusa, right is Cura):

 

 

Prusa works like it should, Cura doesn't. Not 100% sure, but I think it started as I installed Cura 4.6.0

I've used the default "Normal" profile, Generic PETG as material and the only thing I change were the temperatures: 230°C for the hotend, 75°C for the bed.

I've also tried different settings, like changing "Initial Printing Temperature" and "Final Printing Temperature" to 230° instead of the default values, but it didn't change anything.

 

Sometimes the temperature would go back to normal randomly. I couldn't really figure out when:

 

 

Printer: Anycubic i3 Mega (Marlin 2.0 Beta)

GCode: Attached

 

Any ideas? Really would prefer to stick with Cura.

 

 

* Things I've tested and checked before:

 

- Slicer settings: Printing Temperature Initial Layer is set to 0
- Slicer settings: Initial Printing Temperature is set to 230°C
- I've upgraded the hotend fan and replaced the original cover. So I thought maybe the fan is too good or the cover I printed changed the air flow or something like that. But manually setting the temperature and enabling the fan doesn't have that problem: https://i.imgur.com/8WcNUgX.png
- No manual offset in Octoprint
- PID tune
- Replaced hotend
- Changed offset in Octoprint to 10°C... nothing changed
- Checked gcode file for unwanted temperature change commands
- Updated to Marlin 2.0 beta

 

PETG_Bed_Levelling_Default_461.gcode

[Ferocit 0]

Looks like I am not able to edit my post:

 

I've tried it with an older version of Cura (4.4.1), but the problem stays the same.

[Ferocit 0]

Looks like I am not able to delete either:

 

So someone on Reddit gave me the solution: Cura default fan speed: 100%, PrusaSlicer default is some automatic setting. Reducing the fan speed in Cura gives me good results now.