Potential fix for other layers bed temperature not applied

[igiannakas]

Description

On occasion the second layer bed temperature was not set according to the filament preferences. This PR aims to introduce a fix for this. This issue seems to have been present since v1.6.4 or earlier.

This is a particularly difficult one to reproduce as it doesn't happen repeatably.

Requesting community testers to validate the fix.

Test needed:

1. Slice a model with a filament that needs a different temperature for the second layer
2. Change the brim setting to auto and slice - confirm that the second layer bed temperature is being emitted
3. Change the brim setting back to none and confirm that the second layer bed temperature is emitted

To see the Gcode window press key "C" on your keyboard. Navigate using the sliders to the second layer and at the start of it as shown in the screenshots below.

Asking for testers as its been particularly difficult to a) replicate that the issue is happening as its sporadic and b) validate that the fix is working.

When testing please confirm with your existing installation that the issue is happening first before trying the PR build. Please comment back below on whether a) it happened to you in the current build you're using alongside the version number you're running and b) if this PR fixed it or not.

When it works it should look like the below (line 774)

If it doesn't work it will look like this (line 773 only, no set bed temperature present)

Tests performed
As above.
I think that this PR also causes the bed temperature to always be set on the second layer but this also needs testing... Whether this is an issue or not remains open for discussion as its an extra Gcode command that is not needed but not harmful as the printer is already operating at that bed temperature so it will be just ignored.

Fixes #5485
Fixes #4676
Fixes #3015
Fixes #1853

[buzzhuzz]

Looking at the change I see why it is hard to reproduce: m_last_bed_temperature has random value unless explicitly initialized to the given value.

That is due to C++ standards https://en.cppreference.com/w/cpp/language/default_initialization

The effects of default-initialization are:

• if T is a (possibly cv-qualified) non-POD(until C++11) class type, the constructors are considered and subjected to overload resolution against the empty argument list. The constructor selected (which is one of the default constructors) is called to provide the initial value for the new object;
• if T is an array type, every element of the array is default-initialized;
• otherwise, no initialization is performed (see notes).

[igiannakas]

Exactly this. Which puzzles me as to why the constructor for this variable was commented out - this change was introduced in Bambu studio when porting prusa slicer since its first release and inherited over by orca. However I cannot understand why Bambu would remove the constructor initialisation for this 🤔

[SoftFever]

Thanks for taking care of this issue.
I merge it s omore people can test it.

[igiannakas]

Thanks for taking care of this issue. I merge it s omore people can test it.

thx! its a trivial change, shouldn't break anything :) :P (famous last words :P )

[fabio-s-franco]

This one have been driving me crazy. I am not sure where this is coming from, but for some reason it keeps bumping my bed temperature on second layer, causing the print to warp:

I tried already changing the filament's other layers temperature, but still, this stubborn gcode keeps showing up:

There is no filament gcode and the only override is retraction length.

My print start gcode is:

PRINT_START BED_TEMP={hot_plate_temp_initial_layer[0]} EXTRUDER_TEMP={nozzle_temperature_initial_layer[0]} RETRACT_LENGTH={(is_nil(filament_retraction_length[0]) ? retraction_length[0] : filament_retraction_length[0])} RETRACT_SPEED={(is_nil(filament_retraction_speed[0]) ? retraction_speed[0] : filament_retraction_speed[0])} UNRETRACT_EXTRA_LENGTH={(is_nil(filament_retract_restart_extra[0]) ? retract_restart_extra[0] 

I have just moved from PrusaSlicer and not off to a good start. So some of the parameters above may not be needed (like pressure advance I no longer put in filament gcode, which is a nice one).
There is nothing on layer change gcode that could cause this.

I don't have that temperature set anywhere.

If this is something else completely, I can create another issue. Or maybe I just don't know how to find whatever is setting that temperature.

[igiannakas]

Can you attach a project file so we can see/replicate the issue please?