Fix preheat regression bugs #631

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MrUnknownDE · 2026-04-05T16:24:32+02:00

MrUnknownDE commented

2026-04-05 16:24:32 +02:00

Originally created by @SoftFever on 2/23/2026

revert 769fc137c7

Description

Fixes several deal breaker regression bugs regards the preheat changes introduced in the PR #12266.
Fixes #12312 as well as below issues that will break machine print start action as it preheat nozzle before machine initialization where each machine usually has it's own logic to do a serial of check actions:

; HEADER_BLOCK_START
M104 S220 T0 ; preheat T0 time: 0s.  <=========
; generated by OrcaSlicer 2.3.2-dev on 2026-02-23 at 14:17:58
; total layer number: 135
; filament_density: 1.24,1.24,1.27,1.24
; filament_diameter: 1.75,1.75,1.75,1.75
; max_z_height: 27.05
; filament: 3,1
; HEADER_BLOCK_END

; THUMBNAIL_BLOCK_START

It also affects preheat efficiency, because it now won’t preheat T3 if T1 is currently printing and T2 comes before T3 while it’s still within the preheat time window.

Screenshots/Recordings/Graphs

Tests

*Originally created by @SoftFever on 2/23/2026* revert 769fc137c7 # Description Fixes several deal breaker regression bugs regards the preheat changes introduced in the PR #12266. Fixes #12312 as well as below issues that will break machine print start action as it preheat nozzle before machine initialization where each machine usually has it's own logic to do a serial of check actions: ``` ; HEADER_BLOCK_START M104 S220 T0 ; preheat T0 time: 0s. <========= ; generated by OrcaSlicer 2.3.2-dev on 2026-02-23 at 14:17:58 ; total layer number: 135 ; filament_density: 1.24,1.24,1.27,1.24 ; filament_diameter: 1.75,1.75,1.75,1.75 ; max_z_height: 27.05 ; filament: 3,1 ; HEADER_BLOCK_END ; THUMBNAIL_BLOCK_START ``` It also affects preheat efficiency, because it now won’t preheat T3 if T1 is currently printing and T2 comes before T3 while it’s still within the preheat time window. # Screenshots/Recordings/Graphs  ## Tests

MrUnknownDE closed this issue

2026-04-05 16:24:32 +02:00

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Reference: github/OrcaSlicer#631