resume misses first Z move

[jltx]

Is this a known bug? I'm on 3.6.0-rc2

I am doing a sequential object print. I wanted to make sure the clearance was correct so I inserted an M226 between objects. It paused, moving the toolhead into the corner. I hit resume so I could watch the clearance. The toolhead moved to the next object position, but did not drop to the bed. It hovered in air printing, then dropped to the bed and printed the rest correctly.

Here is the relevant snippet of gcode. You can see the first object finishes at Z42.32. The first G1 command after the M226 correctly includes the Z axis but this is the only mention of Z until the bottom surface starts later due to a Z hop. What I observed exactly matches the idea that the first Z was missed, printing the perimeter in air at Z42 before correctly printing the bottom surface on the bed. This print had three objects and this happened exactly the same each time.

Since I was able to confirm that the toolhead clearance is good I have done subsequent sequential object prints without the M226 and they all complete correctly.

;WIDTH:0.506548
G1 F5759.607
G1 X115.245 Y285.308 E.02122
;WIDTH:0.505875
G1 F5768.303
G1 X114.853 Y285.167 E.02118
;WIDTH:0.50834
G1 F5736.57
G1 X114.221 Y284.79 E.03761
G1 X113.82 Y284.418 E.028
;WIDTH:0.509651
G1 F5719.841
G1 X113.435 Y283.884 E.03373
;WIDTH:0.510099
G1 F5714.159
G1 X113.144 Y283.165 E.03985
; stop printing object eab30995c923a37a9c8d92ac0c00f5ed166a4fb3.stl id:0 copy 0
G1 E-.8 F1800
M205 X5 Y5
M486 S-1
G1 Z42.32 F30000
G1 X221.89 Y62.896 Z42.32 F30000
G10 S220 ; set nozzle temperature
M226
M106 S0
;LAYER_CHANGE
;Z:0.2
;HEIGHT:0.2
;BEFORE_LAYER_CHANGE
;0.2
G92 E0

;AFTER_LAYER_CHANGE
;0.2

;M3291 B"DuetLapse3.snapshot"

;_SET_FAN_SPEED_CHANGING_LAYER
M204 P500
M205 X5 Y5
; printing object e966342e2d4ec02d8d7194e4724d29f4f5f432f7.stl id:1 copy 0
M204 T500
M486 S1
G1 X197.017 Y59.023 Z.2 F30000
G1 E.8 F1800
;TYPE:Inner wall
;WIDTH:0.499999
G1 F3000
G1 X196.822 Y59.089 E.00768
G1 X162.988 Y59.089 E1.2602
G1 X162.764 Y59.023 E.00869
G1 X162.698 Y58.828 E.00768
G1 X162.698 Y24.993 E1.26021
G1 X162.763 Y24.769 E.00869
G1 X162.959 Y24.703 E.00768
G1 X196.794 Y24.704 E1.26021
G1 X197.017 Y24.769 E.00868
G1 X197.083 Y24.993 E.0087
G1 X197.083 Y58.799 E1.25913
G1 X197.029 Y58.985 E.00721
G1 X197.333 Y59.362 F30000
;TYPE:Outer wall
G1 F3000
G1 X197.138 Y59.492 E.00874
G1 X196.867 Y59.546 E.01029
G1 X162.988 Y59.546 E1.26188
G1 X162.644 Y59.493 E.01295
G1 X162.434 Y59.353 E.00939
G1 X162.294 Y59.143 E.00937
G1 X162.24 Y58.873 E.01028
G1 X162.24 Y24.993 E1.26188
G1 X162.294 Y24.65 E.01295
G1 X162.434 Y24.44 E.00938
G1 X162.643 Y24.3 E.00939
G1 X162.914 Y24.246 E.01028
G1 X196.794 Y24.246 E1.26189
G1 X197.137 Y24.3 E.01294
G1 X197.347 Y24.44 E.00939
G1 X197.487 Y24.649 E.00939
G1 X197.54 Y24.993 E.01297
G1 X197.54 Y58.799 E1.25913
G1 X197.487 Y59.143 E.01298
G1 X197.36 Y59.333 E.0085
G1 E-.8 F1800
G1 X197.061 Y51.706 Z.6 F30000
G1 X196.007 Y24.849 Z.6
G1 Z.2
G1 E.8 F1800
;TYPE:Bottom surface
;WIDTH:0.502729
G1 F6300
G1 X196.731 Y25.573 E.03839
G1 X196.731 Y26.224 E.02436
G1 X195.562 Y25.054 E.06196
G1 X194.911 Y25.054 E.02438
G1 X196.731 Y26.874 E.09644
G1 X196.731 Y27.524 E.02436
G1 X194.261 Y25.054 E.13091
G1 X193.61 Y25.053 E.02438
G1 X196.731 Y28.174 E.16539
G1 X196.731 Y28.825 E.02436
G1 X192.96 Y25.053 E.19986
G1 X192.309 Y25.053 E.02438
G1 X196.731 Y29.475 E.23434
G1 X196.731 Y30.125 E.02436
G1 X191.658 Y25.052 E.26881

[Phaedrux]

@jltx said in resume misses first Z move:

3.6.0-rc2

Can you test with 3.6.0-rc3 that was just released?