Jerk & acceleration value change after Resume APF

R006

Hey,

I am using Duet 2 wifi with RRF 3.5.0 rc3.

sudden change in jerk and acceleration after resume APF, it's set random value which is not in config and not in gcode.

gcode in which jerk is 300 mm/sec & acceleration 500 mm/s2, when i run the power failure sequence and after resume the print there is sudden vibration in X Y axis, so i am rum M204 to check it's acceleration and the result of it is 50000 mm/s2 and jerk is 600mm/s but gcode generated on jerk 300mm/s and acceleration 500 mm/s2.

so give me solution what should i do?
@dc42 @Phaedrux

Phaedrux

Can you verify if the behaviour is the same in 3.4.6?

R006

@Phaedrux We have already verified with 3.4.6 and 3.4beta3, and same thing is happening.

dc42

@R006 the generated resurrect.g file does not currently restore the M204 acceleration settings or the jerk settings. Feel free to create an issue at https://github.com/Duet3D/RepRapFirmware/issues.

T3P3Tony

@R006 to be clear, the reported values after a restore after power failure are the ones you have set in config.g?

R006

@T3P3Tony
no in config Acceleration is 3000mm/s2 and jerk is 300mm/s.

T3P3Tony

@R006 ok so are the values that are restored related to anything in your settings or gcode file?

JayT

@T3P3Tony :

I use this version too and have observed same problems. The value of acceleration on resume is not something I am able to trace from gcode file or config. Its some random very high value like 20000 or 50000. even jerk changes.

I have also observed, that despite setting max acceleration & speeds in config, its not limited on resume after power failure. Can you check this?

dc42

@JayT @R006 in the forthcoming 3.5.0-rc.4 the M204 acceleration settings are restored when resuming after power fail.

JayT

@dc42 :

Noted.
However, there are 2 more errors that appear on resume:
a) tool0 was not driven because its heater temperature were not high enough. heater fault. Yet it resumes, but why this error?

b) Loading the heightmap before setting duetZ0 - warning,

dc42

@JayT regarding (a) it's your responsibility to use M116 or a similar command in your resurrect-prologue.g file to wait for temperatures to be reached. Are you doing that?

JayT

@dc42 :

My resurrect-prologue.g file is as below, it has M116 to wait.
;rel
G91
G1 Z2
G28 X Y
;wait
M116
;rel
M83
M21 P1
G1 E5 F500
;mesh
G29 S1
;Buzz
M300 S600 P100
;Buzz
M300 S700 P1200
;Buzz
M300 S500 P300
;Abs
G90

R006

@dc42 hey,

After upgrading to the latest firmware version 3.5.0rc4, we observed improvement in print acceleration settings. However, the travel acceleration is taking random value: while print acceleration seems to be functioning correctly, travel acceleration values are fluctuating unexpectedly.

dc42

@R006 please check whether the M204 command in resurrect.g is setting the correct travel acceleration for resuming the print.

JayT

@dc42 :

with RC4, sometimes it resumes fine with minimal offset. Whereas sometimes it shift by 5-8mm in Y direction for me on resume after power failure. Mostly it shifting by >5mm happens when print height is <5mm. So i disabled meshbed compensation & tried. It still has the same problem.

There are instances when even at height 3mm, it resumes fine.
skew in YZ is included. Does that have any effect?

What should I check for ?
Shift is always in Y axis & amount of shift is more w.r.t X axis.