Problem resuming after pause

JKaechler

If I pause a print, make a change to filament or something, then hit resume. it resumes fine, except that the Z height is higher than it should be. It looks to be maybe a millimeter or maybe 0.5mm above the print.

Here is my pause macro:
; pause.g
; called when a print from SD card is paused
;
; generated by RepRapFirmware Configuration Tool v2 on Tue Feb 26 2019 22:23:49 GMT-0600 (Central Standard Time)
M83 ; relative extruder moves
G1 E-10 F3600 ; retract 10mm of filament
G91 ; relative positioning
G1 Z5 F360 ; lift Z by 5mm
G90 ; absolute positioning
G1 X0 Y0 F6000 ; go to X=0 Y=0

and here is my resume:
; resume.g
; called before a print from SD card is resumed
;
; generated by RepRapFirmware Configuration Tool v2 on Tue Feb 26 2019 22:23:49 GMT-0600 (Central Standard Time)
G1 E10 F3600 ; extrude 10mm of filament
G1 R1 X0 Y0 Z5 F6000 ; go to 5mm above position of the last print move
G1 R1 X0 Y0 ; go back to the last print move
M83 ; relative extruder moves

What might be going wrong.

Wyvern

(Pause)
M83 ; relative extruder moves
G1 E-10 F3600 ; retract 10mm of filament
G91 ; relative positioning
G1 Z5 F360 ; lift Z by 5mm
G90 ; absolute positioning
G1 X0 Y0 F6000 ; go to X=0 Y=0

(Resume)

G1 R1 X0 Y0 Z5 F6000 ; go to 5mm above position of the last print move
G1 R1 X0 Y0 ; go back to the last print move
M83 ; relative extruder moves
G1 E10 F3600 ; extrude 10mm of filament

That is mine, which should function close to what yours is doing, except I extrude after resume positioning , not before.

What type of printer do you have? is your Z axis binding?

Phaedrux

Firmware version?

JKaechler

Firmware Name: RepRapFirmware for Duet 2 WiFi/Ethernet
Firmware Electronics: Duet WiFi 1.02 or later
Firmware Version: 2.02(RTOS) (2018-12-24b1)
WiFi Server Version: 1.21
Web Interface Version: 1.22.6

This is a home built AM8 machine. 2 Z motors with lead screws, belt drive X and Y
I have a paneldue on it, and i use the pause and resume buttons on the control screen. I assume they trigger the pause and resume .g files respectively.

Phaedrux

@jkaechler said in Problem resuming after pause:

I assume they trigger the pause and resume .g files respectively.

That's correct.

Does it looks like it's skipping a layer? Is the nozzle fully primed before it starts printing, or is it oozing out while returning to the resume point?

Is the movement of your Z axis repeatable? If you move it up and down repeatedly does it still return to the same point? Backlash, skipped steps?

JKaechler

@phaedrux its not skipping steps. backlash could be an issue. i may simply put up with this issue while i work thru printing the parts to rebuild my x and z axis to ride on the openbuilds rails instead of the smooth rods.

I have had no end of trouble getting reliable motion on the stupid smooth rods.

Phaedrux

You could test it without raising and lowering the print head on pause. Technically everything already printed should be below the nozzle anyway, but you still might cause a drag line across the layer or catch on a lifted edge, but that's true of any travel moves on that layer anyway.

JKaechler

@phaedrux
thats a good idea. i will give that a whirl.
I am also troubleshooting my first endeavor into dual extrusion. Surprisingly the duet took to it like a duck to water. its the gcode and Cura that are giving me greif.

and the Y-splitter on the bowden tube. I think a Cyclops is in my future.

dc42

G1 R1 X0 Y0 Z5 F6000 ; go to 5mm above position of the last print move
G1 R1 X0 Y0 ; go back to the last print move

That second line won't do anything because the first line has already moved to the same XY coordinates. Did you mean the second line to be G1 R1 X0 Y0 Z0 ?

However, the firmware should restore the original nozzle position anyway when resume.g completes.

JKaechler

@dc42
well,
I copied those pause and resume files from another firmware load. So I didnt even catch that line should have stated Z0 instead of Z5.

I have edited the pause and resume files as Phaedrux suggested to remove the Z lift and just go to X0 and Y0 during a pause. I am also going to change the order so that the re-prime of the nozzle happens away from the print. i think that might reduce the chance of getting a blob.

dc42

I meant did you mean the second line to use Z0, not the first.