Modify Restart Location After Pause

NGP

Hello,
Is there a way to modify the resume location when pausing a print?
Here is the issue I am having.

We are running several Modix V3 printers with the Duet 3D controller.

The large format printer has regular trouble with the filament stripping out at the extruder when printing overnight, then when we come in in the morning, the nozzle is printing in mid air several inches above the model with no filament being extruded.

Ideally, pausing the printer, fixing the feed issue and hitting resume would be best since it doesn't have to be re-homed.
Restarting and saving the model has proven to be difficult.

How can I modify the resume location?
Thanks so much for your help!

Phaedrux

In such a case I would use a manual restart process.

Setup your cancel.g file to leave the motors active and cancel the print.

Measure the height of the model at the failure and then either edit the gcode file to remove any of the already printed section. Or reslice the file with the model cut at the right height and 0 bottom layers. Make sure the start gcode is blank, or at least remove any homing and heating commands.

Then you can jog the Z axis to have the nozzle just touch the surface of the print and manually reset the Z height using G92 Z0.

Manually preheat and prime the nozzle.

Now start your print again with the modified gcode and it should restart on top of the existing print. If you edit the gcode directly you can have it begin right where it stopped in XY space.

There may be other ways to do it using the built in pause and resume function, but the built in functionality doesn't know that it's been printing in mid air, so the resume point is saved at the time you press pause. You might be able to edit the resurrect.g file directly to point to the correct position to resume at, but I've not tested that.

https://duet3d.dozuki.com/Wiki/Setting_up_to_resume_a_print_after_a_power_failure

dc42

Here's another way:

in advance, set up your resurrect-prologue.g file.
pause the print. This will create a resurrect.g file.
rename the resurrect.g file to prevent it being deleted
cancel the print
measure the height at which the print failed
open the print file in Notepad++
find the line in the file that you want to restart at and place the cursor at the start of that line
Press control-G. This will display the byte offset of the cursor in the file. Make a note of this.
open the renamed resurrect.g file in DWC
locate the M26 command near the end and edit the file offset parameter to the value you noted
save the file
use M98 to run the file as a macro.