Resuming a print after failure
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So I have had a rather long print going and it just failed, was printing in air for some time.
I would like to resume this at the layer where it failed, and I know now if I use the pause and resume functions it will only resume where it is now, printing in air.
I've cancelled the print and moved the effector away (it's a Delta) and turned the heater off for now until I can get home.
What I'd like to do is move the nozzle down to the last completed layer and record it's height.
Then edit the gcode to pick up from the next layer, my problem is that the extruder uses relative movements. I've never dealt with that before.
How might I modify the gcode to pick up at that point?
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I've resumed a failed print similar to that before.
I basically measured the height of the printed model and used the gcode preview in the slicer to find the layer where it failed, then used a text editor to find that exact layer in the gcode, copied the rest of the gcode into a new file, and created a custom gcode script that allowed me to heat up the extruder and bed again, set the Z height manually with a G92, and start printing again.
Relative extruder movements are no issue at all. Absolute extruder moves would be an issue however.
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So if i've not powered it off, it still knows it's current position. I shouldn't need to do G92 should I? I should just be able to measure the height as you did. Download the gcode from DWC, and strip out everything up to the next layer to be printed. If I manually heat the nozzle and bed, then I should just be able to print that gcode correct?
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Yes, just make sure you don't have any homing commands at the start of your resume print. Just set the position manually and away you go.
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Yep, that seems to have done the trick. It's resumed, with no noticeable issues. Thanks.
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I posted about resuming in a different thread. i know this is an old thread but I have a question along the same topic. i have a delta and just recently, my 20 hour print failed 80% of the way. the magball arms basically fell off and the hotend was just squirking plastic everywhere. I paused the print, and after putting the arms back together. I cancelled the print but during that step, my end gcode script has a G28 at the end. IF I were to resume the print, how will I do that? I always do a delta calibration before each print to make sure the nozzle is flat across the bed but I lost that data when I homed it. I did a G92 Z0 on top of any random part of the print and then moved the nozzle up to 0.3mm and jogged it around to see if it was 0.3mm across the entire print but it was not. it had a upward curve to it the further it goes towards the edge. I modified a bed.g file to only probe 4 areas on top of the print to get a new delta calibration. then establish the top part of the print as the new G92 Zn where n is the layer at which it failed. I modified the Gcode script by removing everything before Zn. I started the print but it just crashed into the print. It dived hard enough that I think it moved my glass bed and I ended up having to trash that entire print.
i guess my concern is does it matter what M665 Hnn I use? I usually have the H a little taller than my printer max travel to make sure it hits the endstop but I don't know if it is preventing me from resuming correctly.
Thanks in advanced.
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@tekstyle said in Resuming a print after failure:
i guess my concern is does it matter what M665 Hnn I use? I usually have the H a little taller than my printer max travel to make sure it hits the endstop but I don't know if it is preventing me from resuming correctly.
If the homed height isn't exact and you need a calibration at the start to get accurate results then I think you might be out of luck on using this resume method. I don't have any experience with resuming a failed print on a delta though, so maybe there is some way I'm unaware of.
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@phaedrux ok thanks anyways. ive been trying to set an accurate zmax with M665 Hnnn in config but it keeps resetting to another Hnnn everytime i reboot.
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@tekstyle said in Resuming a print after failure:
it keeps resetting to another Hnnn everytime i reboot.
Do you have a config-override.g file and M501 at the end of your config.g? If so and you have already saved a calibration with M500 this would be over writing what you have set in config.g.
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I don't believe I do.