# How to resume an unfinished project

I was printing a lid for a box in my Ender 3 pro printer. But I don't know why it stopped printing and moved aside when it does in finished printings. This happened at midnight and I didn't see it until I woke up. In the hope for a resume I didn't remove the finished part from the printer bed. So now how can I resume this printing from where it left. The total width of the lid was 3 mm and it printed 2.4 mm now only 0.6 mm part left to print.

• 2 questions: did you power down the printer since finding it and what does the screen on the printer show? – Trish May 19 '20 at 11:40
• First I didn't turn it off and tried to find the resume option in the menu but I couldn't find that and that may mean it showed as if completed but I don't remember the screen now. I was a little sleepy then after not finding the resume I turned it off – asduskun May 19 '20 at 11:42
• if there was a power out, you just need to press the wheel once to get resume... but shutting the machine off prevents any resume. – Trish May 19 '20 at 12:44

Provided that the print hasn't come loose from the bed and you know the layer height or layer number, you can edit the original G-code file. The following hints should be taken into account:

• Don't use G28 or G29 instead use G28 X Y (please )
• Manually position the printhead at the correct Z height and instruct the printer to use that height for reference: e.g. when the print stopped at layer 12 with a 0.2 mm layer height (2.4 mm height or use the measured height with a caliper) define G92 Z2.4
• Make sure the hotend is primed before resuming printing
• Cut all the G-code present in the file prior to the layer you want to start printing (e.g. search for G1 Z2.2), but do add bed and hotend heating, e.g. respectively M190 S60 and M109 S200

What you can also do is:

• Reprint the whole print
• Reslice the print where you have sunk the print 2.4 mm into the bed in the slicer just printing the top face which you glue on later.
• Thank you very much for all information. A last question, I use Cura for slicing. How can I only choose the top part in an object ( which is the part left after that 2.4 mm) and print only that? – asduskun May 19 '20 at 13:23
• @asduskun If you drop the STL through the build plate in Cura (you might need to disable snap to build plate option) until the 0.6 mm is left above the build plate. If you slice it, the part under the build plate is omitted upon slicing. – 0scar May 19 '20 at 13:50
• 👍🏻 thanks a lot – asduskun May 19 '20 at 14:20
• That's pretty much the only way, but acknowledge that the new print might have adhesion problems to the old. – Trish May 21 '20 at 9:15