I was printing a pad, for a woodworking clamp, with TPU filament. I had to stop mid print to go to a visitation for a friend’s mother. The print had just reached the 7mm layer when I stopped it. I tried “pause” hoping the bed and hot end temps would go to 0, and I could just leave the machine on, reset temps on return, and then “unpause”. Nope. During “pause”, it does not give you access to control temps either. So, I stopped it and shut it down.
To restart, I went back into TinkerCad and erased the bottom 7mm of the clamp pad. I then uploaded it to AstroPrint and generated the new gcode. On the Ender 3, I changed the “Z offset” from 0.02 to 7.02. It restarted the print at the right place and completed the print correctly. It did have an issue with bonding the new print to the bottom print on one side of the pad. E0006 adhesive repaired it. If I do it again, I’ll take a heat gun to the bottom print and bring it up to 70° or 80°C before restarting the print on top of the bottom print.
Remember to reset your “Z offset” back to your original setting after the print is finished.
I have to ask how long were you gone? I’ve never stopped a print to go somewhere. In fact I’ve sat in my barbers chair and we watch a print I had going while out and about. Looked at prints in progress in the grocery store, my cousins house and have had prints go into the wee hours of the morning while I sleep.
It was a good 3 to 3.5 hours. I’ve got a Kasa camera on mine to watch it from my recliner. If I have to leave, I can watch it and text the wife to cut off the printer when it is complete. I don’t leave it running while asleep or gone.
This happened to me again yesterday due to a clogged nozzle. Once I found it, I stopped the small storage box print and measured the print at 5.8mm with the calipers depth gauge end. I pulled the hot end, replaced the nozzle, and reassembled.
On TinkerCad, I removed the bottom 5.8mm of the box bottom. Then in Cura, I generated a new .gcode file. Once that was on the MicroSD card, I inserted it in the machine. It took me a while to find the Z offset setting. On the V2, it is under the “Prepare” menu and then down a ways to “Home Offset Z”. I changed the Z offset to 6mm and started the new print. With the new nozzle, the Z position was a little lower than before and dragging a little on the old print. I figured that should help bond the new with the old and it did. The print came out good, but you can see a transition line at the 6mm height.
Don’t forget to reset the “Home Offset Z” back to your previous value and reset the bed level due to the nozzle change.