Z axis lost its way while printing?
I just encountered a curious problem on a 16 hrs print.
After working normally for 15 hrs, the printer seemed suddenly decided that it should return to beginning and attempted to lower the hot end and print at lower layers, which of course caused the motor being stucked to the already printed part of the object, making a terrifying sound.
So I stopped printing and removed the object, and did the calibration. Y and Z axis worked just fine. The X axis refused to move across the mid point, probably because it was stuck before. This was fixed by a reboot, but my print was ruined.
I wonder is this a bug in my printer's firmware, or a bug in the slicer, or I have done something wrong?
RE: Z axis lost its way while printing?
Where did you get the gcode? Did you slice it yourself with Prusa Slicer? Or did you get the gcode from somewhere else? It sounds like a G28 got inserted somehow. Gcode is just ASCII text, you might try loading it into Notepad or Wordpad and searching for G28, there should be on near the beginning to start auto bed leveling but none after that.
-Bob
Prusa I3 Mk2 kit upgraded to Mk2.5s, Ender3 with many mods, Prusa Mini kit with Bondtech heat break, Prusa I3 Mk3s+ kit
RE: Z axis lost its way while printing?
@bob-2
Thank you for replying.
Yes, I sliced the code myself with prusa slicer. Can you tell me more about this G28 thing? I unfortunately had already deleted the gcode file so I don't know if G28 was inserted.
Also, before the failed print I mentioned previously, I also had a problem where my printer attempted to print all the *deleted* gcodes that I had once printed one-by-one, which of course created a terrible mess. This was solved by a restart of the machine and formatting my usb disk.
And after that failed print, I had another 2 failed prints where the printer stopped working with y axis parked at its farther end (180 side), with motor unpowered(I can easily push the hotend back and forth). This was solved, I believe, by reslicing the gcode.
Do you have any clue about this if you can share?
RE: Z axis lost its way while printing?
Are you using a USB thumb drive to hold the gcode? Or Octoprint?
It's unlikely that Prusa Slicer inserted a G28 anywhere other than the beginning. Prusa printers are based on RepRap, an open source standard created to give access to 3d printing to hobbyists. RepRap defined an instruction set for telling 3d printers how to operate. G28 is the code RepRap based printers use to home the print head which is a very bad thing to do if you have a print on the bed.
If you're using Prusa Slicer provided by Prusa3d then it's unlikely your code has an errant G28. I'm now wondering if somehow your printer somehow restarted the print, it's possible a bad USB drive might cause something like that, especially if you bought a fake USB card that has less space on it than advertised. Another possibility is the file allocation table on the card is poorly linked and cause the code to circle back. Maybe you should try another USB drive.
Regards
-Bob
Prusa I3 Mk2 kit upgraded to Mk2.5s, Ender3 with many mods, Prusa Mini kit with Bondtech heat break, Prusa I3 Mk3s+ kit