Print head suddenly "drifting" during print

Good morning/afternoon/evening,

Just received a Snapmaker Original, and running a few test prints with the 3D print head before moving to laser and CNC. To note that I’m relatively experienced with 3D printing, since I already own two different FDM printers and one resin printer.

Now on Snapmaker Original, I have the following issues (besides bed adhesion which is probably due to a different calibration - my CR10S requires a much tighter calibration than Snapmaker it seems):

  • Sometimes when starting a print, the print head does not home to the correct Z height, so print starts literally mid air. Could not really figure out why, when this happens I stop the print, home manually, and restart

  • More problematic: after a few layers, all of sudden the print head X/Y origin position gets completely shifted by a few cm, so the layers above are of course printing mid air again. I could not find where to adjust the belt tension

  • The touchscreen UI is severely limited, so I’d like to connect Octoprint (and use Cura while I’m at it), however I could not find online the Cura settings (especially the print head gantry parameters).

Thanks for any help you can provide

Regards

To provide further insight, essentially when the drift happens the printer is moving quite rapidly the print head to the far right, for no apparent reason, and the print head remains at this location for subsequent print commands.

This is beyond frustrating. Three months wait for the shipment, only to get a non functional machine

I swapped the X and Z axis : the issue still persists on the X axis. I can’t finish a single print, after a few layers all of sudden the entire print head shifts by a few cm to the right, with the motor trying to push it beyond the limits.

So it looks like a control box issue to me.

The only time I’ve had an issue with the print head not homing correctly was after it skipped some threads because I tried to move it too fast. There are no belts in the Snapmaker, it’s all threaded rods.
I got it back by manually running it up against the limits of the rails, and ignoring the awful noises it made.

How fast are you printing? I had problems with skipping threads when we printed at 100 mm/s. Now that I’m only printing at 80 mm/s, I haven’t had any problems. When it happened, it shifted a bit less than a centimeter, about 8 mm? It made a pretty loud click when the shift happened.

I’m assuming you’re using Luban, since you haven’t gotten Cura working yet. I had some posts about getting Cura to work with the v1, but it seems those are all gone now. I configured everything manually by creating a Custom FDM printer. Here’s what I have:

The Printer settings:
Printer

The Extruder settings:
Extruder

The Start & Stop GCode:

Thanks for this info

For me the drift is sudden, it’s actually a sudden 5cm shift, so it’s not a matter of the stepper motor skipping a step

Oddly enough the issue is now gone, I managed two prints yesterday… Not sure why that happened

On the Cura settings, thanks for the info, I’ll test them. I especially miss tree supports in Cura, which are not available in Luban as far as I can tell.

Regards