Bed Levelling Issue (Nozzle offset)

Hi guys, i recently changed to 3d printing mode from cnc carving and then i tried to level the bed both auto and manually for 3d printing in a 3x3 calibration setting. To my surprise, when i try to do auto levelling, the nozzle moves in the front right corner as it is supposed to but the extruder tip is 5 to 6 cm off the printing bed corner (on the right side) and then while in motion it pushes down 1 to 2 mm slightly pressing the bed and then retracts a few mm again and comes towards the center of the bed and stops again (Video Attached). After this, I tried to do the manual levelling using the 3x3 calibration, and the nozzle tip was still offset by 5 to 6 cm on the right side while facing the bed and all the point of calibration in a 3x3 grid on the right hand side were literally 5 to 6 cm off the bed edge since the nozzle tip is 5 to 6 cm off the board. I need help with this guys. If any of u know whats going on, please let me know and i’d be super thankful. I only got my new print head delivered 2 days ago after a long month’s wait, so i wanna get it up and running as quickly as possible as i’ve missed the 3d printing function terribly, hehe. Thank you.

Your X axis is backwards? Cable on the other side.

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Looks like a cabling problem

Where does the head end up when homing?
The head should be starting on the left.


Or that.
I see now that everything is on the opposite side.



i love how folks think getting ‘creative’ and ignoring the build instructions is ‘harmless’ lol

Yes, because i had to make some minor changes in the setting of linear modules as i wanted to have the both door sides of the enclosure towards me and not towards the window as i can’t access the printer from the window side. Now, i understand why this is happening. Is there a way to get around it and not having to change my current setup. I was thinking to get a longer extension cable for the x module and then rotate it 180 degrees and since the extension cable would be longer, i would pass the cable through either from under the bed or around it and secure it from point to point so there no unnecessary free movement of the extended cable while the SM2 is 3D printing. What do u guys think???

the machine assumes that the X is the other way around, the linear axis is not a mirrored object, the amount of travel from the center point to each end is different. i suspect you will hit other issues eventually too (like your prints would be mirrored on the X too - i guess you can account for that in the slicer… ) and i dont want to tax my brain cells about what this does to the levelling mesh… i think it might be ok… brain hurts.

Could try flipping the sign on the values in M851 to reflect the mirrored probe offset, and you’ll have to check your home offset in M206.

Levelling should be fine. Everything will be mirrored vs what the slicer says.

I’m a little pessimistic because Snapmaker hardcodes some values or doesn’t stay true to what the Marlin documentation says. I don’t think this will work in a 100% predictable way the first try, but with enough tweaking I think it could work.

The best solution would also entail recompiling the firmware to reflect the inverted X axis, but I would need to pull that up in something with syntax coloring to see which flags are enabled.

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