SM2 Bed Leveling

Does the SM2 use the UBL style of bed leveling in the Marlin code?
I presume it does since “G29” is used.
That’s “Unified Bed Leveling” for those who loath acronyms!
For more info see:

A question related to this, is anything saved when you do a Z-offset or is it only used for the current print?

No, not a G-code command. SM2 uses a customized bed leveling, it has interactions with TS.

Not using any bed leveling in the Marlin system?
How about my second question?

If you mean adjust the Z offset when printing, It’s only used for current print.

The custom bed leveling is a modification of Marlin bed leveling, we use the same way as Marlin to interpolate values to compensate z, and extend it to be able to do a 3x3, 5x5 calibration.

Does that mean that we can have more points in the bed leveling in the future? I’d also like to see the bed come up to temp prior to the leveling process as it changes shape slightly.

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If 3x3 calibration points can fit most of our requirement, we won’t make the process unnecessarily complicated and time consuming. The bed temperature issue is not easy if you don’t get the power supply swapped.

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I’m also having serious problems with the auto leveling. It worked fine my very first print, now every print the first layer is too low.

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Can it be made an option for users to choose between a 3x3 or a 5x5 matrix of calibration points. I have to agree, I am seeing problems with calibration and I would choose to use a 5x5.

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I think first thing to solve is correctly working calibration (initially and quick), no matter if 3x3, 5x5 or anything else.
=> hard hitting bed

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Hello, Are you sure that the Z offset is reset ?. I had encountered the fast calibration running into the bed at station 5 of 9. I found the post in this forum to physically adjust the calibration sensor this allowed the fast calibration. Though when it was time to print the nozzle was a little over 2mm above the bed. I paused and set the Z offset which allowed the print to complete. I then tried reprinting the same item a second time. I noted in the display Z offset had returned to 0 so added the same value I used for the first print but this time the head buried itself into the print bed. So while the display had showed no offset value it looks like the firmware may have retained the original value so when I set it a second time it caused the failure.

As @parachvte mentioned above, the Z offset that you change while the print is running is only kept for the current print. The Z calibration that is set at the end of the 3 x 3 matrix is saved. I have heard many people say that their calibration has not been consistent from one print to another meaning the print right after a successful print.

What I have been doing is bump the Z offset up a couple of .05mm’s worth at the very begining and then while the skirt is printing, bump it back down as needed. Sometimes I have to bump it up even more. You can kind of get a feel by looking at it whether is is squishing down too much or not squishing down at all. Sometime it doesn’t even contact the bed so I have to bump it down a number of clicks.

Eck, yah, but doesn’t this defeat the purpose of having auto leveling? At least with the Snapmaker 1 you could calibrate it and only recal if you remove module or really struggle to remove a print…
At this point I’d rather have it back the old way. =(

We also saw cases with calibration problems, as far as I can see it’s not the problem of using 3 x 3 or 5 x 5 points. We’ll see what the problem really is, then fix it.

My bed is not flat so a larger set of data points may help the underlying issue.

There is more than one problem here, 1) the beds are not flat and a larger number of check points would fix or greatly help that. 2) Some people are seeing the z height jump around and not be consistent.

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And 3) sometimes it didn’t work correctly (auto cali before printing) - for me one of the critical points!

adjustable calibration

  • before print on/off (if an initial calibration is done
  • with heated bed on/off
  • 3x3, 5x5, 7x7, maybe more options (for small prints in the middle i can choose what i have to calibrate), best solution, software checks the size and location of print and choose the best routine (nr of points and location)

Maybe with a menu at sm and/or luban, additional with m-codes.

Is no one else able to disable the quick calibration that runs before the print starts like I am able to do?

How do you go about disabling the quick calibration DroneOn? I’ve been having the same autolevel issue error (hot end digging into the bed because the sensor isn’t responding). I disabled the auto bed level function and did a manual level, but it still tries to quick calibrate before the print. I don’t see a setting on the touchscreen to disable it and I haven’t found a place in the Snapmaker Luban software that allows you to edit the actual code to manually remove that autolevel line.

I’m going to try a print using my Simplify3D software this evening and see if I can get a decent print using that and a manual bed level, but it would be nice to do it all from within Luban.

This is on the firmware rev as I received it in the box. Controller v1.6.0.0 and touchscreen v1.5.2.1

Thanks! I don’t remember seeing that on my settings page but I’ll check again when I get home tonight.