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I can't seem to get my bed level enough  

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Maria Irina
(@maria-irina)
Member
I can't seem to get my bed level enough

Hello, I have a MINI+, but my experience with 3D printing is limited. I got the MINI because Prusa printers are praised as being "ready out of the box", but so far, my experience has been not so good...

I don't know why, but my bed leveling always seems off. I tried adjusting the SuperPINDA sensor to lower than the tutorial recommends (after seeing a post about it), I followed the squaring tutorial two times (the last time with actually good tools, a digital caliper and a carpenter's square) but the mesh data is always weird.

I had soo many problems related to getting the mesh data out, but thankfully a software update solved them all (if anyone's wondering, I was getting 15 values outputted instead of 36 I get now). To get the data out, I am using Pronterface and sending the G29 T1 command (G29 to trigger the leveling process and G29 T1 to get the actual values). I put the plot points in an OpenSCAD script I got from the Merlin repository.

I hope I didn't bore you too much, I'm putting all the details in, in hopes I can help someone frantically Googling my same problems. 

To get to the point, here is a picture of what my mesh looks like right now and below are the values that Pronterface spit back at me.

[0.019, 0.029, 0.164, 0.321, 0.250, 0.294],
[-0.003, 0.070, 0.142, 0.201, 0.187, 0.174],
[0.101, 0.111, 0.121, 0.081, 0.125, 0.169],
[0.107, 0.122, 0.137, 0.064, 0.047, 0.031],
[0.316, 0.185, 0.054, 0.032, 0.005, -0.023],
[0.232, 0.247, -0.030, 0.001, -0.038, -0.054]

 

I have also tried a "leveling patch" test, basically 4x4 squares (1 layer high) and here are photos of one of the tests. I added some sharp lighting because the camera wasn't picking up the surface details. Yes, for most of them my nozzle is too low (a bit exaggerated by the light I might say), but for patches 8 and 12 (and 4, but you can barely see it in the photo) the nozzle is too high! I calibrated the Z offset looking at patch 13. Even if for most of them the nozzle is too low, there are better and worse cases, which are the source of my frustration. From what I understand, the mesh bed leveling should make them all look almost the same, right? 

I can't figure out if I need to square my printer better or try loosening/tightening some screws on the bed surface itself (I read this idea somewhere on the forum I think) or even try the silicone mod, which frankly looks like soo much effort. I just want to get a decent enough first layer... Do I just need to resort to masking tape under my low corner and hope for the best?

This topic was modified 3 months ago 2 times by Maria Irina
Posted : 09/12/2023 1:26 am
stickhog
(@stickhog)
Active Member
RE: I can't seem to get my bed level enough

I found the silicone mod to be the single most effective way of leveling my Mini bed. It was a significant improvement once I installed the mod, which was easier than I thought it would be. But, be aware that the calculation tool webpage for that mod is not currently compatible with the new bed mesh process in firmware 5.1.0. In other words, do not install the silicon bed mod if you are on firmware 5.1.0 as you won't be able to level the bed afterwards, and you will have to because it will likely be significantly changed after installing the mod. The developer is aware of the incompatibility but an update isn't available yet. But if you're still on firmware 4.4.1 or earlier, you'll probably see a significant improvement once you install that mod. 

Also, remember to allow the bed to warm up and stabilize for several minutes before running the mesh. I've found that I can get variation in the mesh measurements for the first 5-10 min after the bed warms up as the entire assembly stabilizes at the higher temp.

MINI+, semi-assembled, March 2022, Octoprint

Posted : 12/12/2023 3:26 am
Felix91
(@felix91)
Member
RE: I can't seem to get my bed level enough

Hi all,

I had similar problems and here is what I did. Please do not be afraid of all the following points, it seems to be more complicated when you are reading all this but in the end it is quite easy and gives a satisfying result. From my own experience I can tell, trying to find other ways give you more headaches 🙃 

  1. Squaring your printer
    https://help.prusa3d.com/article/squaring-your-mini_158518
    1. A bit tricky is the "XZ-axis correction". Ask a friend to hold the Z-axis in place when you found a rectangular orientation to tighten the screws or use spacers to hold this position (I prefer to use spacers, because there is no remaining movement at all). Ideally use a carpenter's square. 
  2. Silicon bed level mod
    1. As I updated the firmware already to 5.1.2 I had to downgrade to 4.4.1.
      1. Firmware can be found here
        https://help.prusa3d.com/downloads/mini-2/firmware
      2. How to downgrade can be found at following link at the end of the instructions: "Alternative method - older firmware release". One note which can help you there and I had to find out: "Push the reset button, immediately followed by double-pressing the selector knob." --> Push and RELEASE the rest button (do not hold the button), then just press several times the selector knob/wheel works best.
        https://help.prusa3d.com/article/firmware-updating-mini-mini_124784?_gl=1*1i3doa4*_ga*MzM0Mjk2ODkyLjE3MDM2MTQ3ODk.*_ga_3HK7B7RT5V*MTcwNDQ3Mjk1NC4yNy4xLjE3MDQ0NzQzNjUuNDMuMC4w
    2. After the downgrade you do not have to adjust first layer or anything as you just want to use the downgrade for bed leveling with the web tool using following instruction:
      https://github.com/bbbenji/PMSBLM
    3. If you found a setup you are happy with, just update the firmware to the latest one using once again the instruction from Prusa but now beginning at the top:
      https://help.prusa3d.com/article/firmware-updating-mini-mini_124784?_gl=1*1i3doa4*_ga*MzM0Mjk2ODkyLjE3MDM2MTQ3ODk.*_ga_3HK7B7RT5V*MTcwNDQ3Mjk1NC4yNy4xLjE3MDQ0NzQzNjUuNDMuMC4w
    4. Now calibrate your first layer.

Hope this helps. Please leave a comment if so, so that others may use this instruction, too. Afterwards, happy printing... 🙂 

 

 

Posted : 06/01/2024 8:51 am
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