Prusa Bed Leveling for Dummies

[WobblyHand]

I think I need to go back to square one in my 3D journey. Although my PLA prints came out ok'ish, I believe my print bed isn't leveled all that well. I did the procedure with the zig zag and the small test square. I find that although the square was ok, the zig zag was not uniform in thickness. I see there are test patterns with more squares. Say I print a 5 x 5 pattern, and I interpret the results, then what? Is there a way for me to vary Z for the different squares?

I just moved my printer, so it is a good opportunity to do re-leveling. But as you can see, I seem to be missing some basic concepts on how this works. Can someone enlighten me a bit? Simply printing a pattern indicates the relative levels of the bed, it does not correct the error. How does one correct or offset the error(s)?

 

[Ken226]

I think I need to go back to square one in my 3D journey. Although my PLA prints came out ok'ish, I believe my print bed isn't leveled all that well. I did the procedure with the zig zag and the small test square. I find that although the square was ok, the zig zag was not uniform in thickness. I see there are test patterns with more squares. Say I print a 5 x 5 pattern, and I interpret the results, then what? Is there a way for me to vary Z for the different squares?

I just moved my printer, so it is a good opportunity to do re-leveling. But as you can see, I seem to be missing some basic concepts on how this works. Can someone enlighten me a bit? Simply printing a pattern indicates the relative levels of the bed, it does not correct the error. How does one correct or offset the error(s)?

I'm not very familiar with Prusa, but the process seems similar to other similar printers, like the Creality models. It uses Z offsets to basically, do a virtual level, without physically adjusting the bed.

Is this the procedure you tried?

Bed Level Correction | Prusa Knowledge Base

This calibration is for advanced users only…

help.prusa3d.com

 

[WobblyHand]

I'm not very familiar with Prusa, but the process seems similar to other similar printers, like the Creality models. It uses Z offsets to basically, do a virtual level, without physically adjusting the bed.

Is this the procedure you tried?

Bed Level Correction | Prusa Knowledge Base

This calibration is for advanced users only…

help.prusa3d.com

I'm not quite there yet.

The issue for me is knowing enough to be able to discount somethings and not others. Not all the advice out there is good. For instance, do I need to screw around with extrusion flow or not. There's some sort of test where you feed in (or mark 100mm of filament) and measure what actually got fed in. There's dozens of little calibrations and I simply haven't found a methodical list that takes you from rank beginner with new printer to nicely printing printer. So I just plain don't know where to start... Don't know what's important or not... Don't know what has large effects on things, or stuff that is just a minor tweak. Would be nice to have a check list. The book they give you gives you a universe of stuff, but they don't explain in simple terms a simple formula that is 95% good.

What I just did was print a 75mm x 75mm x 0.2mm square in the center to check thickness. I did 1/2 the square at one z height and adjusted it positive (away) from the bed, because the original looks too close. I need to measure this, waiting for the bed to cool. It is about right after my adjustment.

I also ran the bed visualizer in Octoprint and it says there's a 0.25mm variation in the bed, min to max. Here's a question, can you run the bed visualizer without the steel sheet? Adjusting the bed screws is a pain if you have to swap the sheet on and off.

 

[Ken226]

I was hoping someone knowledgeable with Prusa would chime in, but it's Sunday. Maybe tomorrow.

I can't be certain what the results of running a "visualizer" without the steel liner installed would be. If it uses an inductive probe, and requires the steel for the inductive probe to pick up the surface, the result could be a disaster. I'm not knowledgeable enough about Prusa to give advice on that.



In my experience, a bed that isn't level results in adhesion problems. Either parts lifting at the corners, or sticking too firmly. A Raft can band-aid bed level issues.

The issues I saw in your PETG thread looked alot more like settings, calibration issues than anything to do with the bed.

Perhaps @7milesup can help out. He knows Prusa stuff.

 

[WobblyHand]

I was hoping someone knowledgeable with Prusa would chime in, but it's Sunday. Maybe tomorrow.

I can't be certain what the results of running a "visualizer" without the steel liner installed would be. If it uses an inductive probe, and requires the steel for the inductive probe to pick up the surface, the result could be a disaster. I'm not knowledgeable enough about Prusa to give advice on that.



In my experience, a bed that isn't level results in adhesion problems. Either parts lifting at the corners, or sticking too firmly. A Raft can band-aid bed level issues.

The issues I saw in your PETG thread looked alot more like settings, calibration issues than anything to do with the bed.

Perhaps @7milesup can help out. He knows Prusa stuff.

I did have to move the printer to a different location in the house. I can tell that some dimensions have subtly shifted by the test patch print. The lines were really squished and I had to increase the head height some.

The PLA was set up sort of ok, (before the move) but I can tell from the enclosure that I made there are some issues. My motivation is to get the printer dialed in using the PLA. Then I can deal with PETG. In all of the prints that I have done, both PLA or PETG there was some sort of bed issue. The first layer looks different on different parts of the bed, as if the height was varying. And the bed height visualizer is telling me there is something off. I'm not quite catching onto the order of the calibrations or tests. Like in machining, the order of operations can matter.

 

[Enoch]

Which Prusa? Mini or Mk3s? I have both and an MMU2s.

Also, not sure what you're referring to here? "Adjusting the bed screws is a pain if you have to swap the sheet on and off"? I've never adjusted bed screws on a Prusa.

 

[WobblyHand]

Which Prusa? Mini or Mk3s? I have both and an MMU2s.

Also, not sure what you're referring to here? "Adjusting the bed screws is a pain if you have to swap the sheet on and off"? I've never adjusted bed screws on a Prusa.

MK3S+.

 

[jeffkash]

MK3S+.

I have the MK3S+ and never had to adjust the bed screws either. What problem are you having?
A 3D printer will never be as precise or repeatable as a mill or a lathe.

 

[Just for fun]

Have you completed the XYZ calibration? With no print sheet and just a sheet of office paper. I have did that twice, I don't think I needed to do it the second time.

I also adjusted the Z height a few times and what it sounds like is your's is not low enough. When I first got mine setup, I noticed that the z pattern was not solid. I kept lowering it until I had a solid Z pattern and the rectangular section at the end would come off as one piece.

 

[WobblyHand]

I have the MK3S+ and never had to adjust the bed screws either. What problem are you having?
A 3D printer will never be as precise or repeatable as a mill or a lathe.

Layer is ok on one side and too high on the opposite side of sheet.