Bed leveling either not compensating for or creating bed tilt?
 
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muusecalliope
(@muusecalliope)
New Member
Bed leveling either not compensating for or creating bed tilt?

I had posted about this a couple times on r/prusa3d and nobody really had ideas, so I came here and made an account to see if it would be any different. (I have had this issue for months now, but since it's existed since I built the printer and seems to be related to some hardware problem, this seemed like the best forum. This has persisted before and after firmware update 3.9.0.)

I got a MK3S kit around mid-2019, as the first 3d printer I've ever had/used. A month or 2 after I started with it, after I had gotten more familiar with what is good and bad in a print, I noticed that the reason I was always getting spaghetti monsters before I added a layer of painter's tape and after I went without it for ABS is that extrusion was consistently off across the x-axis of the printer- on the right side it would be almost touching and heavily underextruding, while the left side struggled to adhere to the bed. I didn't find any resources talking about this so I just went through the cycles of all the things I could think that would be going wrong- for a long time I just struggled with using different print surfaces or frequent alcohol cleanings of the sheet or redoing first layer calibration to fix it from an adhesion standpoint; i also tightened the belts 3+ times, I changed mesh bed leveling to 7x7, I redid the wizard so many times, I did the nylock mod, and now finally as a last-ditch catch-all I took the printer apart down to every frame extrusion and put it back together.

I calibrated the first layer until it looked good, and then started a corner calibration test, and... now not only is the x-axis off (and in the opposite direction, no less!), but the y-axis as well, and even more severely... so I definitely did something. The thing I'm stumped on is that if it's a hardware issue, the mesh bed leveling should be automatically compensating for it, right? and doing the nylock mod relies on readings FROM the probe, which I got to +/- 0.01 mm max and which was also very repeatable over the multiple G81s I issued. So the probe is very confidently reading a flat bed relative to itself, multiple times... and then as soon as it starts a print there is some kind of tilt that did't exist there before.

Honestly, the way that Prusas are described by everyone else who has owned one as the epitome of automation, that you can set the printer up and never have to tinker with it again, has been extremely frustrating, especially when this is an issue that renders my printer nigh unusable and nobody can think of what could be causing it. Any suggestions at all are desperately welcomed.

Posted : 22/06/2020 10:12 am
bobstro
(@bobstro)
Illustrious Member
RE: Bed leveling either not compensating for or creating bed tilt?

Have you been in contact with support via chat? If not, log into the online store and look for the chat option there.

Is it possible your build is skewed? It sounds like the PINDA thinks everything is level. I don't have experience with this problem, but it sure sounds like something fundamentally wrong mechanically based on the way the problem has shifted around.

My notes and disclaimers on 3D printing and miscellaneous other tech projects
He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan...
Posted : 22/06/2020 1:50 pm
Walleye
(@walleye)
Eminent Member
RE: Bed leveling either not compensating for or creating bed tilt?

Hi,

I haven't had your issue, but perhaps a couple of ideas to maybe consider.

Are you sure your frame is square and level as the assembly instructions stress?

Are all the parts still snugged up and properly tightened?

Have you moved your machine lately? Or has it been banged a bit?

Is the surface it sits on flat? (Level is nice but not required. Just flat)

Posted : 22/06/2020 3:41 pm
SugaryPlumbs
(@sugaryplumbs)
New Member
RE: Bed leveling either not compensating for or creating bed tilt?

I'm having what I believe is the same problem. Motion on the printer causes progressively worse tilt over time. It is very repeatable by simply running mesh bed leveling. A 7x7 calibration adds about 0.1mm of tilt each time, always with the right side of my bed going lower (though in reality it is the right size of the X axis that is higher).

I can physically compensate for this by turning the right Z axis motor by hand to bring it back to level. It actually is the Z motors not being in sync with each other, though whether this is a software issue or mechanical I cannot say for certain. The motors turn easily without binding, but I have also tried with significantly higher motor current settings to overcome any possible binding issues. No success there.

This isn't an issue with single item prints, since I can manually level with the motor and make the first layer work that way. However, if I fill the bed with small objects (like the Tippi Tree leaves) then the printer becomes unusably out of level before it finishes half of the first layer.

Posted : 26/09/2021 4:22 pm
Dan Rogers
(@dan-rogers)
Noble Member
Multiple possible problems, no stable starting point

Something changed ... so I changed more stuff, then it kept changing more, so I changed even more stuff.  can you guys help me get it working?

Honestly - first guy, post some pictures, and work on one problem at a time.  "Now X is off and Y is off too" - could mean anything.  Off what?  

Second guy - you either have a bad motor (losing steps) or your frame is loose.

 

Posted : 27/09/2021 4:11 am
Tracy
(@tracy)
Trusted Member
I'm having the same issue

If I don't change my Live Z, prints on the left have a rough bottom (not enough squish) while prints on the right have a smooth bottom and elephant's foot. It's bad enough that I have to change the Live Z depending on which side of the plate I'm using. I got my MK3 in May 2021 and it's been an issue since day 1. I just finished chatting with Prusa support and their only suggestion was to use 7x7 mesh bed leveling which makes no sense because I'm not experiencing gaps. It's a gradual tilt from left to right. 3x3 should compensate for this.

I just found this knowledge base article. Guess I'll have to spend some time doing trial and error printing until I fix this.

Posted : 01/10/2021 7:11 pm
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