Uneven bed level. Cannot adjust Z
Hi everybody, new Prusa owner here. I have built my kit few days ago. No major issues during the build. Manage to do the XYZ calibration with the nozzle dipping only one crater into my heatbed at the very last point (#9), solved by lowering the PINDA. Did the first layer calibration using the V2 file and started doing some test prints. And everything was pretty good right off the bat. Did a prusa logo, a pretty decent Benchy and another random model with supports. So far so good.
Then I wanted to make sure the Y-axis belt attachment was tight since I saw some random wobble in the Benchy, so I SLIGHTLY tightened the two screws under the heatbed and started the second Benchy. After half hour the first layer came off and spaghetti for everyone. I figured I had to recalibrate the first layer, but from this point on it has been a disaster.
The V2 calibration seems to show that the first corner (up-right) is way closer to the nozzle than the rest of the bed, especially the middle. It looks like the heatbed is not leveled and the bed leveling does nothing to compensate for it. I tried realigning the whole Y-axis, but no success. I reattached the heatbed and did the full calibration several times. The result is always exactly the same, like shown in the pictures.
Adjusting the live-Z to get a good first layer in the center makes the nozzle way too low in the corner. Also the initial cleaning line that the printer makes at 0,0 looks very fat as well.
https://goo.gl/photos/aFioEXy5vudYvJuZ7
Anybody has any idea what it could be?
Re: Uneven bed level. Cannot adjust Z
I have found that if you make a mechanical adjustment you need to re-run the XYZ calibration so the machine knows where all the points are.
I have found that adjusting the Live Adjust Z using the V2 calibration file to be a hit or miss art-form (mostly miss in my case) as I did not know how to get the value in the right range before looking at the print and adjusting, and I could not reliably see the single line thickness to understand if it was squashed down enough to contact the adjacent layer.
The more reliable method (to get it close enough for a print to see, and a more reliable calibration file) can be found here:
Try all the steps in order.
If that does not help, please comment back here and we can see what we can figure out.
Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage or loss. If you solve your problem, please post the solution…
Re: Uneven bed level. Cannot adjust Z
Thank you for the help. I forgot to mention that I ran the full XYZ Everytime I made significant adjustments.
I didn't have any issue using the V2 before, I was actually pretty happy with the evenness of the string. It seems that the printer now thinks that corner is way lower than it actually is. I will try the V4 later but I'm afraid it will yield similar results. perhaps I'll do a factory reset and XYZ beforehand since I've seen someone reporting it helped.
Re: Uneven bed level. Cannot adjust Z
Okay, so.. I redid all the calibration and printed the square from the thread you indicated. The result is not great and kind of confirms what I thought. I started at -0.730 and then moved up to -0.790 with a small pause at -0.760 along the diagonal. You can see in the pictures the lines are very uneven, especially at the top right corner, where the extrusions actually overlap and created a small ridge... I am open to suggestions at this point as I have exhausted all ideas...
Re: Uneven bed level. Cannot adjust Z
Hard to tell from a photo, but it looks like you have the Live Z Adjust value too low, and the nozzle is plowing through the filament.
When you did step 3 of the instructions, what Live Z Adjust height was set when the paper began to drag?
Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage or loss. If you solve your problem, please post the solution…
Re: Uneven bed level. Cannot adjust Z
If I use that method and calibrate using the procedure in step 3, I get that the paper starts dragging in the middle at -1.250mm (!!!). I tried moving the Y down a little bit without moving the Z and it starts dragging when it gets 1 inch towards the top, so I didn't feel comfortable starting a print with that setting since it would most likely scratch the heatbed. The prints you saw where at -0.790. I should mention that I might have a weird PINDA. During the first ever calibration it dipped into the heatbed at point 9, and the online support told me to use the tip of the ziptie instead of the center to adjust the PINDA to be closer to the bed. Any advice on how to proceed? At this point I feel the bed might be seriously out of level and I might have to try disassembling the Y-axis and put it back.....
Edit: By holding the extruder/nozzle in place and manually moving the bed along the Y-axis I can clearly tell by looking from the side that the nozzle gets further away from the bed in the center and closer towards the edges. It really looks like the heatbed is warped, but I don't think it was at the beginning... I did try to loosen the heatbed belt screws in case those were too tight and were pulling the bed down in the middle, but I can't unscrew more without the belt attachment becoming loose...
Re: Uneven bed level. Cannot adjust Z
take you a little bit of time and read this thread and that one.
follow the hints, recommendations and instructions that you'll find inside these two threads.
dem inscheniör is' nix zu schwör...