Warped bed 🙁
Well, despite my initial success at dialing in the z height, a set of three objects printed over night failed spectacularly. The one at the back of the bed stuck fine, but the two near the front had their corners come up.
Back to square one. I flipped over my sheet to the other side. Re-did the XYZ calibration. Went through several attempts at dialing in the Z height with the live adjust Z height sample from the thread everyone knows and loves. No matter what I did for Z height calibration the first half of the square was always rippled while the second half was fine. It was acting like one part of the bed was higher than the rest by a large amount. So I pulled out my steel ruler...
Did a chat with support about the base issue (prints coming off) and they suggested Z height adjustment and PINDA adjustment, both of which I've done many times. After looking at the photos (both with and without the steel plate) support said my bed is warped and they're sending me a new one.
Anyone else have this on their printer when they got it? I'm glad support was quick to offer to send out a part, but it's a pretty big letdown. I specifically bought this printer given the quality reputation Prusa has and a desire to get printing without having to spend weeks futzing to get reasonable PLA prints.
Re: Warped bed 🙁
The "warped" bed doesnt sound like the cause of your failures, but the z calibration yes. The whole point of the bed leveling is to account for variations in the frame, bed, and sheet. I am sure if a lot of use took a ruler to the bed, it would not be perfect. The smooth PEI is just not an easy surface for some. I had the same issues myself, and never had any issues with PLA on any of my other printers. You need to constantly clean the PEI with 90%+ alcohol and acetone or it looses adhesion. I have since removed one side and applied buildtak, and its night and day. So, just keep in mind, that the new bed might not fix the cause of your failures, but it may fix the z level. I have a feeling the real problem is just poor adhesion in general (and less because of the warping)
Re: Warped bed 🙁
+1 on z calibration. I had a really hard time getting my z offset dialed in properly. The layer lines on the first layer calibration were too thin for me to see if they were good. The bottom of my prints were warping and coming off the bed. I did a live Z adjust while doing a big flat print and was able to get it perfect. After getting it perfect I no longer had warped prints.
Same model with some Z adjustments:
After getting Z dialed in:
Re: Warped bed 🙁
The point of leveling operation is deskewing, the prusa firmware only takes 9 points. This isn't enough to calculate a curve for a warped bed.
Re: Warped bed 🙁
I can confirm that a warped bed will cause such issues and I am disappointed prusa did not fix those issues on the mk3. I have struggled with a warped bed on my mk2 ever since I received it.
I finally got the issue mostly resolved by removing the inconsistent star washers that where between the bed and the brass standoffs. I replaced them with shim washers that I found online ( they where sold for use with RC cars) the back of my bed is still a bit low but the majority of the bed is now printable.
I wish you good luck as I understand the frustration when prints won't turn out right.
I've found that the forum is littered with prusa fanboys who will blame every problem on the user because their printer works great, so take some answers with a grain of salt.
Re: Warped bed 🙁
I agree that my corners lifting during prints are due to bed adhesion problems and that having a proper z height is the first step. I've spent hours trying to get the z height dialed in using the big flat test print from "life adjust Z - my way". Here's an example from this morning before I contacted support:
These are as they came off the printer, printed on the center of the bed. The bottom right corner of each test points to the front right corner of the bed. If I adjust Z height so I don't have ripples on the near corner, by the time it gets to the far corner it's too high and the lines start to come apart. If I adjust to get a proper height for the far corner the near corner ripples like crazy. At one point I had the center looking pretty good at .630, but anything printed on the edges of the bed would get the signature ripples of being too close.
Maybe my expectations are wrong, but when I drop $800 on a printer that comes with a fancy heated bed, fancy steel sheet, and mesh bed correction, I expect to be able to print PLA across the whole bed without having to resort to glass plates, buildtak, glue stick, etc. That's why I bought this printer: so I wouldn't spend my life doing upgrades and hacks to get a good, basic, PLA print.
Re: Warped bed 🙁
The point of leveling operation is deskewing, the prusa firmware only takes 9 points. This isn't enough to calculate a curve for a warped bed.
Agreed, especially when you look at where my bed is sagging. It's between the 9 points. Each of the 9 points correspond roughly to the screw locations, and those screws are all pretty much in the same plane.
Re: Warped bed 🙁
So what did support say? Did they say you're beat or are they trying to help?
Re: Warped bed 🙁
From my original post:
I'm glad support was quick to offer to send out a part
Re: Warped bed 🙁
Ah, I apologize that I missed that. Glad to see they got you sorted.
Re: Warped bed 🙁
I have no idea why they didn't change the location of the measure points to be away from the screws apart from the centre, this would help with the warped beds, as the screws points are going to be in the same plane 90% of the time.
Re: Warped bed 🙁
I have no idea why they didn't change the location of the measure points to be away from the screws apart from the centre, this would help with the warped beds, as the screws points are going to be in the same plane 90% of the time.
A PCB bed will never be glass flat, seems hard to guarantee at manufacturing. but it's lighter and if it's not too severe it works out well. if you get one 100% flat everywhere, you're lucky.. but pretty sure there would be at least some 0.02-0.05mm variances. worth to check the bed for flat before putting it on... maybe the mount points or Y carriage is causing it to warp when mounted...
Also a warped bed with mesh leveling might get your first layer fine but that warp will still be present on a large enough print... how can it physically print the bottom flat? it cant. your part will have the warp in it too. you would need a raft...
Re: Warped bed 🙁
A'ight. New print bed arrived yesterday. Installed it and what a difference. Yes I can still see a faint gap under the ruler on the left, but it's NOTHING like what the original bed did.
Did a z axis calibration then some first layer z height calibration and came up with .580. Worked beautifully, an even layer across the entire 75mm test square. I ran a print last night of a box and, to be absolutely sure, had a 10mm brim. Worked great: no lifting off the bed.
For other reasons I've been messing around with Simplify3D, so this morning I made my own single layer 75mm square, sliced it in S3D, and printed it out. Even better. Aside from a small bubble at the end of the loop it's flawless.
So pretty!
Re: Warped bed 🙁
Hi there,
after a year I finally have time to play around with my Prusa MK2.
Sadly, I'm also struggling with a warped bed on my mk2 ... and cannot fix it. It's slightly bend in the middle but more important it looks like I have the rear right corner higher than the others (even after removing the star washer !).
I think they will never send me a new bed as I bought it a year ago or so...
So I'm stuck, only capable of printing small pieces; therefore I intend to dismantle it, and rebuild it with some other washers.
I read keith.m6 used some shim washers and that improved his bed leveling.
Where can we find those washers? Anyone has got a reference or a link on Amazon or equivalent site (I'm living in Belgium)
Thanks for your help.