Warped glass on the UM3

[picaschaf 3]

Hi,

I have a very strange problem since yesterday. From one print to the next the nozzle scratched on the glass very badly - but only in the middle part of the bed.

After checking all screws, axles, etc. I removed the glass plate and after checking it with 2 different rulers I found out that it is warped from the front to the back. But this must be happened just from one print to the next because yesterday morning everything was fine and the print I started in the evening was messed up.

Is this normal (to compensate the heated bed, or wear)? Does it go away with time if I flip the glass? Is this a warranty case?

Best regards,

Alexander

[neotko 1,417]

Is this normal (to compensate the heated bed, or wear)? Does it go away with time if I flip the glass? Is this a warranty case?

 

That's a good question and I personally don't have the answer. I would ask the reseller. Also it could be interesting to have that answer, so when you get it can you forward it here also for other users?

[picaschaf 3]

Little update. I made a video and some photos to prove the warp and then cleaned the glass, turned it over and did a new manual calibration. Then I started the same print as yesterday and no scratching and (at least in my opinion) a nice finish. The stringing and brim blobs are "okay" for now as the nozzle is a little too hot and I didn't apply hair spray as I do it normally (just for this test).

Do you think this is a good calibration or should it be higher/lower?

While observing the behavior of the turned over glass I will contact my reseller and share his response with you.

[neotko 1,417]

That looks like a very good calibration.

[SandervG 1,521]

I would be surprised if the glass indeed got bent due to heat. Unless you have secretly been printing on 500º/600ºC?

Could it be that you have been printing smaller objects and you just did not notice?

I would indeed contact your reseller and see if you can replace it if it is indeed bent.

What is the thickness of the first layer you are trying to print?

Edited January 5, 2017 by Guest

[picaschaf 3]

I would be surprised if the glass indeed got bent due to heat. Unless you have secretly been printing on 500º/600ºC?

Could it be that you have been printing smaller objects and you just did not notice?

I would indeed contact your reseller and see if you can replace it if it is indeed bent.

What is the thickness of the first layer you are trying to print?

 

I hope not

I don't think that the glass was warped already. Yesterday everything was fine and now this. When I look at the nozzle while building the first layer (140% height, 100% width, base height 0,2mm using Simplify3D) I can clearly see that the nozzle is very close to the bed on one side, and on the other side it is nearly 1mm away from the bed.

[picaschaf 3]

I went out to buy a new original Ultimaker glass and I am shocked. All four glasses at the seller are warped O_O And, not a little bit. 2 of them are actually far more warped (>2 mm) than my current one. Now I've bought the one that has the least warp but this is still causing issues.

Today I also updated to the current firmware with the new calibration mechanism but this changed nothing. The machine still assumes a flat bed.

Is there any unwarped/unwarpable alternative to the glass for the UM3?

[tomnagel 126]

Did you upgrade your printer to firmware v3.5 already? It contains an improvement to the Active Leveling software, which in some situations will give a more accurate result.

Beware: Active leveling has also been made a little quicker, by starting higher. If you have manually leveled your bed more than 2mm higher than nominally, it fails.

Nominal position: 14mm distance between top of base plate and bottom of heaterplate.

[gr5 2,172]

I believe the new active leveling only takes 4 points on the glass (plus 2 with the second core). So I don't think it will take care of warped glass. Just non-level glass.

I was able to bend my aluminum which corrected for any bend in the glass. Although actually most of the error was in the aluminum in the first place but I think it's worth a shot. It only took one minute.

[picaschaf 3]

I believe the new active leveling only takes 4 points on the glass (plus 2 with the second core).  So I don't think it will take care of warped glass.  Just non-level glass.

I was able to bend my aluminum which corrected for any bend in the glass.  Although actually most of the error was in the aluminum in the first place but I think it's worth a shot.  It only took one minute.

 

I don't think that the little aluminium sheet is capable of bending the glass back in shape Also my printing results show that this is not happening.

[picaschaf 3]

Did you upgrade your printer to firmware v3.5 already? It contains an improvement to the Active Leveling software, which in some situations will give a more accurate result.

Beware: Active leveling has also been made a little quicker, by starting higher. If you have manually leveled your bed more than 2mm higher than nominally, it fails.

Nominal position: 14mm distance between top of base plate and bottom of heaterplate.

 

I have the most current one the UM3 offers me to update to. But the only change I saw is that now the active leveling also does 3 points for the second print core. But as my glass is warped this is not enough for an accurate calibration.

After manual leveliing the nozzle at least doesn't scratch on the glass, but the prints are useless.

As already seen with a different part (the pink one above) this part shows the same behavior. In the front right (where the glass is flat) everything is fine. In the back left the nozzle is too far away and in the middle it nearly scratches the glass again. Yes I am printing very near to the clip, but the area where you see the lines not touching is away from the clip where the head doesn't touch it.

And I've written before, yesterday I was at a local seller - all four glasses he had in stock were warped, some even more than mine. He tested them himself and I testet them also.

[neotko 1,417]

[i don't think that the little aluminium sheet is capable of bending the glass back in shape Also my printing results show that this is not happening.

 

Yeah your problem might not be that. On my beta um3 I fixed the deformation points by pressing the points on the metal that where curved and now my first layers are perfect. Ofc that isn't a method I would suggest to a new buyer. But I did that also long ago on one of my umo+

https://ultimaker.com/en/community/10335-glass-plate-not-flat#reply-115893

Ofc the problem to do it correctly on um3 is that you don't have easy access to the gcode to see where the nozzle goes up/down on a banana bed. I did it using the command_util.py that's on the linux of the um3. To access it you would need to ssh root@yourip then pass ultimaker, and cd ../usr/share/griffin then 'python3 command _util.py'

With this command util you can sendgcode G28 to home all, and G0 Z15 moves the bed near the cores. Then you can bit by bit getting closer to the nozzle. This way moving the printhead you can actually check the points where it's curved.

Ofc, maybe your problem isn't the plate but just the glass. Also check that the ruler is really straight comparing it, for example, to a x/y shaft straightness.

[picaschaf 3]

 

[i don't think that the little aluminium sheet is capable of bending the glass back in shape ;)Also my printing results show that this is not happening.

 

Yeah your problem might not be that. On my beta um3 I fixed the deformation points by pressing the points on the metal that where curved and now my first layers are perfect. Ofc that isn't a method I would suggest to a new buyer. But I did that also long ago on one of my umo+

https://ultimaker.com/en/community/10335-glass-plate-not-flat#reply-115893

Ofc the problem to do it correctly on um3 is that you don't have easy access to the gcode to see where the nozzle goes up/down on a banana bed. I did it using the command_util.py that's on the linux of the um3. To access it you would need to ssh root@yourip then pass ultimaker, and cd ../usr/share/griffin then 'python3 command _util.py'

With this command util you can sendgcode G28 to home all, and G0 Z15 moves the bed near the cores. Then you can bit by bit getting closer to the nozzle. This way moving the printhead you can actually check the points where it's curved.

Ofc, maybe your problem isn't the plate but just the glass. Also check that the ruler is really straight comparing it, for example, to a x/y shaft straightness.

 

Thank you for sharing your experience on that issue I will work through it later that day and have a look what I can do on my UM3.

I've already checked my ruler and used a different ruler, that is not the issue. And the glasses from my seller hat a warping that is even visible to the naked eye. If you want I do a short video on both glasses I currently have.

But the thing I habe with a new calibration is, even if I have the exact shape of the warping, will the UM3 firmware be able to handle it correctly? At least the standard leveling with 3 (or 2x 3) points is not even mathematically able to compensate warping. 3 way calibration is only able to compensate misaligned bed screws in the plane.

[picaschaf 3]

@neotko I had a quick look on your posting and I've already found it when searching here for warped glass. But I discarded it as my solution as on the UM3 there is no screw between the glass and the bed anymore. You can see the new construction in the 2nd of 3 pictures in my last posting with the ruler picture first. Also the glass is much more bent than the one in your posting inside the printer as well outside the printer.

Also it should not be able to bend borosilicate glass

Edited January 7, 2017 by Guest

[neotko 1,417]

Indeed it should not. And maybe my problem was the metal and not the glass. But it did work and on my beta um3. Indeed the screws stuff, but that also wasn't the problem on my umo.

Anyhow I would ask for a fix since you got a new product and you paid for it good money

[picaschaf 3]

Indeed it should not. And maybe my problem was the metal and not the glass. But it did work and on my beta um3. Indeed the screws stuff, but that also wasn't the problem on my umo.

Anyhow I would ask for a fix since you got a new product and you paid for it good money

 

Yeah, I'm in contact with the UM support and my seller. But I would like to see a definite solution, not sending 10 plates around the continent and luckily maybe there is one that is ok. Like I said, at least the one seller I had in my driving range yesterday, had his store full of warped glasses.

[StephanK 30]

Picaschaf,

i have 3 UM glass plates now and all of then are warped, some more, some less. One that came with the printer, one from conrad.de and one from 3dmensionals..

My solution was: checking the yellow pages for a local business selling glass. It ended up a tiny big thicker (4mm), doesn't have the spiffy rounded edges and set me back 80,00 Euros.. but now I got a mostly flat one. I gave up trying to get one from Ultimaker.

[picaschaf 3]

Picaschaf,

i have 3 UM glass plates now and all of then are warped, some more, some less. One that came with the printer, one from conrad.de and one from 3dmensionals..

My solution was: checking the yellow pages for a local business selling glass. It ended up a tiny big thicker (4mm), doesn't have the spiffy rounded edges and set me back 80,00 Euros.. but now I got a mostly flat one. I gave up trying to get one from Ultimaker.

 

Thank you for sharing your experiences! Maybe I'll try this as well. But how thick is your glas? My original glas is already exactly 4mm thick.

At the moment I'm in heavy contact with Tom. It's crazy how seriously the guys @ Ultimaker take this issue. At the moment we are discussing different possible causes. The print problem itself with my original glas disappeared after moving the printer back in room where it was before and after a series of auto and manual calibrations.

It seems that the firmware is capable of working around small warps (like my original glas has) but not big warps >2mm (like my new glas has).

I've got some tests to do from Tom and after we figured out the cause of the sudden nozzle scratch I will update you all in this thread.

[gr5 2,172]

Are you sure the nozzle scratched the glass? Brass is MUCH softer than glass. Even steel is softer than glass and shouldn't scratch it normally. Could it instead be a very very thin layer of pla?

[StephanK 30]

But how thick is your glas? My original glas is already exactly 4mm thick.

The last one from 3dmensionals is 3.7mm, the one from Conrad is 3.6mm, the first one i cannot measure anymore since I stuck a Filaprint plate on top.

[picaschaf 3]

Are you sure the nozzle scratched the glass?  Brass is MUCH softer than glass.  Even steel is softer than glass and shouldn't scratch it normally.  Could it instead be a very very thin layer of pla?

 

No, the nozzle didn't let scratchmarks on the glass, but it touched it so heavily that it made bad noises when the print head moved