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Topic: How warped are your glass beds?

If I do the "printer paper" calibration method, when the three areas over the screws just have the paper drag against the nozzle, the center is so tight I can't get the paper in.  It's making it challenging to get prints to stick well across the whole bed.

How do yours compare?  Should I call support?

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Re: How warped are your glass beds?

awesomeness wrote:

If I do the "printer paper" calibration method, when the three areas over the screws just have the paper drag against the nozzle, the center is so tight I can't get the paper in.  It's making it challenging to get prints to stick well across the whole bed.

How do yours compare?  Should I call support?

There is some warpage on the bed. Could also be your linear rods. Mine on the right is slightly bent. When I rotate it I can see the head move away from the bed by .5mm. The best thing to do is just average so you have the proper clearance in your tightest spots. Those could be slightly lower as long as the filament still extrudes.

Printing since 2009 and still love it!
Anycubic 4MAX best $225 ever invested.
Voxelabs Proxima SLA. 6 inch 2k Mono LCD.
Anycubic Predator, massive Delta machine. 450 x 370 print envelope.

3 (edited by awesomeness 2015-01-06 20:43:15)

Re: How warped are your glass beds?

I'm trying some new adjustments now, similar to what you suggest.

0.5mm (0.020")?  That's huge warping, much larger than mine.  So you can fit roughly 3x extra sheets of paper between the nozzle and bed, in the furthest-away spots?  Mine is more like 0.2mm (0.008" ~= 1 extra sheet of paper) warp.

Unfortunately, I hadn't tested the clearance in the center of the bed before.  So I don't know if it has changed.  Something odd is going on though, because I was getting really good sticking results, and now builds are warping badly, and can easily be broken loose from the bed.

My printer is only a couple weeks old, and has had some discoloration around the heating elements in the bed, since it was new.  I wonder if those couldn't have led to some failures and uneven heating?  Do others see this in their beds?  (Picture attached.)

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Re: How warped are your glass beds?

HI I have the same exact problem. Glass is higher in the middle. And yes my heater was discolored when I got it about 6 months ago.

5 (edited by carl_m1968 2015-01-07 00:55:59)

Re: How warped are your glass beds?

If you notice the thermistor is on the very back edge of the bed. I know glass has pretty good thermal transmission properties but still only stands to reason that the middle will always be hotter than the edges in order for the edge to be the correct temperature. The bed should be designed where the desired temp is measured at the center where the object usually is. I think this design causes the plastic substructure of the bed to warp which intern warps the glass. This also keeps the glass under constant stress which would explain some of the reports of broken glass as well.

The warpage in my right rail only affects the front right quarter of the bed. So far even for prints that go into that region it has presented no real issue. It seems once it is hot my bed actual lifts on that side a bit thus closing the gap more.

Printing since 2009 and still love it!
Anycubic 4MAX best $225 ever invested.
Voxelabs Proxima SLA. 6 inch 2k Mono LCD.
Anycubic Predator, massive Delta machine. 450 x 370 print envelope.

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Re: How warped are your glass beds?

I have the same discoloration.

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Re: How warped are your glass beds?

XYZ has said that discoloration is normal and nothing to worry about.  I have it as well and have no issues.

DaVinci 1.0A with Repetier .92
Simplify 3D
E3DV6

8 (edited by carl_m1968 2015-01-07 03:39:50)

Re: How warped are your glass beds?

mpoffo wrote:

XYZ has said that discoloration is normal and nothing to worry about.  I have it as well and have no issues.

However the fact that uneven heating is evident, the plastic substructure of the bed is warped from that uneven heating and the glass is also being warped by the bed substructure is not normal. If you remove the part of the bed the glass sits in, and put it on a flat surface you will see it is usually warped. This part should be made from aluminum like it is on most other printers and not ABS injection molds.

I mean think about, if the bed is getting hot enough to keep your ABS print slightly hot so it cools evenly and bonds better it only stands to reason that it can get hot enough to warp or stress the ABS support structure as well.

Printing since 2009 and still love it!
Anycubic 4MAX best $225 ever invested.
Voxelabs Proxima SLA. 6 inch 2k Mono LCD.
Anycubic Predator, massive Delta machine. 450 x 370 print envelope.

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Re: How warped are your glass beds?

carl_m1968 wrote:
mpoffo wrote:

XYZ has said that discoloration is normal and nothing to worry about.  I have it as well and have no issues.

However the fact that uneven heating is evident, the plastic substructure of the bed is warped from that uneven heating and the glass is also being warped by the bed substructure is not normal. If you remove the part of the bed the glass sits in, and put it on a flat surface you will see it is usually warped. This part should be made from aluminum like it is on most other printers and not ABS injection molds.

I mean think about, if the bed is getting hot enough to keep your ABS print slightly hot so it cools evenly and bonds better it only stands to reason that it can get hot enough to warp or stress the ABS support structure as well.


You have no argument from me.  I think that is a very valid point.  I was simple responding to the discoloration comment.  smile

DaVinci 1.0A with Repetier .92
Simplify 3D
E3DV6

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Re: How warped are your glass beds?

I replaced the glass on my printbed a week ago and noticed that the middle was quite a bit lower. I had a look at the plastic underlying bed frame and it had at lease 2mm deflection in the middle. It is a very even slope from the corners/edges to the middle.

The replacement bed came with a new plastic bed frame that was straignt. I replaced this as well hoping it would offer more support and straighten the bed.

After a few heat / cool cycles using the calibration process the bed is no longer warped in the middle. I used the auto calibration method and it evened out, but I still had to manually calibrate it to get the head closer to the glass for a reliable print.

The frame support structure has a lot to do with the glass apparently. And as previously posted, it should be made of something that is more tolerant of heat. I imagine that the new plastic bed will warp over time.