Significant glass delamination started occurring in last month

[CTotten 18]

I have been using an S5 for about 2.5 years now (using two S5 Pro Bundles for the last year).  Since I got the first S5, I have been using basically the same glass print bed for all our prints.  Our original S5 has about 6000 operating hours on it, and our newer S5 has about 2000 hours on it, so they have been used quite a bit.  Overall all of that time, I have had a couple of small glass delaminations occur, but we were basically still using the original glass beds.

I started using Vision Miner's Nano-Polymer Adhesive about a year ago, because it held both the CPE that we print 95% of our jobs with, as well as BreakAway.  I haven't had any issues with it, except that it holds the BreakAway really well, meaning I have some scraping to do between prints.  In most cases, the CPE only prints just pop off after they cool down.

 

Anyway, about a month ago, I came into work and found that both machines with finished prints, but when I removed them, significant portions of the glass delaminated with the print.  I thought it was odd, but the glass was old and had a few chips in it, so I thought it just finally gave out.  So I pulled out the brand new spares.  The few days later, the same thing happened with brand new glass.

- I reperformed the manual leveling on both machines, thinking maybe it was a thermal issue with colder weather causing the first layer to print too close. 

- I also switched over to using the UHU stic provided from UM on the CPE only prints.  We got 4 new pieces of glass from our distributor, and got back to work. 

 

Today, I come into work and find both prints again caused significant delamination.  One print is about 8" x 8" square with a solid bottom layer.  The other is a 8" diameter circle, with about 50% of it being a solid bottom layer (with some openings).  So they are both "large" prints with solid bases.  But I have literally printed hundreds of items like this without an issue.

 

I am running 6.5.1 on both units, and have not updated firmware in about 2 months.

 

Any ideas on the causes of this?  I have shreaded 5 sheets of glass (at about $45 each) over the last month, after not losing a single one over 2.5 years.  I am printing the same things, with the same materials, using the same techniques that I have been using for a long period of time.  But something seems to have changed.

[bearsfeat 0]

This is quite odd - for me - in that I have been printing on my UM3 for several years (about 4 - maybe 5? time flies) - and I just this week started seeing this.

 

I have printed maybe 90% PLA over this time, I have printed only one full spool of CPE about 2 years ago. I have printed maybe a half spool of ABS and about three weeks ago started printing PETG for the first time. After my 2nd full spool of PETG, I got significant glass delamination (tagging for searchers: glass peeling, cracking, chipping, separating)

 

I use hairspray exclusively and always have. I have finished my PETG project for now and an currently printing PLA again. I offer you no help, only solidarity. Hopefully someone picks up on his thread and offers a cause / solution. (It is the cause that has e baffled.)

 

 

[UlrichC-DE 109]

I also have this problem. However, I only know it with printers that are in the cold. If the objects are large and higher than one cm.

Therefore I had explained it in such a way. The object cools down faster in the cold and contracts against the thermal expansion. The contraction varies depending on the material. And the greater the temperature difference, the greater the effect.

In addition, there is a kind of leverage effect at cold temperatures. Because the object does not cool down evenly, but in the upper area first. The residual heat of the plate and, in particular, the lack of air circulation between the plate and the object prevent uniform cooling. As a result, the surface of the print object cools down and contracts. The edges are torn from the plate and the walls and structures of the object act as levers.

Because the plate is still warm at the time and there is good object adhesion, it cracks.

At warmer temperatures, the effect is diminished. Even if you take the plate out of the printer immediately after printing, or even put it in the refrigerator, the effect is not as strong.

 

 

[geert_2 558]

Moisture in the air might also play a role: when printing PLA on bare glass, it sticks way better in very dry air, like in freezing weather, than in very moist air, like in rainy summer weather. Not sure if this effect also works when using glue...

 

Also double check, or tripple or quadrupple check, if nothing else has changed in your setup? Such as different calibration, different temperatures or speeds of the first layer, different filament (or even a different color or batch),...?

 

[CTotten 18]

On 11/29/2021 at 6:43 AM, geert_2 said:

Moisture in the air might also play a role: when printing PLA on bare glass, it sticks way better in very dry air, like in freezing weather, than in very moist air, like in rainy summer weather. Not sure if this effect also works when using glue...

 

Also double check, or tripple or quadrupple check, if nothing else has changed in your setup? Such as different calibration, different temperatures or speeds of the first layer, different filament (or even a different color or batch),...?

 

Thanks.  I was wondering about the humidity, as it has been pretty dry recently, even for a typical November here.

 

I have switched to using the the UM supplied UHU stick, with a clean glass and a fresh coat of UHU prior to each print, and I have not had the issue over the last week.  I did redo the manual bed leveling when this first started happening, thinking that a cooler temp (at night, since they cut the heat back) caused some contractions of the long Z axis components caused the first layer to print too close to the glass, but that didn't seem to change anything.  And I run two different UM S5 Pro Bundles (one old version and one new version), and they both started doing this at the same time.  So in my mind that eliminates the possibility of an issue with a single machine.

[CTotten 18]

Just an update.  This is still happening.  I have went through 6 total pieces of glass over the last 4 or 5 months.

 

I also noticed that the first few layers of some of my prints appear to deforming, more than I ever noticed before.  Not just the typical elephants foot on the bottom layer.

 

I also noticed that UM increased the default bed temperature for CPE "recently".  I just noticed that the bed temperature is now set a 85C for CPE prints.  My memory was that it was 75C prior to this change.  Does anyone know when this change occurred?

 

My thinking is that the increased bed temperature (which I have never adjusted from the factory defaults) is possibly the culprit for the delaminating glass, as well as the deformation on the bottom few layers of the prints.  They say the change was for "increased bed adhesion".  But my delaminated glass says I have too much adhesion now, and the deformed bottom layers says the glass (and material) is staying too warm during the print, and deforming under the weight above on large prints.

[CTotten 18]

I looked through my records:

 

Sept 20, 2021:  I updated CURA to version 4.11

Oct 16, 2021: I requested to order new S5 print bed glass panels through our purchasing system.  This was after a few sheets got shreaded during printing.

 

So my working assumption now is that when I updated to Cura 4.11, I got the update that changed the CPE print bed temp to 85C.  This increased temperature is the cause of the bed delamination issues.  I am not currently printing big jobs, but I will be overriding the print bed temp setting back down to the 75C range for S5 prints to confirm this was my issue.

 

I also searched through the Cura update notes on the UM website, but couldn't find which version added the CPE temp change.  But I know it was put into the code (through GitHub) around March 2021.

[arj3090 2]

I recently ruined 4 glass plates in about a 3 week span by delamination. It was mostly with CPE+. I tried no adhesive, glue stick, and Vision Miner Nano. None of them stopped this from happening.

[glx 27]

I use Magigoo glue for CPE and didn’t have problems with it. 
but I also killed two glass plates (one with ABS and one with CPE) when I didn’t cover the surface completely. 

[geert_2 558]

For PET, I never use any bonding, I print on bare glass, with cooling fan off or very low. But I do use my "salt method" prior to starting a print: wiping the glass plate with a tissue moistened with salt water.

 

For PLA, the salt method greatly increases bonding when the glass is hot, and when cooled down, models pop off by themself. For PET, the salt method *reduces* bonding a little bit (compared to printing on bare glass, or glue), but it makes the models pop off after cooling down too. Without chipping the glass.

 

So, expect bonding to be a bit *less strong*, and carefully test if it works for your models and materials. Stay with the printer, and watch if corners do lift, or if the model comes off while printing, as this could ruin your print head.

 

For me, the salt method works very well with long low models, like rulers. But it is not recommended for thin tall models like lantern poles.

 

Try with a test model that is very hard to print. You could print the exact same model multiple times on one print bed in one run, each bonded with a different method: glue stick, dilluted wood glue, salt method, bare glass, hair spray,... And then compare how each of these behave.

 

I used to run my bondingtests with models like these inverted prisms:

 

 

For an old explanation of the salt method, see here:

https://www.uantwerpen.be/nl/personeel/geert-keteleer/manuals/

 

 

[CTotten 18]

On 4/7/2022 at 5:43 PM, arj3090 said:

I recently ruined 4 glass plates in about a 3 week span by delamination. It was mostly with CPE+. I tried no adhesive, glue stick, and Vision Miner Nano. None of them stopped this from happening.

I had been using the Vision Miner Nano Polymer adhesive for over 2 years with excellent results.  I have printed over 100 full spools of CPE.  But I am not very confident that this under the radar increase in bed temp is the cause of my issues.

 

What frustrates me is that I use "profiles" that I set up.  Apparently those profiles aren't as "secure" as I thought.  I obviously only "locks" settings that I have changed from the default.  And if the default value is changed in Cura, then it changes it in my profile with no notification...