Using the correct side of an Ultimaker glass plate

[SandervG 1,521]

Hello! 

You may have heard stories about glass plate having one side which brings you slightly better adhesion compared to the other side, or perhaps you have experienced this first hand yourself. 

Allow me to provide you with some background information and some instructions to figure out which side you should be printing on and which side you should use if you want to add an adhesion sheet. 

 

The difference is first introduced during production. When our glass plates are being made, near the end of the production line there is a hardening process. During the hardening process, the plates float on a layer of tin and are heated from above. This creates a difference between the two sides. 

 

There are two main factors that ensure good adhesion to the glass plate: wetting and flatness.
Wetting is the ability of a liquid to maintain contact with a solid surface. Lower surface tension means better wetting. The non-tin side (i.e. upside during the hardening process) has a lower surface tension than the tin side. Therefore the non-tin side is recommended to print on. 

 

If the sticker that is on your glass plate fell off, you can do a simple small test to identify which side is which by placing a drop of water on both sides of the glass. (Not at the same time though). The non-tin side, the side you want to be printing on, is hydrophilic and the water disperses.

On the tin side, the water will form a droplet (this side is hydrophobic). If you want to use an adhesion sheet, it is recommended to stick it to this side. 

 

 

Hope this helps! Let me know below if you have any further questions! 

[PaulK 14]

Wow, I had absolutely no idea that the two sides of glass were not the same. That is fascinating! I guess my "other" plate which has a chip out of it (CPE, I'm looking at you. I think it was you) should be best kept for use with adhesion sheets.

 

I often print with a thin coat of PVA (ok, actually hairspray). Does this negate the difference? One would think so, but since I had no idea about the glass, now I doubt everything 🙂

Edited January 25, 2019 by PaulK

[XYZDesignPro 70]

Here's a link to just about everything and anything you ever wanted to know about tempering glass:

 

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=10&ved=2ahUKEwinwO21tIngAhUFN30KHbVTB8gQFjAJegQIAxAC&url=https%3A%2F%2Fbelglas.files.wordpress.com%2F2016%2F01%2Ftheglasstemperinghandbook.pdf&usg=AOvVaw0e6G55IzMoLKpjWmH-D9Zo

[RudydG 62]

Really? So there are 2 different sides on the original glass? This is extremely important information!

Never knew this.  Some glasses, (i have about 5 on the UM3 and 2 on the UM5) are turned over because of chips. And the i remove the little sticker to be able to use it flat. After that i swapped the directions probably several times. Introducing a extr variable.

Sander, we should have known this much sooner!

[Shadowman 53]

50 minutes ago, RudydG said:

Really? So there are 2 different sides on the original glass? This is extremely important information!

Never knew this.  Some glasses, (i have about 5 on the UM3 and 2 on the UM5) are turned over because of chips. And the i remove the little sticker to be able to use it flat. After that i swapped the directions probably several times. Introducing a extr variable.

Sander, we should have known this much sooner!

I am with you RudydG

 

As much as I appreciate the information; this should have be part of the original information as provided with the printer as well as with the replacement glass build plates.

 

I have always been told by both the  Ultimaker Support team and the distributors that both sides of the glass build plate are the same hence the ability to turn them over when chipped.

 

In my opinion; this is another great example of value of the aluminum build plate.

 

Takes care 

[Smithy 1,146]

1 hour ago, RudydG said:

So there are 2 different sides on the original glass?

I think it's only gonna make a difference if you print right on the glass. With glue or spray, it won't make any difference.

[Shadowman 53]

17 hours ago, Smithy said:

I think it's only gonna make a difference if you print right on the glass. With glue or spray, it won't make any difference.

Hi Smithy

 

Your thoughts do not negate mine nor those of many others.

 

I have had random adhesion issues and after understanding that the glass build plate has completely different properties on each side I am certain that I “now” understand why.

 

Takes care 

[Smithy 1,146]

5 hours ago, Shadowman said:

Your thoughts do not negate mine nor those of many others.

 

That wasn't my intention either. And that it doesn't matter with glue is just a guess from me, I didn't test it.

[Brulti 177]

The sides of the glass plates are different? 😮 Never really saw much difference... I print on the 'back', relative to the sticker, of one of my glass plate due to the way it is slightly bent, and it sticks as well as the other side when the printer is properly calibrated, ie first layer is squished enough.

[zungara 10]

 

Quote

On the tin side, the water will form a droplet (this side is hydrophobic). If you want to use an adhesion sheet, it is recommended to stick it to this side. 

 

I understand the difference between the sides if you want to print directly on glass. But why is it recomended to use the Tin side with adhesion sheet? What is the benefit to use Tin side with adhesion sheet? What will be the problems, if you will use the None-Tin side with adhesions sheet?

[geert_2 558]

@SandervG: This is weird, because I had the exact opposite experience when printing on bare glass, before I started using the "salt method. When the water spread out into a very thin layer, bonding of PLA would be bad: filament would curl up, the corners would lift, or the whole model would even come off. And vice-versa: when the water would stay in nice round bubbles, bonding would be reasonable.

 

Now, with the salt method, the water also stays in nice round drops. And bonding of PLA is very good, as long as the glass is warm.

 

So my reasoning was that the substrate (=surface to print on, thus the glass) should have a very high surface tension, and the wetting agent (=here the molten filament) should have a low surface tension. So that the molten filament easily attaches to the glass and spreads onto it. This is the concept what glues are based on, if I understood it well? (Correct me if I see this wrong.)

 

Anyway, salt increases surface tension and increases bonding of PLA. And soap and oils reduce surface tension and reduce bonding.

 

But I am no chemist, so I would like to hear the viewpoint of a chemist experienced in glues and bonding, for a better understanding of the basic laws of nature on this.

 

[SandervG 1,521]

On 2/4/2019 at 10:08 AM, zungara said:

 

 

I understand the difference between the sides if you want to print directly on glass. But why is it recomended to use the Tin side with adhesion sheet? What is the benefit to use Tin side with adhesion sheet? What will be the problems, if you will use the None-Tin side with adhesions sheet?

 

There won't be any problem if you use an adhesion sheet on the other side. But since the non-tin side provides decent adhesion by itself, perhaps you don't want to hide it underneath an adhesion sheet 🙂

[SandervG 1,521]

@geert_2, interesting that you have those experiences. Do you think the additives (like salt) make the water behave differently? 

[geert_2 558]

1 hour ago, SandervG said:

@geert_2, interesting that you have those experiences. Do you think the additives (like salt) make the water behave differently? 

 

Yes: they change surface tension: soap decreases surface tension (so the water spreads into a very thin layer), and salt increases surface tension (the water tends to pearl). That is how I came to the salt: I reasoned: if soap and oils reduce surface tension *and* bonding, then maybe I need something that increases surface tension, and hopefully bonding too? After googling, I found salt is one of the few things that increases surface tension. And it seems to work, at least for PLA, compared to printing on bare glass. But I am not sure this is the real cause, there could still be another explanation.

 

Also, in manuals on glue, you find that the *glue* should have a very low surface tension to make it spreak easily, so it can easily wet and penetrate the parts to glue. And thus the part to glue needs to have a higher surface tension than the glue.

 

I don't really know the chemics/physics behind it, apart from this simplification. If we would know more about the real mechanism, maybe we could find even better methods. And maybe this principle could also be helpfull for filament-development, to make it stick better to glass.

 

[superdave42 13]

Fantastic !!   I had no idea,   Thank you

 

[rien1959 1]

SandervG wrote :

"The difference is first introduced during production. When our glass plates are being made, near the end of the production line there is a hardening process. During the hardening process, the plates float on a layer of tin and are heated from above. This creates a difference between the two sides "

 

Now I understand why the glass plates are not perfectly flat. I 'm using 3 Ultimaker 2+ and 2 Ultimaker 3 printers. When printing objects larger than 80 x 80 mm I have noticed many times that the first layer is not equal. On some places it's transparent and on other places not. I'm a mechanical engineer and have had the buildplates on a grinded granite surface plate. It was very clear that all buildplates (10 pieces !) had a distortion in the flatness. Moving a dial indicator showed the high and low points very clear. I think this is something to think about.

[Abrasive 4]

I just did this test and my hydrophylic side was on the opposite side of the sticker.  It was definitely obvious as one side the water stayed contained and the other side it kept spreading slowly.

 

So I guess I have been using the wrong side of the glass but it has been working well for me with no extra adhesives? Or is the information in the original post reversed?

Edited March 23, 2019 by Abrasive

[Brulti 177]

I've been using the other side, not where the sticker is, nearly since I got the printer and plate because of the way the glass plate is slightly bent. Using the other side helps make sure the material sticks better by using the bend of the plate. I haven't really seen any difference between both sides of the plate when I put water on it...

[SandervG 1,521]

Hi, the information in the post is not reversed. It is possible that 'old' glass plates show smaller differences because we have optimized the manufacturing process some months ago which provided us with flatter glass plates but also bigger differences between the two sides. So it is possible that you have been using the other side and not run into any problems. If your adhesion has been fine, I would recommend to just stick to your existing workflow. For new glass plates, I would recommend to make sure you are using the correct side. Hope this helps!

[kfsone 5]

OH. MY. GOD.

 

I want to cry 😞 I was literally in the process of putting my UM 3 back in the box earlier this week after feeling so utterly betrayed when the printer started behaving like any-old $140 printer. But the real issue was I'd gotten *so* delighted with it, that to speed up my printing cycle, I had flipped the glass over to start a print on the other side. The first print had gone fine, and I forgot. But after that the printer went to absolute crap. The next print failed to adhere Colorfabb nGen, but not on the first few layers like you'd like. The result was a huge nasty blob of ngen which utterly covered both printcores(*).

 

I couldn't get Printcore 1 off so I followed a guide to strip down the print head. I got most of the ngen off both heads, I survived re-assembly of the printhead with only stupid derps (I put all the power connectors back in r-to-l instead of l-to-r).

 

But then I couldn't get any adhesion. I couldn't print the x/y calibration because either the head was too close and nothing came out, or the calibration just wouldn't stick and wound up wrapped around the print core (causing those little white pad things on the bottom of the print head to get sucked into a ball of filament while I was waiting for it to calibrate). I spent literal days messing with settings.

 

When I did find settings that worked on the first layer, things went back to crap the instant I tried a real print - I think cura tries to wipe the nozzle on the prime blob, which used to work with the same temp/ultimaker filament but now routinely just drags the blob into the print; brim and raft are welded so tightly to the model I have to try and design them into the print because they're not coming off...

 

The only thing I didn't think to try was to flip the god damn bed over.

 

Fortunately, buildtak seems to have come to my rescue. But ... this is something you need to get to your users!

 

Is there a way to permanently stain the bed? My sticker came off as I was inserting it into the printer the first time and then permanently the first time I cleaned the bed.

(* They *touch wood* seem to be working now ... but there's definitely some evidence of deterioration :()

Edited April 21, 2019 by kfsone

[LonRobinson3 0]

On 2/13/2019 at 10:38 AM, SandervG said:

 

There won't be any problem if you use an adhesion sheet on the other side. But since the non-tin side provides decent adhesion by itself, perhaps you don't want to hide it underneath an adhesion sheet 🙂

Is there a specific adhesion sheet that works well on the Ultimaker S5? Does this interfere at all with the bed leveling process?

[Enigma_M4 121]

On 2/13/2019 at 5:38 PM, SandervG said:

There won't be any problem if you use an adhesion sheet on the other side. But since the non-tin side provides decent adhesion by itself, perhaps you don't want to hide it underneath an adhesion sheet 🙂

 

Hi @SandervG,

did I understand right, that it would be possible to put an adhesion sheet on the tin side and then just decide printing on the glass-side (and adhesion sheet on the heat bed) and vice versa ("dual-use")?

Regards

[gr5 2,235]

Yes but you are going to tear your adhesion sheet very often anyway so it's not as wonderful as you might think.  Also you can print on both sides of the glass if you want.  If you use PVA glue I'm not sure that it makes a difference which side you print on.  I've printed on both sides of the glass on 4 of my 7 UM printers (so far) because after a year or so I usually manage to chip the glass.  It might make a difference but I haven't noticed.

[Enigma_M4 121]

So far, I used two plates: one to print on bare glass and the other covered with an adhesion sheet (both "sticker"-side), using the sheets mainly to print ABS and sometimes Nylon, the glass plate to print with CPE, PLA, TPU and Nylon.

Now this doubles the usability (two times bare glass and two times adhesion sheets using only two glass plates).

 

 

[mayo77 5]

Does this pertain to all ultimakers ? including ultimaker original, ultimaker 2 and ultimaker 2+ or just the newest ultimakers.