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cor3ys

UM2 Glass Bed Melt/distorted

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Hi Guys

I have a really strange one, is it possible for the glass bed to melt to a print ?

I did a 35 hour print of the owl below as i was inspired by Ian's owl using colorfabb _XT-300. I had a bed temp of 60 degrees and was using a temp of 230 degrees for the XT Filament. I printed straight onto the glass.

When i removed the owl it looked like plastic was left behind on the glass plate but when i looked closer the glass was sunken not raised. when i looked at the bottom of the owl the marks on the glass were on the base of the owl but raised so it looks like the glass has transfred to the owl base.

How can this happen ?

Photo of finished print

Owl

Photo of glass bed

glass Bed

 

Photo of base of owl not very clear but you can just make out the material from the glass plate as the light shines off it.

 

Owl base 4

 

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I don't think it is possible for your glass to melt onto your print.

Other way around, yes.. that could be possible.

If you think your glass plate is damaged, can it be that your nozzle was too close to the glass?

Have you tried cleaning the glass plate? How does that effect the imprint?

 

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If I would have looked at this glass without knowing that something was printed on it I would have thought of hydrofluoric acid... But I guess, there is no fluorine in the _XT copolyester. Did you clean the glass before the print with any chemicals?

 

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Hi Guys

The marks on the glass are not raised it dips in, Yes i did try cleaning the glass as i thought the same as you it is not possible, but when i could not remove the marks i then took a closer look and realized the glass was actually marked/dipped in them areas...

Glass has been cleaned once before, Because when i first got it i used the glue stick but only used hot water to remove it. Since then i printed straight onto the glass and have done loads of prints with no issues until this weekend with the owl..

 

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good morning...

firstly... congradulations on the lovely Owl... really nice print :-) Happy to have inspired you :-) my one still sits beside my work computer :-)

About your damage..the only two ideas I have is that you printed your first layers too close to the glass that the nozzle scraped out the glass... mmmm ?

or some very strange chemical reaction between the chemistry in the colorfabb PLA material and the glass... that would be super strange.

Might be interesting to send the glass plate to ultimaker to let them have a look at it... ? But I havent heard or seen this problem from anyone else yet....

Ian :-)

 

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I have recently been having this happen.

I have had a good piece of glass from a stove bench top for a long time with no problems.

Recently I started using ABS glue (10:1 mix ABS to Acetone)

It was going good and prints had been sticking well.

One day I had this same problem when I pulled hard to get a print off.

Since then it has happened about 4 out of the last 5 prints.

I scraped off the ABS juice and put a fresh coat on to no avail.

The last print I did was easy to pull off the bed and some glass came off easily with it.

The glass isn't melted and is difficult to remove from the print.

It's like my glass has just packed it in.

Anyway I'm just going to use some normal glass for a while now while I decide what type of surface to use next.

 

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We have had small pieces of the UM2 glass plate transfer to a print, this was when using Colorfabb XT with 75C bed temp. We had to switch side on the plate.

In the beginning of UM2 printing I was a bit impatient so I used cooling spray for some prints to quickly chill the bed plate. My theory was that the quick temperature change perhaps made small cracks to cause this. But now that others are having this problem, I'm not so sure...

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Yes! :shock: :eek: :eek:

This is a real problem here! :evil:

 

Fortunately it happened before I had my UM2.

 

Well, in general, it takes from 70 ° C. He now faudrais whether it do the same with an unheated bed.

 

People are studying it?

 

Thank you.

Alex.

 

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Quick glance in our specifications only say that it is tempered glass.

I've never seen this happen in any of our test printers. (And we've done quite a few horrible things to these printers)

 

In any case, it would be actually good to give back plate Ultimaker for study. :ugeek:

In time, this might be a good idea. But right now, it's not a problem that directly causes major problems. If/when we ask for having it shipped back, we'll first ship a new plate so you're never without one.

I will put this on the agenda to look at.

 

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Hi all,

I've not had any problems because I don't have a glass plate on my printer BUT this sort of looked familiar....and I think the problem could be along these lines.....

From the Miele ceramic hob operating instructions.

''Do not allow either solid or liquid sugar or pieces of plastic or aluminium foil to get on to the ceramic hob when it is hot. If this is allowed to cool before the hob has been cleaned, the ceramic surface will be susceptible to pitting or even cracking.''

So if you allowed the glass plate (hob) to cool before removing the print (Sugar/plastic) then it binds to the glass and removal causes the pitting. The use of the glue stick could be acting like a barrier between the glass and the PLA/ABS so some people don't have the problem but as you printed direct onto glass it's stuck!

I have a large glass plate I use as a flat bed for making the models on. I get superglue on it at times and when I try to scrap it off with a scalpel sometimes a small bit of glass comes with it, more often then not it just scrapes off.

Anyway it's something to think about.

Regards

Mark

 

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Sorry to revive such an old thread, but...

I woke up this morning to a 25mm x 15mm chunk of glass missing from the middle of my platform, STUCK to the bottom of my print! :shock: What in the world do I do now?! Is this covered under the warranty? This happened before during the first month I owned my U2, but it was such a very teeny, tiny piece. Barely noticeable. More of a knick. This, however, is a definite missing chunk, maybe .2mm thick. I will not be able to print over this area anymore.

DETAILS:

 

  • Filament: White ABS from MatterHackers
  • Heated Enclosure:
    • Custom made acrylic covering entire U2 (like an upside down fish tank)
    • Custom made acrylic front door
    • I've measured the inside ambient temperature before with similar bed/hotend temps using my Fluke meter w/temp probe and it is a pretty constant 70c ~ 73c. It's nowhere near an air-tight seal, just trying to keep most of the heat inside and prevent wind gusts from air conditioner from ruining prints.

     

    [*]Bed temp: 105c

    [*]Hot end temp: 240c

    [*]Model dimensions: Roughly 76mm(W) x 48mm(L) x 2mm(H) Thin plate to mount a small speaker to.

    [*]Adhesion Method: Wiped thin layer of Elmer's glue all stick onto glass. Smoothed that out with water on a paper towel, then lightly swiped with dry paper towel. Couldn't see any glue, but it was still tacky to the touch. No acetone used (never have).

    [*]1st layer thickness: .08mm (same as all the other layers, trying to get chamfered bottom edge to print nicely)

     

    • I had this print fail just before due to clogged nozzle. So for this print, I sat and watched the first two layers go down completely before going to bed. Nozzle did not touch glass at any point. I had some thin areas here and there and adjusted the Z thumb screws a tad on the fly, but it never touched the glass. Filament laid out in nice, even, flat-ish lines with no gaps.

     

    [*]1st Layer Speed: 20mm

    [*]Speed: 25mm

    [*]Total Print Time: 4 hours

     

When I awoke, the print had completed a few hours prior and the part looked like it had warped up off of the glass. I didn't have to pry or work to get it off the plate. It picked up easily as it was already detached. Upon closer inspection, The part itself looks perfectly flat. It was sitting up off the glass a bit because part of the glass had separated and stuck to the bottom of the part, preventing it from laying flat. So just the normal cool down of plastic and glass caused the glass to snap away and stick to the plastic.

I have turned the glass upside down, started another print of some PLA (60c bed / 205 hotend / hairspray on glass) and left for work.

Do I have to buy a new piece of glass? If so, do I buy it from Ultimaker or can I find a place locally in Los Angeles that has this size and type of glass?

Help!! :???:

 

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I've not experienced this before and only read about it. The right course of action is to flip your glass and continue using the smooth side or getting a new piece of glass altogether. Sometimes, the print is etched into the micro fracture of the glass and then during cooling (when your piece "pops" off the glass), the bond strength between your piece and your glass became higher than the bond strength between different areas of your glass and the glass pops off instead. Seems like a rather unavoidable part about printing on glass. I wonder if anyone has any permanent solution.

 

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This is a common problem - the glue is stronger than the glass. I've only heard about this with PET. Not ABS. I really don't know what the solution is. It doesn't happen with PLA as far as I know.

Glass (fortunately) is extremely cheap in the USA because we have lots of windows in this country. So talk to a glass store and get 10 or so spares. Shouldn't cost much at all. I don't recommend the tempered glass as I'm not sure but that might be part of the problem. UM2 glass is normal tempered glass. But what do they know? Maybe regular glass is better.

 

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I contacted Simon @ fbrc8.com and he's sending me out a replacement pane of glass under warranty. This new "1 year retroactive" warranty comes in handy! :)

@Gr5: isn't this some kind of special glass? I mean, isn't it a special kind of glass to withstand the heated bed? Tempered? Made by Elves? If nothing else, it's thickness is specific so the clips will hold it in place. Would need it to not overhang as the overhung part might be a different temperature than the part that's contacting the heated bed. Might not be a concern, I don't know, just thinking out loud.

 

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In the last two days, I've had pieces come off my UM2 glass print bed, still attached to the bottom of my prints. The first one I didn't mind too much; just flipped the glass and was fine. Then some came off that side and now I have to wait till the new plates come in to do any more printing.

I'm pretty sure the whole thing was my fault. I had gotten used to taking the glass bed (with print attached) out as soon as it was done printing and putting it on top of my computer, where the computer fans would blow on it and cool it a bit quicker than just leaving it in there to cool with the rest of the printer. The wear and tear of this after dozens of prints probably caused weakness in the glass to build up. Then, when I printed something big enough to stick to enough surface area of the glass, the bond between the bits of glass and print was stronger than within the glass bed itself, as pointed out above.

Today I learned not to induce sudden thermal shock to the glass print bed. Eventually, it'll break down on you.

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Tempered glass can't stand sudden temp changes. But you could try to buy a high temp ceramic glass, used in fireplaces. That glasses can resist high temp and sudden changes. It's on my long to-do-&-buy list of thinks to try.

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Something like this?

https://www.onedayglass.com/types-of-tempered-glass/heat-resistant-glass/neoceram-glass/

Going through their online quote interface, it looks like a piece of 5/32 neoceram black glass (not transparent at that thickness, for some reason, but the closest thickness to what the UM2 comes with) runs about $60. Might be worth a look.

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I picked up a pair of tempered glass panes cut to the UM2 bed size today. After a relatively-quick 4 hour ABS print, the stuff is clear and ready for more. I'm anxious to see how long these last, if they break down at all. Grand total for both panes was about $60, the same price as a single pane of that ceramic glass above.

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