Unanswered Has this happened to anyone else?

So my abs print finished, let it cool, hear the snap crackle pop and after a bit I went to have a look.
Part was still a bit stuck so I wiggle it a bit to get it loose. Look at the bottom of the print and theirs a piece of glass stuck to it.
I use the purple glue stick to help things stick and the corners still warped a bit, but stuck to well for that spot of glass.
Do they sell replacements or should I buy a piece of glass to put on top?

 

That doesn't look like a piece of glass. That looks like excess glue/adhesive.

 

I wish that was the case, but the spot in the 1st picture is about .25mm deep.

 

I've seen it happen before. It's pretty uncommon though.

If your printer is still under warranty you can submit a replacement part request. Otherwise they do sell a replacement.

http://www.robo3d.com/collections/r...cts/replacement-heated-borosilicate-glass-bed

 

It's 3 to 4 months old. Do you have to be the original owner for the warranty?

 

I don't know, doesn't hurt to submit a replacement part request

 

I'll try it then.
Don't really have the cash to buy a replacement ether.

 

This just happened to my build plate also. I printed a 20mm calibration cube, and when i pulled it off, there was a chunk of the glass missing. Its just a little one, but its right in the middle of the build plate where the parts are printed.

 

Does anyone know what causes the glass to break like this? I was only printing a PLA cube at the default settings. 210* extruder and 50* bed. I was pretty gentle in removing it after the bed cooled. Should I be removing it while still hot? I just want to know how to avoid this in the future. Or is it just a defect on this piece of glass? Does everyone else cover the bed with something else?

 

Was the glass cold or hot when you removed the part

 

The glass was cooled. This is my first printer and I just assumed that if heat makes it stick, then it would unstick better cold.

 

That's correct. I'm not sure what causes it. Microfractures in the glass primarily

 

I just submitted a replacement request. Hopefully they will send me one. When I get a new one, im definitely going to put another piece of glass or one on those printinz flexible plates or something on there. Will the auto leveling account for the thicker plate automatically, or will I have to adjust something. I have one of the R1s with auto leveling and 8mm rods and magnetic build plate. (Had to flash the proper firmware on it to get it to print the proper Z height)

 

The problem with letting your build plate cool to remove is that the plastic cools faster, which is why it pops off, but this is also what is breaking your glass plate. If you get a really good adhesion to the plate the pulling of the plastic while it contracts fractures the glass. Enough times and those micro fractures become a glass chip stuck to your part. This is why I remove my parts while the bed is hot. Better to mess up a warm soft part than an expensive glass plate.

 

frosted glass IS made by applying a glue and allowing it to shrink as it dries.

Neat process... did a term paper on organic adhesives for OChem.

 

I think this might be another one of those issues where an enclosure for the printer would go a long ways. It would allow everything to cool down a lot more slowly so there is less stress. Just like a cheesecake being allowed to cool in the oven or covered on the counter keeps the top from cracking.

 

At this point, the bed seems so fragile to me, that Im going to keep something on top of it that I can easily replace. Ive always been careful with the bed and it still broke after only a dozen prints or so. I never touched it with that scary metal scraper it came with, and only used aquanet on the couple of larger prints I made. I think now that the aquanet might be important as a protection layer so it can be detached, and not just to make the print stick. Im going to get a 15 x 9 piece of glass to clip on there now regardless of whether or not I get a replacement bed. I just have to figure out if the auto leveling will adjust to the new thicker plate, or if I will have to change some settings.

 

Here's a good sized replacement: http://www.ultibots.com/borosilicate-print-surface-250mm-x-320mm/

 

Pyrex might be a bit tougher.

http://www.mcmaster.com/#glass-stock/=wdmy2c