Hi All,
i noticed that i had really huge problems with printing, did not mather how i leveled the bed there was always an issue with wonkey prints, so i decided to change to PIE when i noticed that there was a crack/chip on the one side of the bed where you fasten the bed. i might have done that when i screwed the bed to the build plate… dont know any how do i change the glass whith out damagig the heatbed part ?
any tips/ trix ?
br
Bre
Ditch that crappy glass. I’m shocked Lulzbot keeps putting that crazy thin glass on these printers. I broke 4 plates before I finally gave up. I went to my local glass shop and had them cut me a 11 3/4" x 11 3/4" tempered piece of 3/16 glass. It is WAY stronger. I had to order a new heater and glued it to the bottom of the new piece of glass. I also purchased a PEI sheet and glued that to the top. I have since made hundreds of prints on that set up with zero issues. They need to just make these machines with thicker glass. Most of the machines on the market that have thin glass DON’T have the glass attached to the heater. The heater is a metal plate and the glass just sits on that plate and they are also smaller build plates. With a 12x12 build plate you really need a much thicker piece of glass ESPECIALLY since the glass and heater are all one thing. You break it and your screwed. The tempered piece of 3/16" glass AND PEI sheet AND 3M adhesive was still significantly less then just the factory glass plate. There is just no reason to replace the broken plate with another thin piece. Save yourself some cash and upgrade at the same time.
thank you, for the advice!. 
gone see if there is a company that can do it for me here in sweden.
how did you get the M3 + PEI leveled, when i tryed it was bit uneven, due to there was 2 layers of boubles first the one to the buld plate that i tryed to puncture and massage out, but the boubles in between PEI and M3 was not possible for me 
Br
bre
I used a glue roller to flatten mine. It seemed to work pretty well.
I have used the 3mm borosilicate glass for almost 4 years now with thousands of prints (and 2 different printers) and the only one I ever broke was because I dropped it on concrete.
Borosilicate glass is very strong, tough and less prone to thermal shock than regular or tempered glass.
How large are your prints? I never broke the glass on little 2-6 hour prints but I have 24 hour plus prints that take up the majority of the platform and getting those off was a HUGE PITA. Those were the prints that constantly broke the glass.
I print huge things fairly regularly. Before I started using PEI I was using the stock bed and PET. Never had any problems with removing the parts with the magic cheese wedge of destiny. The people that seem to have an issue with destroying glass on a regular basis are the ones who print directly on the glass usually.
Magic cheese wedge of destiny? I have upgraded my scrapper/part remover to this:
http://www.homedepot.com/p/Husky-Allway-3-in-Bent-Extendable-Scraper-BS3HD/202251540
That little tool is awesome for removing parts.
Yup, This one specifically:
http://www.amazon.com/Calphalon-Gadgets-Dual-Cheese-Plane/dp/B000SDQGL6/ref=sr_1_100?ie=UTF8&qid=1420849759&sr=8-100&keywords=cheese+slicer
I tape over the slicer part with some heavy duty duct tape to keep it from digging into the bed. The two side pieces act as reinforcement for the really thin front wedge section. That pain scraper looks interesting too, i’ll have to give that one a shot too.
I just had a chip come off the glass bed. I wasn’t having good success with the PET tape that was on the bed orginally so I removed and hairspray or the ABS/Acetone solution has been working well… till now… Printed a bunch of corner brackets to build an enclosure for my taz, all but three were completely free sitting on the bed once it cooled. Gently tried knocking one of the three stuck and it pulled a small piece of glass up with it. Other till are still stuck on… need to figure out how to get them off.
If I were to replace the glass, is the heater removable and reusable on a new piece of glass? or do I need a new heater as well?.. That’s the more expensive part.
If you’re careful you can remove the heater by carefully peeling it off the glass, but you may want to look into using PEI instead of the bare glass, as it can lead to damage. More information on PEI: https://forum.lulzbot.com/t/pei-bed-surface/690/1