Is glass necessary as a print platform?

[sunkenbier]

Im printing some prints with a very large base. They are often getting stuck to the glass plate and Im unable to get them off. In yesterdays attempt the glass plate finally broke. That got me thinking. Why is a glass plate necessary? Can something like galvanized metal or copper be used? Will that cause an issue with the heated bed?

I was also considering putting two of these back to back on the heated bed.
http://www.matterhackers.com/store/prin ... 2-diameter

This would allow the print platform to be removed after the print and since the material is flexible you can just bend it right off. Anyone see a flaw in this idea?

[mhackney]

There is no magic in glass except that it is very flat for low cost. I use PEI adhered to my glass so I am actually printing on PEI. I could have mounted the PEI directly to a sheet of aluminum but it is very difficult/expensive to get AL that would be as flat as the glass.

I am not aware of anyone having success printing directly on galavanted metal or copper and I can't image that you could get either of these as flat as the borosilicate glass without breaking the bank.

BuildTak is good stuff, you can read about my research with it in my build thread. You are not going to gain enough stiffness or flatness by putting them back to back on your bed. You really need some very flat, reasonably thermally conductive bed. Why not put a buildtak on a new sheet of glass? You will have 22 different surfaces to choose from.

What material were you printing that stuck to your glass bed like that and what did you have on the glass (gluestick or ??)?

[sunkenbier]

I was printing on a buildtak stuck to the glass. The print base was about 8.5 inches square and adhered to the builtak far to well.

[mhackney]

What material were you printing?

You most likely also have your Z height set incorrectly. Have you printed a single layer thick object and measured it?

[sunkenbier]

I have not. Are you thinking the first layer is to thin so it is sticking to well?

The material was ABS

[mhackney]

Yes, that is exactly what I'm thinking. BuildTak is good stuff but you have to get the Z=0 set properly or it will stick too well. The easiest thing to do is decrease you Max Z length by .05mm increments and print something small. Test to make sure it is sticking when you print. Once it fails, go back to the previous setting. Or you could read the post in my signature and set your Z height by measuring a single layer calibration part. Both work and once you have experience, you can just eyeball it and be right on.