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Topic: Glass Thickness to print on

when changing out glass between prints what glass thickness is best to print on.
Should I use tempered glass.

Ultimaker S3.

2 (edited by Irish 2013-02-08 01:38:12)

Re: Glass Thickness to print on

I have a piece of 1/4" thick glass. Not sure if it's tempered or not but at bed temperatures of 100C degrees is not excessive for standard glass. Even the hot tip at 195C isn't an issue as it doesn't (shouldn't) touch the glass and the ABS cools fairly quickly. Once there is a few layers it's really only the bed temp. to be concerned about. If you are using PLA then there's even less of a concern.

I run at 95C bed and 196C filament with no issues at all.

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Re: Glass Thickness to print on

I use $2 glass from lowes, I think it's 1/8" thick. Works great.

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Re: Glass Thickness to print on

I found 2mm was too thin and flexed, and 5mm was too thick and didn't heat evenly.

Currently happy with 3/4mm.

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Re: Glass Thickness to print on

I'm currently printing on (very cheap) 3mm mirror+kapton tape... I had issues with thin layers of glass remaining attached to the print, hence the tape.

To do things properly, you should use borosilicate glass, and this is what I'll do next. It can be cut at home and it's very resistant to heat shocks. I haven't heard of tempered glass being used as printing bed, I guess mostly because it's difficult to manufacture and cut.

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Re: Glass Thickness to print on

Rincewind wrote:

I'm currently printing on (very cheap) 3mm mirror+kapton tape... I had issues with thin layers of glass remaining attached to the print, hence the tape.

To do things properly, you should use borosilicate glass, and this is what I'll do next. It can be cut at home and it's very resistant to heat shocks. I haven't heard of tempered glass being used as printing bed, I guess mostly because it's difficult to manufacture and cut.

I second the borosilicate

Former Solidoodle employee, no longer associated with the company.

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Re: Glass Thickness to print on

ERrr....you had pieces of glass stuck to your part? That seems really remarkable for glass to flake like that. Are you removing your parts very aggressively?


I use $2 2mm glass. Haven't noticed flex, but if I upgrade my bed I'll move to 3mm just to be sure.

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Re: Glass Thickness to print on

Tomek wrote:

ERrr....you had pieces of glass stuck to your part? That seems really remarkable for glass to flake like that. Are you removing your parts very aggressively?

No, not at all, it usually just happens during cooling down so it's pure thermal shock. The glass kind of delaminates. It's not dangerous but then the piece of glass is useless to print on. But it was cheap (IKEA) mirror glass, I'm not surprised of this effect.

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Re: Glass Thickness to print on

3/32" thickness here
rince please update us if you do play w/ borosilicate, i'd like to learn more

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Re: Glass Thickness to print on

You don't need to cut the borosilicate glass yourself unless you want a size that isn't offered.  I received 2 sheets of 6 x 6 inch Heat Resistant borosilicate glass at 1/8" thickness (~3mm) a few days ago from McMaster-Carr.

The part number is 8476K161 and it cost me something like $13 for each.

I have not had a chance to print with it yet, but I will soon.

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Re: Glass Thickness to print on

I imagine that cutting could be done with an ordinary diamond tile cutting wheel, I've completely replaced the Aluminium bed with a 1/4" sheet of glass, and drilled that happily with ordinary tile drills.

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Re: Glass Thickness to print on

danny wrote:

I imagine that cutting could be done with an ordinary diamond tile cutting wheel, I've completely replaced the Aluminium bed with a 1/4" sheet of glass, and drilled that happily with ordinary tile drills.

I'm not sure thats a good idea. Without the Aluminum, there is no heat spreader for the heated bed resistor.

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Re: Glass Thickness to print on

He also replaced the resistor with nichrome spread under the surface of the glass-

http://www.soliforum.com/post/6825/#p6825

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Re: Glass Thickness to print on

What's the point of using glass at all? Doesn't the stock bed work well for you?

15 (edited by cckens 2013-02-11 17:05:51)

Re: Glass Thickness to print on

Danny's solution allows him to heat the bed evenly whereas the aluminum bed heats center-out.

It's far easier to have a removable media, that you can swap out and continue printing almost immediately.  With the stock bed you have to either pry the prints off or wait til it cools enough to easily remove it.  Plus, you risk tearing the kapton on the bed when prying the prints loose.  With the removable glass, you have the ability to do multiple prints in short order. 

I like Danny's solution, but I'd have to have something with a connection for the glass so that I could swap out panes.  Other than that, it's elegant and works well.

Danny, how fast does the bed cool to remove the prints?

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Re: Glass Thickness to print on

The main reason that I swapped out the bed to glass was that I wanted a flat bed, my original bed started flat but seemed to warp over time, or perhaps I didn't notice at first and only noticed when I started trying to print bigger stuff.

The heating and cooling time is roughly the same as the aluminium bed. Cooling is about the same too.

I'm considering rewiring the heater if the bed to up the wattage so it heats faster but then I'll need to have a bigger power supply.
Not a problem as such (I have a bunch of spare server psu units that can deliver many more amps than is needed) it's finding the time that's the problem really.

I'm happy enough with the cool down time I rarely print things back to back so generally start a print when I get in from work and then turn the machine off a few hours later and go to bed, hence I don't care how long it takes to cool. But if I really really want a part in a hurry it's only ten minutes or so until the part can come off.

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Re: Glass Thickness to print on

Heh, I'm impatient, but it doesn't help that most of my prints are larger than the bed, so I have to break them down to components that fit the bed.  Thus I want to be able to rough assemble the parts quickly so I have less time between prints.