Glass thickness - does it matter much?

I've been using 2 mm thick window glass, but I have 3 and 4 mm available. Some window, mirror, and smoked. Have not bothered buying borosilicate yet, but I might at some point.

Any recommendations or comments? Does it have much of an impact on anything?

I also have 5 mm, but I'm guessing that is pretty thick, no need to use that stuff! I run things at a fairly low speed, quality over quantaty kind of thing. But there must be a limit.

What is everyone else using, thickness wise?

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Yvan

Singularity Machine

3mm plain glass

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_______________________________________
Waitaki 3D Printer

1.75mm dollar store picture frame glass.

I recently came across a posting from somebody who advocated using Kapton on aluminium instead of glass. His logic was that the thermal conductivity of glass being lower than the aluminium spreader plate, the highest temperature would be under the print - the further from the nearest print edge the higher, and that the lowest temperature would be on the parts of the bed without any print on it. The lower at the edge would tend to allow seperation and curling of the print. If correct, the thinner the glass the better.

It sounds good enough to me and I will be trying it as soon as I get a chance. I have found that anodised aluminium sheet is usually harder than the un anodised stuff and that 2mm anodised sheet is pretty much dead flat.

Mike.

p.s., of course, like anything else in 3D printing, it could all be hooey and your milage almost certainly will vary

Glass is actually a bit stronger than most of us think, provided you don't shock it, or put a lot of pressure on a small point. So for a standard size print bed, thin is just fine. For larger formats, the glass thickness will increase with your maximum direction. In my case, 28" long, my glass supplier recommends 3/16 9around 5mm) so at 300 x 300 you can probably do 3 mm. Just be sure to use something to cushion the points where your height adjusters are going, so that your height screws don't crack the glass. I'd suggest some of those adhesive cork dots (not felt) like you use under a lamp to protect a table. Rubber feet would also work.

mirror holds up much longer than plain glass, the mirror coating works to distribute heat much better than plain glass.

I have some 1.75 mm picture frame glass, will try that. I had been wondering if it was too thin!

Mike, I'm going to keep that in mind. Maybe I could slip a thin sheet of aluminium under different thicknesses of glass and see what happens. I've got a few off cuts of 1100, it's 99% pure and a good heat conductor. Any 1000 series alloy would be good conductors. 100% alum sheet is not as easy to find. Don't like the idea of dealing with Kapton much though...

Not sure if I understand where the heat is going though. If it is moving out of the glass and into the printed part above it, wouldn't it be cooler under the part than around it?

Maxx, what do you mean when you say "the glass thickness will increase with your maximum direction"

DS, I should try that too, I've got an assortment of mirror glass to try with.

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Yvan

Singularity Machine

Quote
Yvan
what do you mean when you say "the glass thickness will increase with your maximum direction"

He means that the size of the bed height x width determines the thickness of the glass you need to use.
If height <> width then the larger of the two determines the thickness of glass required.

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Bob Morrison
Wörth am Rhein, Germany
"Luke, use the source!"
BLOG - PHOTOS - Thingiverse

Right, proportional, so it maintains rigidity...

Thanks!

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Yvan

Singularity Machine

The heater guy I spoke with yesterday recommended aluminum for larger surfaces, They machine the plate and ship it with the heater attached. I'll have a quote on the heater (only) next week. I wonder how much THAT's going to be.

Maxx Mayhem Wrote:
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> The heater guy I spoke with yesterday recommended
> aluminum for larger surfaces, They machine the
> plate and ship it with the heater attached. I'll
> have a quote on the heater (only) next week. I
> wonder how much THAT's going to be.


That is very interesting. Please keep us posted!

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Yvan

Singularity Machine

Kapton on AL works just fine.

But now I wouldn't print on anything but mirror tiles. 2.25mm thick and I haven't replaced one in about 6 months, and that was me being stupid (too much ABS juice+too high heat=permanent adhesion).

Same glass on both machines. One 300mmx300mm, the other 250mmx250mm.

ABS only. Same procedure nophead outlines. A little juice then a wipe with an acetone rag. Zero warp at 95C.

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- akhlut

Just remember - Iterate, Iterate, Iterate!

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