
Casting Glass from 3D Printed Molds - dezork
http://amosdudley.com/weblog/Casting-Glass-from-3D-Printed-Molds
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waiseristy
Also see 3d printed aluminum casting molds:

[https://www.youtube.com/watch?v=HVgPM1ojyLw](https://www.youtube.com/watch?v=HVgPM1ojyLw)

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donquichotte
Myfordboy is an excellent mechanic and engineer, and one of my favourite
youtube channels.

VOG [1] runs another channel that does a lot of (artistic) metal casting with
mostly 3D printed positives, called "lost PLA casting".

He uses casting plaster and built his own vacuum chamber and furnace to
improve the quality of his casts.

[1]
[https://www.youtube.com/channel/UCkEYj8wtK3aEW8vSGhlB43g](https://www.youtube.com/channel/UCkEYj8wtK3aEW8vSGhlB43g)

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msds
I taught a similar course at Pilchuck in 2015, which was the first
3D-printing/digital fabrication course taught there, and was also up there
taking a flameworking course when Amos was TA'ing for Yoav and Angela.

First off, Pilchuck is amazing, and if you're at all interested in glass, you
should seriously consider taking a course there.

Second, modulo a few tricks for clean burnouts, if you can print it, you can
investment-cast it in whatever material you want. It's amazing how powerful
cheap printers become when you combine them with a little casting skill - you
can access nearly arbitrary geometry in some useful, high-performance
materials without a $100k printer.

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greeneggs
Do you know what kinds of results are possible with a standard consumer 3D
printer? (A PLA printer?) The page says, "Any layer lines in the print end up
transferring through to the glass, which makes polishing a lot more
difficult," but does "a lot more difficult" mean impossible?

(I have an Ender 3 printer, and a microwave, so it looks like I can possibly
get started for <$100. But both because of price and turnaround time, I am not
very interested in using online resin printing services.)

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samplatt
I've got no practical experience with 3D printing, but surely dremel +
grinding/sanding bits = no more layer lines?

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wlesieutre
Yep, sanding is an option. I've also seen people fill the valleys with some
sort of goop filler and then start sanding from there, just to get it a little
closer to smooth. But I can't say if introducing different materials like that
might interfere with casting. They were doing it to paint over.

Another approach is vapor smoothing - you can use acetone vapor to smooth ABS
prints. Acetone won't do anything to PLA though.

I've heard of other chemicals being available for smoothing PLA, but they're
nastier than acetone and I don't know anyone who's actually tried them.

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namibj
You should be able to use acetone. See the solubility table [0] for PLA. It
takes longer, but it works.

[0]:
[https://onlinelibrary.wiley.com/doi/pdf/10.1002/app.38833](https://onlinelibrary.wiley.com/doi/pdf/10.1002/app.38833)

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dezork
Acetone really don't work well for PLA. You need tetrahydrofuran to smooth PLA
in the same way that acetone smooths ABS.

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swiley
Glass is definitely my favorite material to work with. I started messing with
it after following the instructions for setting up a lab in “The Golden Book
of Chemistry Experements.” (I can’t believe that’s a children’s book haha)

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bariumbitmap
> Once you have a model, the problem you need to solve is how to make a model
> with no undercuts. Undercuts will make it impossible to remove the 3D
> printed positive

Is there a mathematical term for solids with this property? It reminds me of
the vertical line test, but in 3D.

[https://en.wikipedia.org/wiki/Vertical_line_test](https://en.wikipedia.org/wiki/Vertical_line_test)

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b_tterc_p
Convex perhaps?

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FreeFull
There are non-convex shapes that don't have undercuts. I think convexity
implies that you don't have undercuts, though.

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itsEtai
This is great stuff!! As a hobbyist glassblowing and 3d-printer, this is
exactly the kind of content I’ve been looking for. Thanks!

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itsEtai
I did some pate de verre lost wax casting to make glass armguards a while back
but they turned out too rough to wear. 3d printing might be the answer! (Check
out my attempt here:
[https://www.instagram.com/p/Bk45IFqBhbL/?igshid=16fgxi4oubho...](https://www.instagram.com/p/Bk45IFqBhbL/?igshid=16fgxi4oubhod))

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samplatt
I'm curious about the too-rough-to-wear bit. Would an extra (leather/plastic)
layer below the glass be impossible?

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dezork
Pâte de verre is typically rougher than kilncasting from a larger billet,
because you're fusing glass granules without fully melting them together. So
you could get a smoother surface just by adjusting the peak kiln temperature.

But yea, certainly you could add a leather wrap underneath.

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alittletoolate
Here is another artist who uses the technique.

[https://mtyka.github.io/art/2016/12/11/lostpla-casting-
glass...](https://mtyka.github.io/art/2016/12/11/lostpla-casting-glass.html)

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oceanghost
This is fantastic. I've been wanting to make some custom liquor bottles. One
step closer :)

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drewroberts
This would be fun to get with our company logo in the last photo of the snake
head. If only we weren't paperless and could use a paper weight...

