3D printing arbitrary shapes without sprues, by embedding them in 3D-printed clear plastic

Originally published at: https://boingboing.net/2018/06/08/voxel-by-voxel.html


the links seem to be broken


Love the MIT Media Lab. I have a friend who went there and visiting his studio was always inspirational.


Sprues are not support bars; they are openings through which a casting material is introduced to a mold. In metal casting, where the molten material is poured from the top (as opposed to injected at high pressure from wherever is convenient, as in plastic injection molding), sprues are usually connected to runners which feed the mold from the bottom, thereby permitting air in the cavity to vent as the form is filled. When the casting has cooled, or hardened, or whatever, the sprues, runners and vents are cut away and the surface of the casting is chased.

tl;dr : Sprues are similar in form, but not the same in function as 3D printed supports.



More like a Vietnamese jelly cake, if the image is anything to go by.


The correct link: https://www.fastcodesign.com/90174994/the-gorgeous-future-of-3d-printing

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You meant ‘sprues’, I’m sure.


Thanks for the clarification on Sprues. I’ve been involved with 3d printing for a while and I had never heard that term before. Seeing it in this article made it sound like someone was just making stuff up–which is pretty common in 3d printing, but still.


My art school learnin’ is seldom relevant here (or anywhere else, really), so when those infrequent topics turn up, I like to jump on them and beat them soundly.


Now print these shapes in a soluble gel, and after the print is complete, wash away the gel.

I declare this idea to be in the public domain. Also send donuts


Yeah, this. Admittedly I only skimmed most of the article once I realised it was ‘like a fly in amber’. I guess it may be innovative in itself for 3D printing, but this kind of effect has been done in glass for a while - see many decorative paperweights. I get that this may be able to do things not possible in glass, but I was totally expecting it to be about getting arbitrary 3D shapes by doing something like your excellent suggestion.

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That is a cool idea, but I got the impression that the sturctures they’re printing permanently need the scaffolding, their positioning would fall apart if they didn’t have the casing.

Cory mentioned that technique in the post. It predates freestanding 3D printing by quite a bit; the architecture lab where I worked as a student in 1999 had a printer that worked that way.

(Actually I think the particular machine in my lab printed in glue on a bed of fine powder; after each pass, the bed lowered just a bit and the machine swept another layer of powder over it. You brushed off the loose powder when it was done. But I’ve also heard of solvent-based ones, and wax-based models where you melt away the wax in a little oven.)

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