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Friday Finds: 3D Printed Designs From the Shapeways Community


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Thanks for featuring the anti-dodecahdron. That's a shape I did in paper at least ten years ago, but having it in solid plastic is a great satisfaction.
I like a lot the other models showed here and I am more particularly impressed by the knotted cog: it makes me realized that a moebius-like strip cut into two give a trifoil knot...
#1 Magic (Homepage) on 2011-04-23 07:51 (Reply)
Ana, appreciate the mention on my paper-thin implicit surface, especially in the company of the other cool items this week. I've posted some photos of the actual printed piece in the "It Arrived" forum under the heading "Paper-Thin!." (The above image is a rendering from the model page.)
#2 vertigopolka (Homepage) on 2011-04-23 13:25 (Reply)
Hi Magic, glad you like the cog! A Mobius strip with 3 half twists gives a trefoil when cut down the middle. One half twist doesn't give a knot, 5 half twists gives a different knot.

Is it possible to cut the anti-dodecahedra into 6 pieces and stick them onto the dodecahedra in the tiling to give a single space-filling shape?
#3 Henry Segerman (Homepage) on 2011-04-23 13:31 (Reply)
This relationship between Moebius strips and knots is very interesting indeed.

Your question is interesting too... I don't think we can cut the anti-dodecahedron into 6 easily (it can be cut into 2 or into 4 in obvious way instead) which doesn't mean it is impossible.
If you just stick the anti-dodecahedron to the dodecahedron (see my video in the product page), you actually get a space-filling polyhedron (a 3D-equivalent of the fish shape you get by adding an octagon to an anti-octagon).
The problem is that this polyhedron is not convex. Now, can we transform this non-convex polyhedron into a convex one by cuting some parts and moving them elsewhere, I really don't know (yet :-)).
#4 Magic (Homepage) on 2011-04-23 14:55 (Reply)
Hey guys, my pleasure featuring these. :-)

@vertigopolka, thanks for the pointer, I just switched the photo

@henry congrats on the boingboing attention! Glad to see rounding up Friday Finds can result in good publicity for everyone here.
#5 Ana Hevesi on 2011-04-25 22:26 (Reply)
@Ana: Thank you!

@vertigopolka: with the photo it looks like it is a very tactile experience in person. Are the folds big enough to put fingers inside of?

It's a shame that it is so hard to describe how it feels to play with a model in person, particularly since I view it as one of the big advantages to having a 3d print rather than viewing it on screen. I now try to make sure that the scale of my models is large enough to allow for fingers!
#6 Henry Segerman (Homepage) on 2011-04-25 23:44 (Reply)
@henry: Yes, it's a very tactile experience. This print is a little over 3 inches on each side, only large enough to get my little finger inside the larger folds. I am going to try to make a larger print, and will keep the wall thickness down to the minimum; am curious to see how it looks (and feels) at a larger size.
#7 vertigopolka (Homepage) on 2011-04-26 00:09 (Reply)

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