Thanks! I haven’t actually published these pieces yet. (Well, the slide-glide cyclide thing was published by someone else, but I think it was later taken down–there may be plans for the original mathematician to sell them?) The puzzle box is just a little too kluged together to really publish; I modified a lot of things after the fact to get it together, and I’m not comfortable publishing it in that state, but I also don’t really want to put in the work to finish it. The kaleidoscope would actually be okay, but it’s limited–it’s a bit tricky to actually cut the mirrors, and it really only works to reflect things right up against it. I want to design an adapter for it that will hold an acrylic sphere (which you can get inexpensively from China) so that you can use it to look at scenes as well. But I haven’t actually gotten around to that yet either. I’ll give some thought to publishing it as-is, though.

I dunno. I agree with this to some extent for sure–I don’t print a lot of the meme models that are everywhere on 3d printing forums. But there are toys that would not exist without 3d printing that I think are pretty great.

I designed a kaleidoscope that reflects things not to tile a plane, but instead to tile the surface of a disdyakis triacontahedron: https://imgur.com/gallery/i-made-kaleidoscope-P4atHey I had to cut the mirrors from acrylic by hand, but the templates for them and the shell that holds them in place are all 3d printed. And that thing is a pretty great toy.

This thing: https://imgur.com/gallery/make-of-cyclidial-iris-by-vergo-henry-segerman-XHN4MC0

is a math sculpture that I didn’t design, just printed, but it’s completely beautiful, and it’s had real staying power as both a toy and a decoration. It sits out on our coffee table all the time, but my niece plays with it every time she’s over here.

And this puzzle box I designed: https://imgur.com/gallery/i-made-puzzle-box-nieces-birthday-U1q408R

was a big hit with her too. I’m not sure if she’ll continue to play with it long-term, but based on my own tendencies as a kid, I think she might end up investigating the mechanisms involved for some time to come.

Things that you could buy at the store you’re generally better off buying at the store. But there are things it’s not economical to mass produce, and it never used to be possible to design and make your own toys. Both ideosyncratic toys and bespoke toys are pretty great uses of 3d printing in my opinion.

Not as far as I know. Practically speaking there are several disadvantages–the slots limit the light on the markings, parallax effects can mess with the reading, it requires two full surfaces sliding against each other which increases friction, etc. Plus with a regular vernier scale you can see both sides of a line, which could give you a better sense of how they line up (“vernier acuity”). But in a case like this, where precision isn’t a top priority and ease of use might outrank it, I think there’s an argument to be made for it.

I wouldn’t have caught that the gallery link was wrong if you hadn’t mentioned not knowing how the tool was used, so thank you as well!

Yeah, it’s definitely not the most precise thing. It’s good to around ±1mm. I tried to measure 1.75mm filament with it, and it just reads 1, not even between 1 and 2, so for critical measurements the physical matches are definitely better.

Edit: at some point I realized that I was thinking about this particular measurement wrong. 1.75mm filament has a radius of 0.875mm, so “1” is the closest reading this tool can produce. Whoops! Still, it’s definitely not better than ±0.5mm.

And yeah, here the vernier effect is not giving very high precision; it’s just giving a way to space the marks out enough to be printable, but indicate movements that are as small as a printed line.

Sorry, just realized I also had the wrong link for the gallery that included photos of the tool in use! I edited the post, but here’s the corrected version of that: https://imgur.com/gallery/moire-vernier-radius-gauge-design-3d-printing-ajy0GBg

Sorry all! I meant to post a video of the moire/vernier effect in action, which is the most eye-catching part of the whole project, as the main image for the post, but it didn’t upload. And now when I try to edit in a link, or post a link to it in the comments, it’s telling me “blocked URL.” But there’s a link on the printables page, and the version with the older version is in the imgur gallery which is linked.