Design for magical spherical dice (3D printed)

I designed a die. It’s special because it’s a sphere pretending to have six sides: each roll will end with one to six dots facing up. It’s also special because you can print a copy. The trick is a weight that falls into one of six pockets under each of the numbers. “Spherical dice” sounds better than “spherical die,” so print two.
Some assembly is required: You just have to drop in the weight and jam in the plug. According to the colleague that helped me, Nobuyuki Umetani, fishing stores are the best place to get lead. For the plug, you can use your thumb. Most of the plug will still be sticking out post-jam and you’ll have to snap off the rest. The way many printers print makes them snap clean along the path of the printer head. So score the plug by drawing a knife around it’s diameter where it meets the sphere, steady it (with a vice or on the edge of a table), and give it a good whack.


  • The roll has satisfying action. Video at bottom.
  • The plug is tapered so as to jam well. It functions as the number one.
  • With this design, the strength of the jam may influence the fairness of the die. Probably not a real concern (since the ball’s mid-air choice of pockets will have a bigger influence on the outcome), but this is an imperfection in the design. Someone will have to do a few thousand or so rolls to make sure.
  • The density of the fill and the weight of the missing dots could also influence a die’s fairness, but if you care that much then you know not to bet six with any dice that didn’t come through a casino.
  • You can fill the dots in if you want them to stand out. Nail polish will do. Just be careful: the plastic doesn’t forgive mistakes because its layers act like capillaries and suck up liquidy paint (or nail polish removered nail polish)
  • You want the diameter of the lead weight to leave some wiggle in the pockets. If your weight is a snug fit into the die, get a smaller weight (or scale up the size of the model).
  • I’ve oriented the model at an angle so that it’ll print correctly (without any support material on the inside) if your printer can handle printing a 45° overhang. It probably can? I don’t know how common that is, but the machine I used can.
  • The original design subtracted an octahedron from the center of the sphere, but it was a little too sensitive, and also harder to make fair, so I redesigned it to subtract three mutually orthogonal boxes.
  • Workflow was 123D (for the orthogonal part) to Meshmixer (to sculpt out the dots) to MakerWare (staging and path planning) to a second generation Replicator.
  • I got the idea from someone who did the same thing in wood. I saw it for sale at a store call Aha.

And, this is how I roll:


This entry was posted on Saturday, July 26th, 2014 and is filed under straight-geek, tricks.

Chrome extension: Facebook deconditioner

I used to find myself on Facebook even when I did not want to be there. Now that doesn’t happen any more. Every time I go I have to click through a bunch of popups. The number of popups increases by one each time I return. I can still check the site, it just takes a little work, and a little more work each time.
With the carefully engineered convenience of these sites, you can reach a point where spasms of muscle memory override your own intentions about where you want your mind. If you think a small simple barrier would help you be a more mindful consumer of social media, you can install an extension I made for Chrome.
Even if you check the “do not show popups” box every time, this plugin will still force at least three clicks before every page access. And it will still make it easier to stop than to continue. And it will still keep count.


Here is the early code (you can ask me for more recent code). And these pages are useful for authoring.


This entry was posted on Monday, May 19th, 2014 and is filed under straight-geek, tricks.

How to learn every spice in the cabinet

So many of my peers are going epicurean. Its beautiful because I think cooking is empowering: it encourages people to try new things and experiencing new ways of thinking. It worrisome because it provides another thoroughly commodified identity, with all kinds of vocabulary for justifying not liking something. I spent a year convinced that I knew how I liked my coffee (and that I didn’t like it any other way). I finally admitted to myself that it was a delusion, and that the variance between cups of coffee was greater than my ability to tell the difference.
So we’ll focus on the first: empowerment. I never knew how to use the spices. I figured that the best way was to just cook lots of recipes by the book until I got the hang of it. But so much of the joy of cooking, for me, is making stuff up. For a while I just cooked without spices at all. I still prefer it that way, but I wanted to learn the spices, so I shifted to throwing in tons of random everything. Occasionally I would make things that worked. While the random approach will eventually start to pay off fine, it requires a certain affection for failure.
Though my stance towards failure is particularly affectionate, I did eventually refine my technique, and now it is fancy enough for anyone to learn to use any spice. Did you know that taste and smell are thoroughly integrated senses? Did you know that the tastiness of coffee and chocolate is entirely illusory? Coffee and chocolate have no taste. They are entirely smell. Try eating chocolate while holding your nose: all you’ll taste is the added sugar. And you can use this confound of the senses to simulate the experience of a new spice without committing to it. Soup is the easiest for this technique, so I’ll focus on it, but it works for everything:
Make your soup without any spices at all, throwing in all kind of stuff and putting off any spicing towards the end. When you are ready, ladle a little thimbleful of soup into a cup and walk over to you spice cabinet. Now open a random spice, take a sip of the soup, and smell the spice, and the next spice, and on down the line. By mixing smell and taste, you can simulate the experience of the soup with the spice. If you like what you are tasting, add the spice to the soup, erring on the side of too little. You can try all kinds of exotic spices and figure out what you like with impunity. Its simple and intuitive, and it will eventually get you a familiarity with the spice cabinet that you didn’t imagine yourself capable of. Feel the power of spice through your main course!


This entry was posted on Friday, February 24th, 2012 and is filed under life and words, tricks.