Three-Sided Cylinder Coins

Three-Sided Cylinder Coins

Three-Sided Cylinder Coins 628 472 mathgrrl

Today we 3D printed some cylinder coins for students and classrooms to experiment with after watching Matt Parker’s video How thick is a three-sided coin:

These “fat coins” can land on their edges as well as their faces. Try out different thickness-to-diameter ratios and search for the fairest three-sided cylinder coin!

We made coins for five popular ratios with Tinkercad: the two ratios tried in the video, plus three inbetween:

We also made a parametrized version in OpenSCAD so you can try any ratio you like:

Screen Shot 2018-03-06 at 4.59.27 PM

If you don’t have access to a 3D printer, you can purchase 3D printed sets of coins from our Shapeways shop, in the same ratios as shown in the Tinkercad photo above, or as a set of 10 coins that range in ratio evenly between the 1:2*sqrt(2) and 1:sqrt(3) ratios shown in Matt Parker’s video. To save on per-part costs, the 3D printed coins print in a cage which you can break open after shipping:

Here’s what the 10 variable-ratio coins look like after removal from their cage:

Students, educators, and experimenters: if you want to get involved and add data to Matt Parker’s collection, check out Matt Parker’s follow-up video Help me find the thickness of a three-sided coin!..

Happy flipping!

 

——————

As an Amazon Associate we earn from qualifying purchases, so if you’ve got something you need to pick up anyway, going to Amazon through this link will help us keep Hacktastic running. Thanks! :)


Leave a Reply