This Mysterious Rubber Block Can Count

Long before digital computers came along in the mid-20th century, we had mechanical counting and adding machines. Those varied in complexity and capability, but they could all at least count up by a single integer at a time. Most of those needed sophisticated systems of gears and linkages to perform their functions, but it turns out that humanity was over-engineering counting machines all along. All you really need to count up is some squishy material and a lot of ingenuity. Don't believe us? Then check out the Beam Counter designed by LKwak.

The subtitle for this project is "a Rubber Block That Counts!" That might read like hyperbole, but it is entirely accurate. This is, in fact, a big chunk of rubber that can count up every time the user pushes on it. And it can do so without any electronic components or conventional mechanical gear work.

So how does it work? The secret is in a clever series of slots molded into the rubber block. Those slots have a very specific pattern, with one thin column followed by one thick column, which repeats. When the user squeezes the block, those columns deform and fold in one direction or the other. They all start with the fold in one direction. But each time the user squeezes the block, one column forces its neighbor to fold in the other direction. When they squeeze the block again, the next column in the line flips its fold direction. This results in a tally of the number of squeezes.

Each column can represent a 1, but they can also represent larger values for unlimited counting potential. It is also possible to increment by multiples at once by squeezing the block more. That depends on the geometry of the block and its columns.

To make your own Beam Counter, all you need is a 3D printer and some two-component silicone with the proper supplies for mixing and molding. You'll use the 3D printer to fabricate the mold, which needs to have the proper geometry for this whole concept to work. You can also 3D-print a frame for the block, which makes it easier to perform a uniform squeeze and to keep it from resetting before you're done counting.

But if you aren't experienced with pouring silicone molds, you should know that it can be tricky. Air bubbles are a big concern, so it is very helpful to utilize a vacuum chamber or something like vibration to release those bubbles before the silicone cures. It might be possible to 3D-print the block instead of molding it, but most flexible materials aren't squishy enough for this purpose.