The Curta Mechanical Calculator – Mechanical Hacking Inspiration

Curta mechanical calculatorIf you’ve read this site at all, you’ll know that I greatly enjoy designing and building mechanical as well as electrical devices.  Most aren’t that useful, but are interesting to me.  They allow me to flex my “engineering muscles” in ways that I enjoy even if they wouldn’t be practical or necessary at work.

Recently though, I found a device that was really incredible.  It’s called the Curta “pocket” calculator, and it works on purely mechanical power.  Appearing like a pepper-grinder, this device has largely been forgotten in the age of transistors.  Smaller and better calculators can be had at your local dollar stores, but there is something really amazing about how a tiny geared contraption can be capable or addition, subtraction, multiplication, and division.  You may not have heard of the Curta Mark 1 or Mark 2 (the latter which was capable of an astounding 15 output digits!), but I thought it was worthy of mention here even if I didn’t actually build it.  Check out the video after the “Read more” thing to see one in action with a better explanation of how it works!

I don’t personally own one, but if you have one you’d like to exchange for, say, some advertising, feel free to drop me a line.  If you can’t afford the $1000 or so required to own one of these, you can always just play with this “Curta Simulator”.  Ironic that something designed to work around the world’s lack of transistors can now be graphically simulated using these same devices.  One would wonder how large a space would be needed to make a “virtual Curta” using only gears and other mechanical elements.  I guess it would have to somehow flip pages to change colors on mechanical “pixels.”  I’d love to hear your answers in the comments – I’m putting my random guess down as 1000 cubic yards. 

As for random mechanical devices that are unique to, check out this MDF Geneva Drive, this bolt-action potato gun (both made by me), or this drill made out of a pencil sharpener (by Jason Underwood)!


  1. Hackaday Links May 9th 2012 - Hack a Day - pingback on May 9, 2012 at 8:02 am

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