Since I was a child, I’ve always loved mechanical devices of all shapes and sizes. I remember my grandmother’s cottage had one of those old totalizer “calculators” that you’d use a pen to slide the digits up and down and thinking it was the coolest thing ever. As I grew up I remember when I first read about the Curta calculator – it absolutely blew me away. Even then (back in the early 00s) they were already difficult to get and expensive, so I figured I’d never own one. Well, some incredibly dedicated hacker from Germany has created a 3:1 3D printed replica of the Curta that is fully functional!
At first, I was doubting whether 3D printed parts would hold up long-term, as the Curta is famously durable and very well-made. However, many of the important parts in this replica are made from CNC machined steel, like the main crankshaft. Other dimensionally critical components are printed in different types of plastic like PETG to get the best balance of durability, accuracy, smooth operation and price.
The Curta has a very unique place in history. We recommend reading Empire of the Sum by Keith Houston, which covers the history of pocket calculators from Blaise Pascal’s “Pascaline” devices, through the Friden STW-10, up through the Curta and on to the TI-81 and beyond. I was already a fan of the Curta but learning about how it fits in to the overall development history of calculating devices makes it even more interesting.
All in all, we at Tindie are simply blown away by the obvious passion and painstaking work that must have gone into creating this project. I can’t fathom how many prototypes and tweaks it must have taken to get things working smoothly while maintaining that lovely Curta look. With the holidays coming up, this should be on your list for any hacker you know that loves calculators and mechanical devices!
