I digitally reconstructed the rare SG 41 cipher machine as a fully interactive 3D preservation project

For the last decade I’ve been working on *Virtual Colossus*, a long‑running project to digitally preserve early computing and cryptographic machines by rebuilding them as interactive 3D simulations. My newest reconstruction is the SG‑41 — a late‑WWII cipher machine that most people have never seen in person because only a handful survive.

I wanted to create something that doesn’t just *look* like the SG‑41, but actually *behaves* like it:

* the internal mechanics are animated from historical documents
* the stepping logic and encryption process are implemented accurately
* you can rotate, zoom, and explore the machine from any angle
* everything runs in the browser so anyone can access it

Like the Colossus project, this is part of a broader effort to preserve machines that are too rare or fragile for most people to ever interact with physically.

If you’re into digital preservation, crypto history, mechanical engineering, or obscure WWII tech, you might enjoy exploring it:
[**https://sg41.virtualcolossus.co.uk**](https://sg41.virtualcolossus.co.uk)

Happy to talk about the research, the modelling process, or the historical sources behind the reconstruction.

[Virtual Schlüsselgerät 41](https://preview.redd.it/k18076180esg1.jpg?width=1920&format=pjpg&auto=webp&s=c7a7831ed8c44ed58790a2163aa1187a71034847)