The magazine doesn’t show all of the construction details, but if you want to be accused of Russian meddling in the science fair, here’s the project for you. For the young Soviet comrade wishing to take home the blue ribbon in the oblast science fair, the November 1970 issue of Юный техник (Young Technician) magazine gave enough information to build a fax machine. Apparently, it was called a “phototelegraph-integrator”, since that is the title shown here.

Both of the drums are spinning at exactly the same speed.  A scanner is moving across one of them, and a printing element, such as a pen, is moving across the other one, at exactly the same speed.  One of the machines scans a picture of the word Mir (peace), and this is transmitted to the printer, which makes an exact facsimile.

The bright American student can also build a device that can transmit pictures through a wire. The key is to have two drums that are spinning at exactly the same speed. The easy way to accomplish this, for demonstration purposes, is to simply have both of them revolving together on the same shaft. Both of them need to have something that moves along the drum at exactly the same speed. The easy way to do this, for demonstration purposes, is to have the sending and receiving elements connected together with a shaft.

One of those elements needs to have a method to detect the picture. In a fax machine, that’s done with light. But an easy way to do it, for demonstration purposes, is to create the image using aluminum foil. Then, the sensor can be nothing more than a piece of wire that comes into contact with the foil.

This wire is hooked to a circuit which operates a solenoid. The solenoid raises and lowers a pen which comes into contact with the other drum. Whenever the wire on the sending drum comes into contact with the foil, the circuit is closed, and the pen starts drawing on the other drum.

Turn the drum while slowly moving the two sensors. The result will be a drawing exactly the same shape as the piece of foil.

The crude drawing below shows the general idea. An advanced student should be able to work out the invariable bugs and build their own fax machine. When you take home the blue ribbon, the other students will probably accuse you of winning due to Russian meddling. When they do, point out that there was nothing in the rules prohibiting it.