Activity 95 - Coding machine
The Enigma machine was used in the second world war as a coding machine to keep messages secret. You can make a simple coding machine out of KNEX, as shown opposite.
The top section slides backwards and forwards, to allow you to change the code as often as you want.
There are more photos showing how to build this model in the Guide.
Q1. Can you use your coding machine to send secret messages to a friend?