Crack the Cam Lock

A black and orange exhibit table, with a brown and white information panel at the back. On the table sits a steel and perspex combination safe with colourful cams visible.
A black and orange exhibit table, with a brown and white information panel at the back. On the table sits a steel and perspex combination safe with colourful cams visible.

Cams are used in certain kinds of locks.

How it works

Turn the dial to line up notches in three cams and open the safe door.

Things to try or ask around the exhibit

  • Can you crack the code and open the safe door?
  • What combination of numbers do you need?
  • What's special about the cam-shaped discs in the oversized lock?

Background

Usually, we see cams being used in motors, but they can also be used in combination locks. By lining up the notch in each cam against a number dial a security code is created within the combination lock. When the cams are randomly mixed in orientation, the lock's shaft cannot be released through notches in the cams.

Finding the science in your world

Combination locks are often found on safe deposit boxes, bike locks and suitcase locks. They require a combination of numbers that only the owner knows, so if a thief tries to guess the combination of numbers, they would take a very long time to work through the correct code.