Key Stage 2 Primary Projects

Cam Castle

This cams project was originally linked to the Knights of the Round Table, where the basic cuboid became a castle and the knights were moving with the cams on the battlements. With a few changes this could be linked to literacy and illustrating a story of anywhere that movement can be used, by attaching a geared motor and battery pack these models make a fantastic display.

The cams rely on a steady movement, a large foot on the follower and the follower held vertically above the cam. By building a framework and using TechCard to give solid axle supports you can create a firm base and by adding in the ClunkClick motor, the shaft revolves at a sensible speed to allow the cam followers to lift up and down.

The movement of the flags is different depending on the shape of the cam.
This shows the followers resting on the cams.
The two strips of the TechCard across the frame hold the followers vertical and ensure that the followers rest on top of the cams.

It is often thought that cams will give all sorts of movement, but in machines cams are usually used as a form of switch to control a part of the machine. Cams transform rotational movement into reciprocating movement. The movement is usually very small and rapid and so is not conducive to display models. However with a careful modelling it is possible to create a smooth running and interesting display and when motorised the animation is very attractive.

Cuboid Diagram

You can use your own dimensions to create the required cuboid.

This set of videos helps you understand how to make the cuboid.

To be able to make rectangle, ie all 4 corners, in one go, then the minimum size for the smaller side pieces is 115mm. this will give a finished size of 135mm because the longer pieces will overlap the shorted pieces and the Lynks jigs will fit side by side.

As in the cutting list you can create your own sizes.

Have a look at to see the secrets of cams.