A swash plate cam is usually a disc that rotates around a shaft. The disc is set at an angle so that the follower moves up and down as the disc rotates.

The example below shows how two followers can be used resting on the same swash plate cam. Each follower has a wheel or roller that allows smooth movement.

A mechanical toy is seen below. As the swash plate cam rotates (driven by a small motor), the two roller followers rise and fall. This motion makes the model look as if it is lifting weights / exercising. The cam mechanism would normally be ‘boxed in’ for safety reasons. However, on the drawing below the front has been removed so that the mechanism can be clearly seen.

Swash cams have ‘roller’ followers, because they ‘act like wheels turning as the cam rotates. A flat follower would jam / fail as it would create too much friction between the follower and the cam.

The low voltage drive motor is connected to the swash cam by a pulley system. This means that the motor can be positioned away from the moving parts. A small pulley is connected to the motor and a larger pulley to the cam. This slows down the cams rotation. If pulleys were not used, the rotation of the cam would be too fast.

QUESTIONS:
1. How could the flat swash plate cam be modified to produce an even more interesting movement of the followers? Draw a diagram and add explanatory notes.
2. A piece of rectangular transparent perspex is used to cover the front of the mechanism - for safety reasons. This means that young children are not able to ‘trap’ their fingers in the mechanism. Draw a diagram(s) to show how the perspex is fixed in position. It must be possible to remove the cover for lubricating the mechanism but only if appropriate tools are used.