The steer ability of equipment and machinery is depending on the position of the individual wheels or castors under the respective device(s). Various formations are possible in order to show the direction in which it should go:
Four casters at the same height with the same structure.
This is the optimal formation in order to be able to move in all directions. However, in narrow passageways when moving straight ahead this formation makes the equipment difficult to stir. By installing a fixing device at least on one castor, this can optimized the behaviour of the equipment/device.
Two swivel wheels and two fixed wheels at the same height with the same structure.
Probably the most common formation for wheels, suitable for the most diverse applications, namely to move straight ahead and for routes with many bends. As an alternative, it is possible to install a set of castors or two wheels on an axle, instead of a fixed castor. This construction, however, remains problematic with narrow passageways.
The following figures give an overview of the most common wheel arrangements with the related load expressed as a % age of the total load.
1) 1 Swivel and 2 fixed castors Suitable for small loads. Easily manoeuvrable but unstable.
2) 4 Swivel castors Easily manoeuvrable in all directions, but difficult to handle in a straight line.
3) 2 Swivel and 2 fixed castors Easy to steer in a straight line, but less flexible when changing direction.
4) 4 Fixed castors and 2 central higher Easy to steer in a straight line. Easily manoeuvrable but unstable.
5) Recommended for heavy loads and long vehicles. Easily manoeuvrable in all directions and good
handling in a straight line.
