Drive System
Ruf Ruf Dougal has two central drive wheels, which steer by differential speed. The front and back of the armour is supported on small castors.
Motors
The drive starts with two car electric steering motors which weigh 2.9kg each. They have an in built friction clutch set to 9Nm and run at 1800rpm. Over running them at 24V gives a rotational speed of 3600rpm. At clutch slip the motors are taking 120 amps.
Transmission
Drive is by derailleur bicycle chain using a 5 speed block with the freewheel pegs removed as a lay shaft. The chains are tightened by twisting the motors and eccentric wheel spindles. To give lateral chain support nylon guides are positioned either side of each chain.
Drive Ratio |
||
11 : |
28 x 14 lay shaft block |
: 24 |
Wheels
Wheels The wheels are made from dia 125mm rotary wire brushes with side support plates. The whole wheel was then dipped into molten bitumen to give the bristles support.
 |
 |
| Motor and Layshaft | Eccentric Wheel Spindle |
 |
 |
| Layshaft | Motor Mounting |
 |
|
| Chain Guides |