The position of the chassis rails at the front means a conventional double bellcrank steering arrangement is impossible. If double bellcranks were fitted, they would be spaced so far apart that there would be far too much bump-steer. I had to think of another way to move a steering rack from left to right. I spent some considerable time working out a hydraulic arrangement using a double-acting ram. In the end I went with what I thought would give less maintenance hassles. A linear steering rack slides in a delrin bearing block. The rack is dragged with a fine steel cable normally used for model aircraft closed-loop rudder systems. To get the required travel, the cable is attached to a large pivoting beam made of carbon fibre. This is rotated by the servo via a heavy duty servo saver. The end result is a lot of steering travel with very little play in the system.
Steering rack and bearing block. The grooved pulleys guide the steel wire onto the rack.
The completed steering assembly.