[Lynn Eades]

Your cam plate is mounted on a bearing on a stub axle on the floor. when the steering turns the cam plate, it shifts the cross tube(via the rollers) to one side, (say left) this moves your double bogies all to the left,distorting the centre of the track to the left. (max 3/8 inch) causing the carrier to turn slightly to the right(15 degrees) To explain that a bit more the carrier follows the direction of the curve in the track as it would appear if you were looking down from above. (if you observe a couple of "in use" track links on the pin, you will notice the lateral clearance which allows the links to shift sideways.)To make your right turn tighter you would turn the steering wheel further to the right.This brings into play the appliction of the right brake.

One of the Aussies should be able to post pictures and diagrams to explain all of this.

When you have it all figured out how it all works then you will understand why the adjustments are so important for the smooth functioning of the whole deal.
Hope this helps