Monday, 14 March 2011

Ackermann Steering

The Ackermann steering principal was invented by the German ( no surprise there!) Carriage Company Lankensperger in 1817 and then patented by their agent Rudolph Ackermann in England. Why this system was worked out and applied to a horse and cart, I really have no idea. But the basic principal is that when steering wheels turn, the inner wheel should scribe an arc of a smaller radius than the outer. To achieve this, the steering arms are angled inwards and by projecting a line backwards from both arms, the point where they meet should be dead centre of the rear axle. This creates a differential and causes the inner wheel to turn slightly more than the wheel on the outside. I have endeavoured to produce a unit to fit a slot car chassis. In particular the PCS 32 chassis although I guess it will fit a Slot Classic unit in just the same way. The unit is produced using the trusty photo etching method and is made from .55mm brass. It comprises four parts as shown. The main cross piece which is folded in two planes to form a channel section and carries the four "wishbones". Two uprights are fitted into .55mm holes in the ends of the wishbones, with the whole piece being held together by the tie bar. A tab at each end of the tie bar is bent over to keep everything as one.
The uprights need to have the axle "bearings" soldered in and these will be made up from two 3mm lenghths of 3mm o/d brass tube. The stub axles are being made up from steel.

The complete unit moves very freely. An important point in any trail steer unit, but there is no slack, with the whole piece being quite a precision item.
How it performs, I have yet to find out, but if it works half as good as it looks, i'll be very pleased.


  1. Beautifully made. It will be very interesting to see how it will fit the chassis.

  2. Gorgeous. How much does it weigh?