1930s Amilcar

Front beam axle. With the chassis sitting on its rear wheels and level, the front wheels were propped up so the steering hubs were at the right castor and camber angles for the build. We’ve selected a castor value on the high side of typically recommended values to bias the steering towards tracking stability. With the wheels set at the right angles, a pattern capturing the locations of the bottom of the springs and the steering knuckles was made using fibreboard and hot glue. With the pattern capturing the geometry the beam axle was built up from square steel tubing, steel plate cut to the shape of the curves up to the knuckles and steel strap top and bottom to tie everything together. After the beam was fabricated, we set the wheels up again to check the geometry was right then tacked the steering joints to the beam. With the wheels attached the kart could be rolled forwards despite the wheels not being tied together. We took that as a sign that the castor of the steering will work for us.