Castor:
Castor is an oil! :-)
Caster is a measurement taken in the steering.
viewed from the side the kingpin leans back with the top closer top the driver than the bottom.
This has three effects.
1) when the steering is turned the wheel describes an arc that is higher toward the front of the kart and lower towards the rear.
This means that the inside wheel presses down towards the ground and the outside wheel lifts up from the ground.
If the 'weight' in the kart is transferred to the front of the kart, as in braking, the front wheels stay in contact with the ground and the inside rear wheel lifts.
If the 'weight' in the kart is transferred aft, as in accelerating, the rear wheels sit straight on the ground and the outside front tends to lift.
by increasing the angle of the caster, the rear wheel can be made to lift higher, meaning it leaves the ground earlier and the kart turns in more easily.
2)Caster Trail. The inclined king pin will point at a spot ahead of where the tyre touches the ground, the perpendicular from the centre of the stub axle. This is the 'trail distance'.
The longer the trail distance the more the wheel will try to 'follow' the straight line. The steering will tend to self centralise and be harder to turn into the corner.
3) Turn Camber. The wheel is following an arc at an angle to the horizontal. This means the camber will change as the wheel turns. The inside wheel will gain positive camber and the outside wheel will gain negative camber.
Camber
Camber is the angle of the wheel relative to vertical, as viewed from the front or the rear of the car. If the wheel leans in towards the chassis, the tops of the wheels are closer together, it has negative camber; if it leans away from the car the tops are further apart, it has positive camber
A vehicle develops the greatest cornering force at about -0.5 degrees (half a degree Negative Camber).
when a driver sits in the kart, his weight will tend to bend the centre of the kart down and increase the negative camber.
The idea is to adjust the camber so that when the kart turns, it has -0.5 camber.
Obviously cornering forces create dynamic camber changes that make the setting up of the kart different for each driver and each track.
Look at http://www.ozebiz.com.au/racetech/theory/align.html
to get some idea, remembering that cars have more suspension than karts but we have relatively more tyre than most cars do.
Does that help?
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Iame Cadet Castor/ Camber by 'PennyLessDad' (23 Jun 2015 @ 20:21)
