Gearbox

1. A gearbox for a model car, comprising:

a housing;

an input gear; and

an output gear;

in which the housing provides a support for each of the input gear, the output gear and at least one intermediate gear; and in which the gearbox has:

a first operating configuration where the input gear, the output gear and intermediate gears are supported by the supports and mesh to form a gear train from input gear to output gear through each intermediate gear supported by the supports; and

a second operating configuration where the input gear and the output gear are supported on the supports and fewer intermediate gears are supported by the supports with respect to the first operating configuration, such that the input gear, the output gear and the intermediate gears supported by the supports mesh to form a gear train from input gear to output gear through the intermediate gears.

2. The gearbox of claim 1 , in which the difference in the number of intermediate gears supported on the supports in the first and second operating configurations will be an odd number, such that the first and second operating configurations provide rotation at the output gear of opposing senses for the same rotation at the input gear in the first and second operating configurations.

3. The gearbox of claim 1 , in which the support for at least one intermediate gear is arranged to support an intermediate gear in a different position within the housing in the first operating configuration and the second operating configuration.

4. The gearbox of claim 1 , in which the input gear is provided with teeth and a clutch having an input, such that torque input at the input in a given direction to the input gear will cause the clutch to lock the input relative to the teeth, and torque applied to the output gear in a direction tending to otherwise rotate the input gear in the given direction will cause the clutch to slip and allow relative rotational movement of the input and the teeth.

5. The gearbox of claim 1 , in which the output gear is provided with a differential having two outputs, the differential allowing the two outputs to rotate relative to each other and still be driven by rotation of the output gear.

6. A drive mechanism for a model car, comprising a motor having an output shaft and a gearbox according to claim 1 , in which the output shaft of the motor is coupled to the input gear of the gearbox.

7. The drive mechanism of claim 6 , comprising at least one output for coupling to a driving axle of the model car.

8. A model car, comprising the drive mechanism of claim 6 and at least one driven wheel, each driven wheel being driven by a driving axle coupled to an output of the drive mechanism.

9. The model car of claim 8 , in which the drive mechanism is provided such that the motor can be mounted on the car in a mid-motor position, where the motor is forward of the driven axles, and in a rear-motor position, where the motor is backward of the driven axles.

10. The model car of claim 8 , in which the drive mechanism is provided such that the motor can be mounted in the car with the output shaft extending towards either lateral side of the car.

11. A method of configuring a gearbox according to claim 1 , comprising changing the gearbox between the first and second operating configurations by at least one of adding and removing intermediate gears.

12. The method of claim 11 , comprising moving at least one support for an intermediate gear within the housing, so that the gear train meshes.