Car transport semi truck.

This model was built late 2000. I have always had the idea of seeing how many cars I can pack on a truck. I still think about it, and other attempts will follow. My limiting factor here was the number of wheels (for the cars). 

This model is powered by two 9V "gear reduced" motors, steering is done with a regular motor. The tractor also has an on-board compressor to run the pneumatics. 

	The compressor is hidden in the very front of the cab, in front of the front axle. You can see the driving motors in front of the rear wheels (behind the air tanks); one on each side of the chassis.
	You can see the differential connecting the two driving motors (and therefore allowing a low/high gear setting by powering one or both motors). The steering motor is between the air tanks. It is a regular 9V motor: I only have 2 geared-down motors, and with the weight on the front axle, the micromotor would not turn the wheels.
	Here is the finished truck. A simple pneumatic system raises and lowers the rear half of the top deck for loading/unloading. The trailer has a stand that can be raised/lowered manually.
	The seven cars are waiting to be loaded. The sloped bricks on the trailer hold the cars in place (that was an easy way for me). The air switch is on the trailer chassis (just above the blue car's roof).
	Loading up the cars. After trying different combinations, I found four cars that would fit on top without touching each other's bumpers.
	Most amazing to me is that not only the pneumatics worked good, but the motors could move the truck when fully loaded (although crawling is more appropriate than moving).
	The gearing down mechanisms for the steering and the driving both include in some point a sliding axle, so that the motors can be "disconnected". The model can then be moved by hand (the steering wheel is the light on top of the cab).