Oshkosh 8x8 off-road truck
The model has two coupled XL-motors for driving the eight wheels and one S-motor for steering the front two axles.
Another two S-motors are used for the outriggers. They cannot be extended, but just go downwards.
One S-motor is used for the rotation of the crane and two more S-motors are used lifting and tilting the crane and the last S-motor is for extending the crane. Nine motors in total, with two battery boxes and all remote controlled using five receivers.
The coupled traction motors are connected to separate receivers and battery boxes for more power!
Manual functions are lowering the spare tire and rotating the winch on the crane.
All wheels have independent suspension and the doors and hoods (on both sides of the motor on top) can be opened.
The crane is operated by four cylinders, linear actuators in this case and the bottom hinge of the first two cylinders is connected with the top hinge of the second two cylinders. The cylinders are driven two by two. Thus it is possible to make any tilt movement that you want!
You also see the outriggers here in the down position. The are driven by helical gearing.
Here you see a close up of the actuators. The two driven shafts go through the center of the turntable, so that the whole construction can rotate as well.
In the chassis picture you see the location of some of the motors. From left to right: the steering motor, one of the XL traction motors, the right outrigger motor and one of the two crane tilt motors.
The lowering of the spare tire, a manual operation. The Lego motor is underneath the black covers behind the cabin and the cylinders move up and down as the truck is moving. The covers can be opened as mentioned before.
The traction of the eight wheels is with helical gearing, so no differentials used. This makes the truck slow, but very strong.......really a crawler truck!
If this would become a Lego set, then most functions should be manually otherwise the set would be too expensive. Would be nice to operate the crane remotely and you only need four small motors and two receivers to do that.
Hope you enjoy the model........a YouTube of the model in action will follow soon.