3D MODEL DESCRIPTIONA tractor with a rotating engine, 4 pistons go up and down when the crankshaft rotates, the fan in front rotates with a set of two normal gears, the steering wheel rotates a set of two gears at 90 degrees, producing a rotation of the front wheels. Both the rear arms are free to move and the power transmission which is at the back. All the parts are glued (preferably with epoxy glue that comes in the form of a double syringe to prevent the internal parts from sticking if you use liquid 3-second glue), you need a rod with a diameter of 2 for the axis of the engine hood and the axis of the fan, you can also use a small nail, you need two small springs of a simple regular pen, the springs are used to push the pistons down, you have to cut them in half and glue them to the cap, there are exact instructions for assembly in the folders I have attached, if there are any questions I will be happy to help,