Lego Tractor

Cyrus Tabrizi, 6/28/12

    This was my entry to the "Farming" category of the Technic Challenge. It is a tractor with remote controlled steering, rear-wheel drive, and a working bucket lift. One XL motor powers the rear axle of the tractor through a worm gear and a differential, providing it with plenty of torque (1:9) but a rather low speed. Although slow, the ratio is consistent with that of a real tractor. The front axle is steered by an M motor through a gearbox (1:2.7). This gearbox is positioned behind the front axle and fits within a slim undercarriage. The steering runs quickly but is slow enough to be controlled with a standard PF remote. The main tractor arm is powered by a second XL motor and two linear actuators. This motor is mounted in the arm and, consequently, the linear actuators are driven from this arm, not from the chassis. The drive and steering motors are responsible for this positioning. Another M motor (housed under the arm's XL motor) powers a third linear acuator responsible for controlling the arm's bucket. A conveyor belt on the side of the tractor's arm contorts to the angle of the arm through soft shock absorbers and liftarms. It serves no practical purpose, but adds to the tractor's unique appearance. The tractor also has working headlights in the front, and a compartment for holding grain or other crops in the rear. The cabin opens upwards. Check out the video below to see it in action!

More pictures can be found on Flickr.

AutoTRACTOR 3000
Tractor (140)
Tractor (129)

This picture shows the XL motor and related mechanisms that are responsible for lifting the tractor's arm

Tractor (145)

Here you can see the tractor's bucket and the linear actuator that tilts it

Tractor (100)