Tractor challenge

Until the early part of the last century, farmers used horses or oxen to pull carts and help plough the fields. Now tractors are used to do this … and for lots of other purposes as well. Could you make one?

Levels of difficulty:

Level 1 - Make a simple model of a tractor.
Level 2 - As level 1, powered by a battery motor.
Level 3 - As level 2, with a plough on the back, and the plough the sand in a sandpit.

Equipment: K’NEX set including small and medium wheels, plus a battery motor and (for level 3) a sandpit.

Approach: What does a tractor look like? What type of wheels does it need? Where does the driver sit? For level 2, how can you make the motor drive the wheels? How will the motor be fastened to the body? For level 3, what is the purpose of a plough? How can you make one out of K’NEX? How will it attach to the back of the tractor? Does it work when tested in a sandpit?

Handy Hints (please click to view):

A2 - 3 ways to connect K'NEX rods and connectors
A4 - Making corners with blue & purple connectors
W5 - Wheels and tyres
W6 - Making rods turn with wheels or connectors
M2 - Tethered battery motor