The simplest definition of the word "machine" is "any device that is designed to make work easier." (Reference 1). There are six types of simple machines: the lever, wheel and axle, screw, wedge, inclined plane, and pulley. These devices, in one form or another, form the basis for almost every machine that is used in daily living, from cars to elevators. You can make a "complex" machine using all six of the simple machines.
Saw one of the plywood boards in half diagonally, making two large triangles. Lay down another plywood board and nail both triangles to the board standing up and at right angles, one to the left side and the other to the right side. Then, nail another board to the back of the triangles. You should have made a shape that looks like a trapezoidal trough, somewhat similar to the bucket in the bulldozer below. Allow the entire structure to set until hard and sturdy.
Saw a one-foot piece from the wooden dowel and nail it to one side of the trough as a handle. This is the lever.
Nail together six boards to form a wooden box. Lay down one board and nail four boards, all vertical, on each side of flat board. Nail the sixth board to the top. You may have to saw some of the boards so that they fit on the board without any overhang. Nail a seventh board to one edge of the top of this box. Nail the board at an angle (the degree of the angle is your choice) so that the board forms an inclined plane.
Screw one end of both door hinges to the top of the box on the side directly opposite of the inclined plane. The hinges should be screwed on so that they bend upward towards the inclined plane. Screw the trapezoidal trough to the other part of the door hinges. You should now be able to pull the lever on the trough so that it comes forward toward the inclined plane.
Cut off a 10-foot long piece of rope from the long coil. Place the rope in the pulley. Tie the end of the rope to both of the buckets. Hang the pulley from a 12-foot tall tree branch or other sturdy structure of similar height.
Tie the remainder of the rope to the garden hose reel and roll it up so that the rope is completely around the reel. Tie the free of the rope to the plastic bucket that is on the left side of the pulley. Adjust the pulley so that the bucket on the left hangs down about eight feet and the other bucket hangs down two feet.
Position the ladder so that it is beside and about two feet away from the bucket on the right of the pulley. Carry the wooden structure from Section 1 up to the top of the ladder and place it on top with the inclined plane hanging directly over the right bucket.
Retrieve the basketball and carry it to the top of the ladder. Place it inside of the triangular trough. Turn the lever of the trough so that the basketball falls over towards the inclined plane. The ball should roll down the inclined plane and land in the bucket, pulling it down and pulling the left bucket up which will act on the rope and move the garden reel. The garden reel can then be turned to pull the rope back and reset the experiment. Keep trying until you get all elements perfectly in sync.
This machine is designed to demonstrate the action of all the simple machines working together. The lever, screws (in the hinges), wedges (nails in the wood), inclined plane, pulley and wheel and axle (garden reel) all work together to move the basketball and pull on the rope. This experiment is best performed outside and with at least one adult, if children are involved.
Tips and warnings
- This machine is designed to demonstrate the action of all the simple machines working together. The lever, screws (in the hinges), wedges (nails in the wood), inclined plane, pulley and wheel and axle (garden reel) all work together to move the basketball and pull on the rope.
- This experiment is best performed outside and with at least one adult, if children are involved.
Things you need
- 10 plywood boards, 1 square foot each
- Circular saw
- Wooden dowel, 3 feet long, 1 inch in diameter
- Box of 1-inch-long nails
- 2 door hinges
- Power drill with screwdriver attachment
- Box of 1-inch-long wood screws
- 50 feet of 1/2-inch-wide rope
- 2 large, plastic buckets
- Large ladder
- Garden-hose reel