Building an air cart
To build your air cart follow these easy steps!
Carefully use the utility knife to cut out a 12cm x 40cm rectangle from cardboard for the air cart body. The corrugations in the cardboard should run the long way. Your teacher may provide this cardboard piece already cut.
Mark the slot for the SmartWheel. Be sure the slot is parallel to the cart length. The slot is 2cm wide and 14cm long, starting 4cm from one end of the cart and 5cm from each side.
Cut out the slot with a utility knife. Please be very careful!
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Mark the axle line. It is 8cm from the other end of the cart and perpendicular to the long side. You can use the corner of a piece of paper to make a perpendicular line.
Glue the straw to the axle line with hot-melt glue. Let it stick out on either side.
Cut off each end of the straw a bit longer than the cardboard.
The finished straw is now ready for the axle.
Center the SmartWheel in the slot so that it doesn't rub against the cardboard. Make it exactly parallel to the long edge of the cart. This will make the cart go straight. The aluminum arm goes against the same side of the cardboard as the straw. Mark two screw holes with a pencil or pen, one at each end.
Make holes where the marks are, using a pencil or pen point. Enlarge the holes from both sides, until the screws fit snugly into them. The screws are provided with the SmartWheel.
Put the screws first through the cardboard from the other side, and then screw them into the arm of the SmartWheel. Tighten them until the heads squeeze the cardboard a little bit. A paper clip will work as a screwdriver.
Now the SmartWheel is in place. It can be taken on and off. You will need to do this for the Tracker Investigation.
Snap each CD ROM wheel onto a black hub, if this isn't already done. Put the hub on a table with the tapered end pointing up, and push the CD wheel down, snapping it into place.
Push the aluminum axle into the black hub on one CD ROM wheel. The long tapered end of the black hub should face toward the cart.
Slide the axle through the straw and then slide on the other CD ROM wheel. The picture shows the cart upside down.
Glue the bumper in the center on the front end that contains the SmartWheel end.
a)Glue the motor on the back end, in the center, with its body sticking out a little bit beyond the cardboard. Use plenty of glue.
Place the batteries in the battery holder. Make sure the batteries are loaded in opposite directions in the holder. Glue it down in the center next to the motor. Leave a little bit of space between the battery holder and the motor.
Glue down the paper cup in the center right behind the SmartWheel slot. Make a lump of clay so that you can add weight to the cart.
To make the swinging bar for the acrobat, first bend the wire into a "U" about 6cm wide and 17cm long.
Bend up the ends of the "U" and crimp them a little bit. Each crimped end should be about 4cm. long.
Slide the crimped ends into the corrugated cardboard. If the ends of the wire are crimped, they will fit snugly into the end of the corrugated cardboard and stay firm during collisions. The acrobat needs to be removed when you mount the Force probe on the cart.
Put bits of clay into the acrobat's hands so that it has a good grip. Hang the acrobat on the wire.
Decorate your cart to your liking...
