Page 140 - Making things move_ DIY mechanisms for inventors, hobbyists, and artists

120 Making Things Move

• Ping-pong ball

• Duct tape
• Hot glue gun (with glue)

Recipe:

1. Line the edges of the CDs with duct tape to give them some traction.

2. Cut a 4 in length of the wooden dowel with your knife and file any splintered
ends.

3. Attach the laser-cut hubs to the CDs with hot glue. Alternatively, use epoxy
putty to bridge the gap between the wooden axle and the hole in the CD.

4. Gently insert the wooden dowel into the laser-cut hub on one wheel. It should be
snug. If it’s too loose, wrap the dowel in a little duct tape and try inserting it again.
If it’s too big, use the file to sand down the end until it fits (see Figure 5-12).

5. Twist the eye screws into the side of the mousetrap opposite the “bait” hook.
They should be as close to the edges as you can get them without splitting
the wood.

6. Duct tape the mousetrap down to one end of the paint stirring stick.

7. Insert the wooden dowel with one wheel attached through the eye screws,
and attach the wheel on the other side.

8. Duct tape the ping-pong ball under the other end of the paint stick, and your
car should balance.

9. In order to stop the wooden dowel from sliding back and forth, wrap strips of
duct tape just inside the eye screws around the dowel. The dowel should still
spin freely.

10. Cut at 2 ft length of fishing line. Tie one end around the center of the wooden
dowel. Tie the other end to the center of the mousetrap arm. Secure with
duct tape if necessary.