Effector

Materials:
2 Styrofoam coffee cups
string (3 colors if possible)
tape
small cardboard box
scissors
ruler
sand paper
balloon
Velcro square
thick dowel 2-3" long

Advance Preparation:
For younger campers, mark where to cut each cup.
Attach opposite side of velcro square to a blown up balloon and a small cardboard box; attach thick dowel to the balloon on the side opposite the Velcro.
Make mission cards by copying the scenarios onto 3" x 5" cards.

Procedure:

1. Cut off the bottom (closed end) of 1 cup. Discard it. (See Figure 1).
2. Turn a second cup so that its opening is on the table. Place the 1st cup over the second cup and trace a line on the outer cup using the inner cup as a guide (So that the cut edges of the cups are the same height when nested one inside the other as in Figure 2). Cut the cups along this line and discard the sealed end. Smooth the edges with sandpaper, if necessary. (You should now have what you see in Figure 3.)
3. Cut three pieces of string 12 cm long.
4. Tape the end of the first string to the inside of the inner coffee cup, close to the cut edge.
5. Tape the other end of the string to the outside of the cup (forming a loop that does not cross the opening) but do not press this piece of tape tightly yet.
6. Repeat steps 4 & 5 twice more, but place the strings about 1/3 of the way around the cup from the first string. (You should end up with the what you see in Figure 4.)
7. While holding the rim of the inner cup, rotate the outer cup until the three strings cross each other. The strings will have some slack.
8. Pull the end of the strings on the outside until they are straight and intersect exactly in the middle of the cup opening. You can now press the tape on the outside to hold the stings in place.
9. Use the effector to pick up a pencil with the help of a friend. (Your friend should hold the pencil upright while you use the effector to grab it.)
10. Use the effector to move a Space Station Component (balloon on dowel) from the Space Shuttle to the International Space Station (cardboard box).

You may want to make a maze of cups and challenge campers to move a ball through the maze touching it only with the effector. The cups will need to be taped in place on the floor and the ball should be larger that the mouth of the cup, but small enough to be picked up with the effector.

You may make two mazes and have races to see who can complete the maze the fastest.

You may use larger balls or balloons for the maze if you attach paper straws or cardboard tubes to them.