Introduction: Cardboard Catapult

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Hi!

This is a really cool catapult that really works, too!

Catapult Tools

· Hot glue gun, ruler, box cutter or scissors, pen or pencil

Catapult Materials

· Qty. 1 Rubber band

· Qty. 1 Marble or small ball

· Qty. 1 Wooden dowel (12” long, ¼” diameter)

· Qty. 4 Popsicle sticks (1” x 8”)

· Qty. 4 Popsicle sticks (1” x 4”) made by breaking two 1” x 8” popsicle sticks in half

· Qty. 1 Corrugated cardboard rectangle (12”x 4”)

· Qty. 1 Corrugated cardboard rectangle (3.5” x 3”) with ¾” x ¾” squares removed from two corners as shown

· Qty. 3 Corrugated cardboard rectangles (4” x 8”)

· Qty. 4 Corrugated cardboard right triangles (base = height = 6”)

· Cellophane tape

Step 1: Build the Fulcrum

Glue two of the 6” triangles together using hot glue. Do the same with the other two 6” triangles.

Step 2: Assemble the Base of the Catapult

Glue the three 4” x 8” rectangles together using hot glue.

Step 3: Make the Arm of the Catapult

Fold the 12” x 4” along its length to form a tube of square cross-section . The tube is 12” long and has four 1” wide sides. Glue the tube along the 12” edges.

Step 4: Form the Catapult Projectile Holder

Fold the sides of the 3.5” x 3” cardboard cutout to form a box. Hot glue the sides together to hold the shape of the box. You can use tape to hold the box together while you apply the hot glue.

Step 5: Make a Brace for the Bottom of the Catapult

Glue two 1” x 8” popsicle sticks together and glue them perpendicularly to one of the 4” edges of the 4” x 8” cardboard.

Step 6: Install the Reinforcement Sections for the Bottom of the Catapult

Glue two of the 1” x 4” popsicle sticks together using hot glue and glue them onto one of the centers of the long edges of the 4” x 8” cardboard. Hot glue the other two 1” x 4” popsicle sticks together and glue them on the other edge of the 4” x 8” board.

Step 7: Make the Spring Retainer

Hot glue the two last 1” x 8” popsicle sticks together and glue them perpendicularly onto the center of the last edge of the 4”x 8”board. The sticks should stick out about 5” or 6”.

Step 8: Install the Fulcrum

Hot glue the triangle cardboards to either side and on the topside of the catapult bottom.

Step 9: Fabricate the Pivot

Make small holes in the two triangles near the tops and make a small hole in the 12” long tube so that the tube sticks out over the popsicle stick about ½”. Put the dowel through the triangles and the tube.

Step 10: Install the Projectile Holder

Hot glue the box onto the end of the tube that is opposite the popsicle stick that sticks out.

Step 11: Install the "Spring"

Put the rubber band around the tube and the popsicle stick that sticks out. Use cellophane tape to hold the rubber band in place.

Step 12: Enjoy!!

Put the marble into the box and push the box down. When you let go, the box will fly up and the marble will fly across the room.