How to Build a Cardboard Robotic Arm

There are few costume items more iconic than a robot arm. Robotic arms are kitschy, cool, and easy to make with nothing but cardboard, duct tape, and a pair of good scissors. Wear a metallic jump suit and some silver face paint, and you've got a great last minute costume.

Things You'll Need

• Scissors
• Knife
• Duct Tape
• Cardboard Tube
• Cardboard Sheet

Instructions

1. Get a cardboard tube wide enough to fit over your forearm. Poster tubes work very well because they tend to be thick and durable.

2. Cut the cardboard tube to the desired length. It should be at least as long as your forearm.

3. 

   Cut two pieces of cardboard into the shape of a v with a flat bottom. The length of the bottom should be about 11/2 times the diameter of the cardboard tube.These pieces will be used to make the robot hand.

4. Bend both pieces in half to create a crease along the center line.

5. Lay the cardboard pieces on top of each other so that they are aligned.

6. Tape the two pieces together at the left and right edges. Do not tape the bottom.

7. Fit the hand inside the end of the tube. It will bow outward along the creases, forming a diamond-like shape.

8. Use tape to secure the hand inside the tube and reinforce its shape.Using silver duct tape will also give the hand a robot look.

9. Wrap the arm in silver duct tape.

Tips & Warnings

• You can use metallic paint instead of duct tape, to give the robotic arm a more polished appearance.