How to Design Mechanical Movable Toys

Remove the cap from the cigar tube. Remove the cigar and put it and the cap aside. Place the cork on the work surface. Hammer the nail through the center of the cork with the hammer. Pull the nail out of the cork.

Place the balsa wood horizontally on the work surface. Spray the balsa wood with the waterproof spray can. Let the wood dry. Turn the wood over and spray the side that is now facing up. Let the wood dry.

Cut in from the top and bottom at one end of the balsa wood to form a point, using the blade of a utility knife.

Place a teacup candle on each end of the balsa wood, 2 inches in from the outside edge. Tape the bottom of each candle to the balsa wood, using strips of duct tape.

Measure 1 inch in from each end of the cigar tube. Make a dot at this point with a pencil.

Wrap half of each wire around each dot on the tube. Fill the cigar tube almost full with hot water. Insert the cork into the open end of the cigar tube.

Place the cigar tube over the balsa wood, with the cork facing the end opposite the point. Wrap each of the wires wound around the tube around the balsa wood. Twist the two ends of each wire together.

Pull the tube up so that it is an inch or so above the tea candles. Fill the bathtub with water. Carefully place your steam rocket on the surface of the water.

Light both of the teacup wicks with a match and watch the steam exit the cork and propel your toy rocket boat forward. Blow out the candles when you are done, and let the tube cool off before removing the boat from the water.