PROJECTS: HHO ROCKET
makezine.com/20/hhorocket
3d. Cut six ½" pieces of vinyl tubing and glue them to the bottom
and middle of one bottle, 120° apart between the fins. This will be
the upper stage.
3e. Glue three ¼" dowels 18" long to the sides of the other bottle,
120° apart between the fins, starting halfway up the bottle. Use
the launch pad to hold the rocket during construction. Use 3
rubber bands to hold the dowels in place while the glues dries.
This will be the lower stage.
4. MAKE THE IGNITERS
Prepare each igniter carefully because if it doesn’t fire, the rocket
stage won’t ignite.
4a. Cut a wedge into one end of the 10"-long ¼"-diameter
dowels. Cut 2 feet of twisted wire, align the wire with the wedged
edge of the dowel, and tape the wire 1" below the end of the
dowel. Wrap the wire around the dowel, pass the excess through
the rubber stopper hole, and then pass the other end of the
dowel through the rubber stopper hole.
4b. Strip the ends of the wire taped to the dowel with a razor
blade or knife, twist them to the leads of a rocket igniter, and
tape them to the wedge with the chemical tip exposed.
5. ASSEMBLE THE STAGE SEQUENCER ELECTRONICS
5a. Use a pencil eraser to clean all the copper on the circuit
board.
5b. Solder the sockets in place, then the components. For all
electronics connections, refer to the schematic diagram at
makezine.com/20/hhorocket.
Photography by Tom Zimmerman and Ed Troxell (above this page and bottom facing page)
96 Make: Volume 20
