How to Make a Potato Launcher

Built properly, a potato launcher can be used to fire spuds hundreds of yards at a time.

Who says you can't play with your food? Potato launchers are a fun way to demonstrate the scientific concept of propulsion with a device that can fire spuds hundreds of yards, dazzling friends, family and science fair crowds alike. Because potato launchers, sometimes called "potato cannons" or "spud guns," can be quite powerful, an adult should always be present when they are being built, but once assembled, potato launchers can lend themselves to hours of fun with spuds.

Things You'll Need

• 2-foot piece of PVC conduit, 4 inches wide
• Towel
• Rubber cement
• 1-inch wide wood paint brush
• 4-inch wide female PVC adapter
• 4-inch wide threaded plug
• 4-inch wide PVC coupler
• 4 to 2-inch PVC reducer
• 5-foot piece of PVC conduit, 2 inches wide
• Handheld drill
• 1/4-inch drill bit
• Spark generator
• Electrical tape
• 10-pound bag of potatoes
• Broomstick (optional)
• Aerosol starting fluid
• Plastic safety glasses (optional)
• Construction gloves (optional)

Instructions

1. Clean around the edges of the 4-inch wide PVC conduit using the towel. Apply the rubber cement around the outside edge of one end of the conduit using the paintbrush and attach the female PVC adapter to the glued end of the PVC conduit. Insert the threaded plug into the female adapter to form an end cap.

2. Apply rubber cement around the outside of the opposite end of the 4-inch wide PVC conduit. Attach the coupler to the glued end of the conduit. Apply glue inside the end of the coupler not attached to the PVC conduit. Attach the reducer to the coupler.

3. Spread glue around the inside of the hole in the reducer opposite the side attached to the coupler and plug the 2-inch wide PVC conduit into the glued end of the reducer. Allow the glue to dry for a full 24 hours.

4. Drill a hole into one side of the 4-inch wide PVC conduit using the drill and drill bit. Insert the spark wire of the spark generator through this hole and test the spark generator. You should see a spark appearing in side the potato launcher below where the hole is drilled. Attach the spark generator to the side of the 4-inch PVC conduit using electrical tape.

5. Add the potatoes to the launcher by standing the launcher vertical so the end cap is on the ground and pushing the potatoes down the barrel, using a long stick such as a broomstick, if necessary.

6. Flip the potato launcher over and unscrew the end cap attached in Step 1. Spray the starting fluid into the launcher's barrel for about 1/2 a second. Screw the end cap back into place.

7. Balance the potato launcher on one shoulder and aim it away from people, animals and objects that could be severely damaged. Pull the trigger of the spark generator to ignite the starting fluid and launch the spuds.

Tips & Warnings

• Potato launchers should only be fired by teenagers and adults, as the firing mechanism generates a "kick" that could knock over children.

• Wearing plastic safety glasses and construction gloves is recommended when assembling and using the potato launcher to prevent fragments of potato or PVC piping from causing serious injury.

• The cement used in Step 1 through Step 3 must be allowed to dry for a full 24 hours. If the cement is not fully dry, it may be flammable and explode when the potatoes are launched, creating a fire hazard.

• Electrical tape must be used to attach the spark generator the PVC conduit in Step 4. Duct tape is conductive and could create a fire hazard when the potatoes are launched.

• The potato launcher propels the spuds at a high speed when the trigger is pulled. The flying potatoes can seriously injure people or pets, so be certain the launcher is not pointing at any living thing when fired.

References

• YouTube: How to Make a Potato Launcher