Are you looking for a new way to pick on your siblings or friends? Are you looking for a fun new “toy” to build? If so, then follow these simple instructions to assemble your very own tennis ball gun!
The assembly of this gun takes approximately half an hour, and requires materials that can be attained at most supermarkets. The total cost of materials can vary, as can the materials, but can range anywhere from 20 dollars on up depending on how durable you would like to make the gun. The four main components of the gun will be a chamber, a barrel, fuel, and an ignition.
No previous experience is required, however, the assembly requires the use of sharp objects and flammable materials, so adult supervision is advised. The gun is best operated outside where there is less risk of breaking or burning materials.
Step 1: Materials
• Slender cylindrical tube (Penn 3 pack tennis ball container)
• Wide cylindrical container (Penn 12 pack racquetball container)
• Exacto Knife
• Hot glue gun with one stick of glue
• Two strips of two inch long electrical tape
• Three feet of duct tape
• Piezo Igniter
• Fuel spray (Axe body spray)
Note: The wider cylindrical container that will be used as the chamber needs to have a twist on lid and be approximately twice the diameter of the slender tube acting as the barrel. To increase the durability of the gun, the materials of the two containers should be a hard plastic such as PVC pipe. The type of fuel spray used has negligible effect as long as it is flammable.
Step 2: Start Assembly
Remove the lid to the tennis ball container; remove the balls; using the Exacto knife, cut the bottom ridges off of the tennis ball container to make the cylinder flat and open at both ends.
Using the Exacto knife, cut a circle into the center of the tennis ball container lid of approximately half of its diameter; dispose of the inner circle; place lid back on tennis ball container.
Warning: Improper use of the Exacto knife may result in injury.
Twist off the lid from the wide container (racquetball container) and set it flat on the table; center the tennis ball container on the racquetball container lid, and trace the outline with a Sharpie; cut along the trace with the Exacto knife and dispose of the inner circle.
Insert the tennis ball container through the hole made into the twist off lid. The end of the tennis ball container with the lid should enter at the top of the twist off lid and penetrate about an inch.
Plug in the hot glue gun; wait two minutes of it to warm up; place the stick of glue into the hot glue gun; spread the hot glue evenly across both sides of the twist off lid where the two containers meet. Make sure glue enters all the crevices so the containers are sealed tightly together and no heat can escape when the combustion occurs.
Warning: Glue and gun are hot. Avoid contact with skin.
Duct tape the crease where the two containers meet on the top side of the twist off lid. This is an extra precaution to keep the containers from wiggling and prevent heat from escaping.
Remove the Piezo igniter from its packaging; assemble using the instructions provided in the packaging; cut the end of both wires of the Piezo igniter so they are about one foot long.
Using the Exacto knife, poke a small hole into the side of the racquetball container large enough for both igniter wires to fit through snuggly.
Feed the igniter wires about three inches through the hole in the side of the container; using the hot glue gun again, spread glue across the outside of the hole with the wires through it to prevent the wires from moving.
Note: You are now done using the hot glue gun, so unplug it and place it out of the way.
Place one strip of electrical tape across the wires on both sides of the hole in order to keep the igniter wires immobilized.
Note: The two ends of the wires should be positioned so they are approximately two centimeters apart. If they are touching or too far apart, no spark can occur. Adjust if needed.
Step 12: Operating the Gun
Place the tennis ball inside the top of the barrel. The tennis ball should cover the hole cut into the tennis ball container lid.
Spray igniter fuel (Axe) into the racquetball container for about two seconds; immediately, seal the container by twisting on its lid tightly.
Note: If too much fuel is supplied, not enough oxygen will be present to carry out the reaction. Conversely, if not enough fuel is supplied, the reaction will be very weak and the ball will not travel far.
Aim barrel at target and immediately push down on the ignition button. Combustion will occur within the chamber and tennis ball will be fired out of the barrel.
Warning: If the gun catches on fire, remove yourself from danger and put out the fire.
Warning: Do not replace tennis balls with heavier objects, as it may cause damage or injury to the object being hit.
Step 14: Conclusion
Your tennis ball gun is now complete and has been tested. To fire the gun again simply repeat the previous two steps.
Many materials can be changed to suit your preference or budget. Changes in barrel and chamber size may have an impact on the distance the ball is shot, as will the amount of spray being supplied as fuel. Adjust the parameters to get your desired results.