After making several small compressed air cannons I decided to make a Tennis Ball Mortar. This project can be a little bit expensive depending on where you buy you supplies. I would suggest going to a Home Depot or Lowe's because Ace is a little bit pricey.
Teachers! Did you use this instructable in your classroom?
Add a Teacher Note to share how you incorporated it into your lesson.
Step 1: Getting Ready
Items you will need:
5 ft 3 in of 2" PVC or ABS
3 ft of 3" PVC or ABS
3" of 2" PVC Scrap
1 PVC 2" Ball Valve
1 2" T Connector PVC or ABS
2 2" 90° Elbows PVC or ABS
2 2" PVC End Caps PVC or ABS
1 3"-2" Adapter PVC or ABS
PVC Glue and/or ABS Glue
Compressed Air Intake Valve/ Bicycle Valve
Drill bit that is the same size as your Intake Valve
Since some stores don't have 3" PVC you can buy ABS, but when you glue PVC to ABS you need to use PVC AND ABS GLUE on the same glue joint.
Step 2: Cutting
You will need to cut 6 different pieces from your 5 feet of 2" PVC.
Pieces you need to cut:
2 15" pieces of 2" PVC
2 11" pieces of 2" PVC
1 5" piece of 2" PVC
1 4" piece of 2" PVC
These are the only cuts you need to make for this project.
Step 3: Gluing
Look at the picture to see how to glue the mortar base together.
Make sure that you T connector is at a 45° angle.
(IMPORTANT) LEAVE ONE OF THE END CAPS OFF SO YOU CAN PUT YOUR AIR INTAKE VLAVE IN IT! AND DO NOT GLUE ANYTHING ABOVE TO BALL VALVE IF YOU WANT TO BARREL TO BE INTERCHANGEABLE!
Once done gluing, let the mortar base dry for 2 hours.
Step 4: Instaling the Air Intake Valve
THERE ARE TO WAYS TO COMPLETE THIS STEP!
*FULL METAL VALVE OPTION: Drill a hole in the 2" End Cap of PVC that you did not glue on to the mortar base. The hole should be just smaller than the diameter of the Air Intake Valve, then thread the valve into the end cap. Glue the End Cap on to the mortar base and let it dry for 2 hours I got a full metal Air Intake Valve because bicycle valves wear out and break over time. I got my Full Metal Intake Valve from amazon: Amflo 701-2 1/4 npt tank valve - Amazon.com I have used this valve on all of my projects and I is almost impossible to break.
* BIKE VALVE OPTION: If you don't want to buy a Full Metal Valve you can use a valve off of an old bike tire. To to so, cut out the valve with scissors with a little bit of rubber left over around the valve itself. Then drill a hole exactly the same size of the valve, then pushed the valve through the hole to make sure it fits. If it fits then take the valve back out, then put glue on the valve and put it back into the cap. Let it dry for 2 hours
Step 5: Barrel Assembly
(IMPORTANT) DO NOT GLUE ANYTHING ABOVE TO BALL VALVE IF YOU WANT TO BARREL TO BE INTERCHANGEABLE!
IF YOU WANT THE BARREL TO BE INTERCHANGEABLE: Just glue the 3" barrel to the 2"-3" Adapter then shove the 3" of 2" PVC Scrap into the 2"-3" Adapter. Then put the barrel on the on the ball valve, and let it all dry for 2 hours. Once it has dried you are done building your Tennis Ball Mortar.
IF YOU WANT A FIXED BARREL: Glue the 3 ft of 3" barrel to the 2"-3" adapter, and then glue the adapter to the 3" of 2" Scrap Pipe. Once that dries, glue the whole barrel into the Ball Valve. Let it all dry for 2 hours, once dry you are done building you Tennis Ball Mortar.
The barrel that I have just assembled below is the 3" barrel. If you want to use a 2" barrel then remove the 3" barrel and replace it with 3 ft. of 2" PVC.
Step 6: Firing You Tennis Ball Mortar
To pressurize your Tennis Ball Mortar use a bike pump or air compressor, and pump the pressure vessel to 40 psi. Listen around the base for any leaks. If you find a leak then cover it up with PVC glue or seal it with Epoxy. Once done checking for leaks pump the the Mortar up to 120 psi and get a Tennis Ball, load the barrel, and fire! The Tennis Ball shouldn't go that far because there is no wadding. To make wadding take an old T-Shirt and cut out a 8in diameter circle and wrap it around the Tennis Ball. Tie of the excess T-Shirt at one side of the tennis ball. If the tennis ball still is lose you can attach another layer of T-Shirt.
Step 7: Safety!!!
DO NOT SHOOT THIS MORTAR INDOORS!!!
DO NOT SHOOT THIS MORTAR AT CARS, WINDOWS, HOUSES, ANIMALS, PETS, OR OTHER PEOPLE!!!
IF SHOOTING DEADLY OR SHARP PROJECTILES OUT OF YOUR MORTAR MAKE SURE IT IS IN A SAFE PLACE WITH NO ONE DOWN RANGE OF THE MORTAR!!!
FOLLOW ALL STANDARD SHOOTING RANGE RULES AND REGULATIONS
I AM NOT LIABLE FOR ANY INJURES OR DAMAGE RELATED TO THIS MORTAR!!!
Participated in the
Weekend Projects Contest