Pneumatic battery rifle
This was my first ever cannon. It was designed to fire AA batteries at a
pressure of 12 bar (174psi)! It defiantly worked how I wanted it to and can easily fire
battery through a sheet of ply. I use an electric air compressor to get it pressurized
up to 12 bar.
This cannon was not based on any specific chamber to barrel ratio dimensions - I
simply used bits of pipe fittings that I found around my garage.
Materials used
All piping/plumbing components are made from 'quick-fit' pressure rated PVC -
12bar (174psi).
• Two 50mm Ø, 90°, bend
• 22mm Ø, 40mm long pipe
• 22mm Ø, 65mm long pipe
• 22mm Ø, 80mm long pipe
• 22mm Ø, 400mm long pipe
• 19mm Ø, 400mm long pipe with a 15mm inner Ø
• Two 22mm Ø, elbows
• 22mm Ø, stop end
• 22mm Ø, ball valve
• Bike (or car) tire valve
• Multi purpose adhesive
• Electric air compressor
Construction of the cannon
To make the chamber I simply connected a 90° bend to the 22mm Ø, 400mm long pipe.
The stop end will be connected later after the inlet valve has been added.
I then fixed the 22mm Ø, 40mm long pipe and the 22mm Ø, 80mm long pipe to the
ball valve (making sure that the ball valve was oriented correctly to allow easy
operation).
Then another 90 bend and 22mm Ø, 65mm long pipe were attached to
the shorter end of the valve construction. Refer to photo.
To stop the batteries from falling too far back down the barrel i applied a ring of multi purpose glue around one end of the 19mm Ø, 400mm long pipe. The barrel was then solvent welded into the open end of the ball valve
section, as shown in the photo.
To make the inlet pressure valve part i drilled a hole in the centre of the end
stop allowing a TIGHT fit of the bike tire valve (or car tire valve).
This end stop was then just connected to the open end of the chamber to complete the
rifle.
Here is a picture of the finished rifle:
Firing the cannon
This is just a small guideline to operating the cannon - to get best results you
will need to practice and develop you own methods of operation.
Note: ABS and all plastics become brittle and change pressure ratings in very cold conditions, and
therefore it can be potentially dangerous to operate the cannon in such conditions (i.e. don't operate during mid winter!)
• Attach an air compressor to the inlet valve and making sure ball valve is
closed.
• Pressurize the rifle and load an AA battery into the barrel.
• Sharply crew the access plug back onto the chamber tightly and connect an air
compressor or foot pump to the tire valve and pump to desired pressure.
• Aim well and sharply release the ball valve.