Index

This page is under construction, but should provide an alphabetical list of common spudding terms, as well as a note/definition about the term.

If you feel like it, start adding things.

B

Barrel - present on all cannons. If you don't know what one is, I suggest you find another hobby - or maybe click the link and read carefully.

BBMG - See BB machine gun.

BB Machine Gun - Pneumatic gun designed to fire airsoft pellets or metal BBs at high rates of fire.

Bottled Gas - See Gas Bottle

Butane - A common fuel for combustion spud guns.

C

Chamber - An element shared by all pressure based cannons, where either the pre-compressed air or flammable gas mixture is stored before firing.

Chronometer - 1. A device for measuring time. 2. A device for measuring the muzzle velocity of a gun. See also Chrony, muzzle velocity.

Chrony - A comercial device for measuring the muzzle velocity of a gun. Used for "real" guns, paintball guns, bows, and spud guns.

Combustion Cannon - A cannon that generates pressure by burning flammable gases.

Compressor - Motorised air pump.

Copper - Metal. Construction material.

D

DDT - Deflagration to Detonation Transistion. This very dangerous effect occurs when the flame front in a combustible gas mix exceeds the speed of sound in the gas - creating a super sonic shockwave and a very large pressure spike which may damage or destroy the chamber. It is very rare, and is only likely to occur in high mix Hybrid cannons.

Diaphragm valve - Related to Piston valve. Generally rarer, but often considered to open faster but have lower flow.

E

Epoxy - Very useful material. Often used for sealing leaks or during sprinkler valve modification, or some people have created very large parts of cannons from them.

G

Gas Bottle - A metal cylinder filled with pressurized gases.

H

Hybrid Cannon - A cannon that uses a pre-compressed flammable gas mixture. Very powerful, but requires experience to successfully and safely implement.

I

Ignition source - Used to start the combustion reaction in a combustion cannon

M

Mach - The speed of sound for a given set of environmental conditions. The speed of sound changes somewhat with temperature and the nature of the fluid involved. For dry air at 15C, one Mach is equivalent to 340.3 m/s (1,225 km/h, 761.2 mph)

Muzzle Knife - (Aka Spud Cutter.) The sharpening of the muzzle (business end) of a barrel so that it will automatically cut a spud to the proper size for the barrel. See also spud cutter.

P

Piston valve - A high power home-made valve which is generally considered to be second only to Burst disk valves in performance, but more practical to use. See also: Diaphragm valve

Pneumatic Cannon - A cannon that uses pre-compressed air for power.

Propane - A common fuel for combustion spud guns.

PVC - Most common spudgun construction material. Gets brittle in cold weather, and may shatter if dropped or abused. Quite cheap.

Q

QEV - Quick Exhaust Valve. Essentially a pre-made piston or diaphragm valve. These are quite hard to find, and typically moderately expensive.

S

Safety - More important than even the spudgun. If you don't have this, then you need it fast.

V

Valve - Essential to pneumatic cannons.