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.

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.

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.