Launcher configuration
Chamber-Barrel position
The possibilities are limmetless, but these are the most common ways to position the chamber and barrel:
- "linear"
The barrel is directly infront of, and pointing in the same direction as, the chamber. It's slightly cheaper than the over/under configuration, but only by the cost of 2 90* elbows.
- "over/under"
The barrel is turned 180* (using 2 90* elbows, typicaly) so that it points in the oposite direction of the chamber, and is directly over it. This makes the total launcher length shorter, although the 90* bends will slightly reduce flow. Barrel suports are recomended to re-enforce the launcher, and keep the barrel steady.
- "co-axial"
The barrel is placed inside the chamber. This is made possible by modding the reducing bushing, allowing the pipe to be glued in it backwards. This makes a rather nice looking launcher, and is most commonly used when constructing a diaphram or piston valve, which requires the part near the valve to be co-axial anyway. It can be a pain to vent and mix the combustion products/fuel if you make a co-axial combustion.
- "multiple tanks and Ts"
Like the setup used on the megah-launcher. However, the multiple bends results in lower flow. The GGDT typicaly doesn't show much improvment from the increased chamber volume.
Ammo delivery
The basic option. Projectile loads from the front, and reload time is quite slow.
- union loading
A step up. Alows you to load the projectile from the breach, but requires alinment and twisting afterwards. Also alows you to make burst-disk shots.
Alows you to load a projectile from the breach (end of gun towards user). Mechanism and loading time varies by construction technique.
A tube holds the ammo, about around 1/2 dozen balls. Appon firing, the balls are sucked one-by-one into the airflow, resulting in a tight grouping of balls fired a few dozen miliseconds apart. Suitable for large-caliper weaponry (has been tested with as large as tennis balls) Named after the late Bill Vogt, who came up with the desighn.
