Maximizing Decibels, and a Few Other Questions...
Posted: Wed Jul 06, 2011 3:11 pm
Hi. I apologize in advance for the length, but I want to make sure I provide enough information to answer the questions.
We are in the final chassis design stages of a paintball vehicle loosely-based upon the AML-90 armored car, and we're starting design work for the vehicle's various systems (electrical, armament, etc.). The main gun on the vehicle will fire nerf footballs, the "standard" heavy weapon round in scenario paintball. Scenario regulations restrict velocity to somewhere between 240-300 fps, depending upon the event's insurance.
After some discussion, the team has settled upon a steel pneumatic QDV gun, probably 3- or 4-inches of bore diameter, and 8- to 10-feet in barrel length. The pneumatic QDV will allow us to vary pressures, keeping velocities low for paintball, and allowing pressures up to 250 psi for off-the-field entertainment. We have not yet decided upon the chamber size or configuration.
We have a few questions for the experts:
1 - How can we maximize the report of our gun? We want as big of a gut-shaking boom as we can create - literally, the biggest bang for a given pressure/air volume.
2 - We are thinking the chamber will be a 60# propane cylinder (12"X44", 64.8L before subtracting barrel volume), configured concentrically around the barrel as with technician2002's Marshmallow Gun, or an oxygen cylinder (9"X55", 49L) in an over-under configuration. The over-under configuration will make design of the quick-loading breech mechanism easier, but will the angle-induced turbulence and increased resistance from increased valve-to-projectile distance limit our flow noticeably? (We'd love to see maximum effect on random household items using concrete-filled projectiles and 250 psi!)
We are in the final chassis design stages of a paintball vehicle loosely-based upon the AML-90 armored car, and we're starting design work for the vehicle's various systems (electrical, armament, etc.). The main gun on the vehicle will fire nerf footballs, the "standard" heavy weapon round in scenario paintball. Scenario regulations restrict velocity to somewhere between 240-300 fps, depending upon the event's insurance.
After some discussion, the team has settled upon a steel pneumatic QDV gun, probably 3- or 4-inches of bore diameter, and 8- to 10-feet in barrel length. The pneumatic QDV will allow us to vary pressures, keeping velocities low for paintball, and allowing pressures up to 250 psi for off-the-field entertainment. We have not yet decided upon the chamber size or configuration.
We have a few questions for the experts:
1 - How can we maximize the report of our gun? We want as big of a gut-shaking boom as we can create - literally, the biggest bang for a given pressure/air volume.
2 - We are thinking the chamber will be a 60# propane cylinder (12"X44", 64.8L before subtracting barrel volume), configured concentrically around the barrel as with technician2002's Marshmallow Gun, or an oxygen cylinder (9"X55", 49L) in an over-under configuration. The over-under configuration will make design of the quick-loading breech mechanism easier, but will the angle-induced turbulence and increased resistance from increased valve-to-projectile distance limit our flow noticeably? (We'd love to see maximum effect on random household items using concrete-filled projectiles and 250 psi!)