Development of a breech design
Posted: Sat Apr 07, 2007 2:46 am
Hi there, I'm a long-time watcher, first time poster -- I just couldn't resist getting back in the fray of spudguns after being inactive for over 5 years.
Anyway, I've looked through the pneumatic cannon database and saw pretty much every entry made. Most of the guns which aren't muzzle-loading seem to be loaded via a bolt-action design, with some exceptions.
The majority of my larger cannons are over-under designs, for the sake of space. If any of you remember Joel's Mega-Launcher, he had a threaded end-cap on a cross, opposite of the barrel, where ammo's loaded. Air comes in the two sides perpendicular to the barrel/cap.
Instead of screwing the cap on, I wanted to design a breech that somewhat emulates the breech of real artillery; with a hinged plug that'd seal against the very rear of the breech for quick loading and firing. Although I feel this could allow larger cannons to be fired more quickly, it's more of a proof of concept than anything since many larger cannons take a while to refill the air chambers. Think of those air-tight jars with the hinged lid and either a nylon or rubber o-ring to make the seal.
So, I wanted to adopt this concept. Since my cannon testbed is a typical over/under with no barrel at the moment (with a 2" QEV that bends at a 90 degere angle, and is attached directly to my tank), I plan on attaching my 3" barrel piece directly to a 3" Tee, with the 90 degree connection going to the valve (with a 3" to 2" bushing somewhere in there). The unused end would of course be my breech. Again, this is just a proof of concept and for my own development as I start using larger-diameter barrels. Breech-loading bean cans in this manner could be incredibly convienent!
Has anyone tried this with any success?
Anyway, I've looked through the pneumatic cannon database and saw pretty much every entry made. Most of the guns which aren't muzzle-loading seem to be loaded via a bolt-action design, with some exceptions.
The majority of my larger cannons are over-under designs, for the sake of space. If any of you remember Joel's Mega-Launcher, he had a threaded end-cap on a cross, opposite of the barrel, where ammo's loaded. Air comes in the two sides perpendicular to the barrel/cap.
Instead of screwing the cap on, I wanted to design a breech that somewhat emulates the breech of real artillery; with a hinged plug that'd seal against the very rear of the breech for quick loading and firing. Although I feel this could allow larger cannons to be fired more quickly, it's more of a proof of concept than anything since many larger cannons take a while to refill the air chambers. Think of those air-tight jars with the hinged lid and either a nylon or rubber o-ring to make the seal.
So, I wanted to adopt this concept. Since my cannon testbed is a typical over/under with no barrel at the moment (with a 2" QEV that bends at a 90 degere angle, and is attached directly to my tank), I plan on attaching my 3" barrel piece directly to a 3" Tee, with the 90 degree connection going to the valve (with a 3" to 2" bushing somewhere in there). The unused end would of course be my breech. Again, this is just a proof of concept and for my own development as I start using larger-diameter barrels. Breech-loading bean cans in this manner could be incredibly convienent!
Has anyone tried this with any success?