Search found 2503 matches
- Fri Feb 01, 2008 9:07 pm
- Forum: BB, Airsoft, and Pellet Guns
- Topic: Finally! hammer valve time!
- Replies: 7
- Views: 1856
- Wed Jan 30, 2008 5:15 pm
- Forum: Pneumatic Cannons
- Topic: HEAL 320psi 20mm copper cannon (now with damage videos)
- Replies: 163
- Views: 40296
- Wed Jan 30, 2008 12:17 pm
- Forum: General How-To & Discussion
- Topic: Do you worry what your cannon looks like?
- Replies: 27
- Views: 4929
- Sun Jan 27, 2008 9:21 am
- Forum: Pneumatic Cannons
- Topic: C/B Ratio and PSI questions
- Replies: 10
- Views: 1707
- Fri Jan 25, 2008 6:41 pm
- Forum: BB, Airsoft, and Pellet Guns
- Topic: Slide valve automatic airgun
- Replies: 20
- Views: 11591
Hey, sorry for causing confusion. :oops: What I meant by a stepped bolt was that it changed diameter abruptly, instead of tapering. My thinking was that it would take up more volume and reduce dead space. I should also have written tilting "face" valve. The valve would still be 90 degrees to the bol...
- Thu Jan 24, 2008 2:57 pm
- Forum: BB, Airsoft, and Pellet Guns
- Topic: Slide valve automatic airgun
- Replies: 20
- Views: 11591
Hmm... Just a suggestion, but what about doing away with the taper all together, and using a tilting valve? If I'm thinking this through correctly, the valve would open/close faster. With a stepped bolt, it should also cycle on less gas volume. Have to limit bolt travel of course. Other than that it...
- Tue Jan 22, 2008 5:28 pm
- Forum: Pneumatic Cannons
- Topic: C/B ratios and diminishing returns
- Replies: 17
- Views: 3008
I noticed the same thing. My chamber started out being 1.51"idx18" long. Running numbers, this has shrunk to 1.51"id by 10" long (with a 1" barrel running through!) That's down to about 10 cu.in. Performance loss was noticeable but acceptable (at least according to ggdt). I didn't run numbers at low...
- Tue Jan 22, 2008 1:46 am
- Forum: Pneumatic Cannons
- Topic: the HELIX naval cannon.UPDATE:more damage pics!
- Replies: 15
- Views: 5093
- Tue Jan 22, 2008 1:35 am
- Forum: General How-To & Discussion
- Topic: what type of cannon do you like?
- Replies: 48
- Views: 7938
Every one that I look at has something that I like. The ideas of others are often the fuel for creativity, adding or changing something to make it unique. The big launchers have crushing power, the smaller ones are perhaps more usable and precise. At the moment, I have to side with smaller, and port...
- Mon Jan 21, 2008 12:20 am
- Forum: Pneumatic Cannons
- Topic: High pressure co-axial build log- updated 11/14/08
- Replies: 112
- Views: 40686
High pressure co-axial build log- updated 11/14/08
All metal co-axial design. Piston to be piloted by a hammer valve. "Bullpup" configuration to keep it short. All tubing is 1026 DOM (Drawn On Mandrel) All internals are 1045 annealed for machining Barrel 36" 1"od. x .120" wall = .760" bore Chamber 1.51"id.x1"(barrel od.)x10" (.120" wall) about 10 cu...
- Sun Jan 20, 2008 11:40 pm
- Forum: Pneumatic Cannons
- Topic: My first piston cannon. With damage vid.
- Replies: 5
- Views: 3423
Hey, Thanks! Psycix - I shoot at 90 psi (I fill with a regulator). It is currently -23 C here, this means indoor testing and non penetrating types of ammo. (the boss would be PISSED if I shot a hole in the wall) :shock: I'll see about a vid in the next couple days. Elite - A golf ball barrel might b...
- Sun Jan 20, 2008 5:49 pm
- Forum: Pneumatic Cannons
- Topic: 2.4kpsi helium powered BB gun - build log
- Replies: 57
- Views: 10658
DYI, have you tried annealing the steel? I'm working with 1045 (medium carbon steel), and have to anneal each piece before machining on my tinker-toy of a lathe. Or you could try something like 1117 which is supposed to be free machining. You might also consider sealing your end with a quad-ring and...
- Sun Jan 20, 2008 5:25 pm
- Forum: Pneumatic Cannons
- Topic: My first piston cannon. With damage vid.
- Replies: 5
- Views: 3423
My first piston cannon. With damage vid.
Finished this a couple weeks ago. It works WAY better than I expected it to. Thanks for providing such a complete source of information all in one place. Specs, All pipe is 1 1/4" sch 40 pvc with a pressure rating of 370psi All fittings are sch 40 pvc pressure rated (to what?) barrel 36" chamber 48"...