Overview of FS resized.jpg My latest creation. As the title suggests, I using a QEV and 3 position 2 way valve with a 300 psi input from a regulated HPA paintball tank. I have two different barrels, one for 3/8 inch (9.5 mm) steel shot and another for .30 caliber steel shot. The 3/8 inch barrel is ...

I bought the Ceda S and just shot it across the living room. Hoooly crap! I knew what to expect in terms of FPS from reviews online, but I was still totally surprised at how fast it shoots. My kid's nerf blasters just sort of float the dart across the room, and this thing rockets them in a straight ...

I haven't seen a lot of side-by-side comparisons of different potato cannon designs. Since I have a bunch lying around, I figured I'd do some "scientific" (ha!) measurements of power, accuracy, etc, and see if I could narrow down which ones are the best. Now, I don't have anything super advanced her...

Tap an 1/8" NPT and get an ASA adapter that will thread into it from www.palmerspursuit.com then get a regular paintball style with ASA threads.

My new self-made short gun. It is a hybrid pistol, with a built-in air pump, that operates with 8x and five strokes only. It shoots common pellets, .22, and the firing barrel is 12 micro-ridged, 200mm long. My friend's chrono gave about 650 fps on 4.5 ml of butane. It weighs about 900 grams, and ret...

With bolt-on system for loading ammunition, I finished it yesterday

I got a good price for a silencer that is just right for the barrel thread. The gun was literally silent! , in good time.

New site looks great! Come a long ways since the SpudTech era!! At any rate, playing around with a piston build for the first time in a decade. I've used the basic air compressor blow gun plenty of times in the past, but they just feel like they are made of $1 worth of chinese steel (odd, right?). I...

Otherwise known as a pellet/bullet shooting crossbow. I built this thing to see: A) how accurate are they? B) how fast do they shoot? What I've learnt is that these things are super finnicky! I've shot paintballs with insane ball-on-ball accuracy at 25 yards, then tweaked the string/pouch and had pa...

I made a more detailed drawing of this type of trigger valve that I am testing. In fact, it is necessary to contain the kinetic energy of the ball, when it has left the main retention that blocks the combustion chamber. The problem that appears is that the ball tends to bounce and obstruct the gas o...

What I should do is build a piston valve like the one you drew and compare with the other, to see directly how they behave. I have compared it to the rupture disc system that I have, that which I built at the beginning, with aluminum foil discs, and I am working on that. I haven't noticed much of a ...

There's a lot of mass in a 3" piston, and PVC is fragile. The break at the barrel end was clean and exactly at the stress riser where the reducer meets the valve body, looks like shock fracture rather than pressure rupture. Lesson to learn - don't do that. At 2:00 or so, he says "That's not funny. I...

I like the system, I did not know it. I have a kind of "grenade launcher" that works with a rupture disc, but it is not exactly like the drawing. The projectile is simply housed in the firing barrel. It is an ancient weapon that I built, that I adapted for this purpose. The "cartridge" that houses t...

This is. I know it is not the same because the weapon has a firing barrel, but it has something to do with it, I think.

To get myself to build some stuff again I decided to slap a cannon together in my lunch break, with all designing and calculating done on the fly. I noticed that the projects where I spend a lot of time designing and preparing often don't actually end up being built at all.. Basically this is a quic...