At first glance, that looks an awful lot like a remote-accumulator Arizona cannon. I'm looking forward to a breakdown of the guts. Tell us what makes this thing tick Awful lot of shavings there, too. Time to break out the shop-vac?
I guess it would look like the accumulator, huh? Never thought of it like that... Nope, that's the actual reload mechanism. I will buy more gas tonight & finish my tests.
... Actually, a remote-accumulator Arizona gun is one where the accumulator and firing mechanism is separated from the breech, magazine, and barrel by a length of large-diameter hose so it can fit in tighter spaces... That reminds me, I need to add more to my guns article. Good thing spring break is only a few days away. until then, finals, urk!
It looks a lot like the drawings I've been doing for a sealed-breech cannon, only different LOL My ugly-@$$ cannon had an external bolt return spring, tho. Yours looks much spiffier. Did that cylinder come threaded, or did you have to do it? ps- that's power! watch your eyes, man!
>Did that cylinder come threaded, or did you have to do it? hehe... I have machined the whole thing from raw materials. The only thing I didn't fabricate is the 1/8NPT hose adaptor. My local hardware store had the perfect (internal) piston return spring for me; so I installed it last night. The system seems (reasonably) reliable. But I don't think I'll really know until I'm out on a pond. Unfortunatly they didn't have the right size o-ring. So power levels aren't too high yet. Still with the 1/8 hose, it is pretty powerful. >remote-accumulator That is similar to what is happening here... (So I guess there is another hybrid that should be attached to the design description?) I want to package everything that isn't compatible with both BB & 1/4 Ball bearing into one removable part. I also wanted to keep the rotational mass as light as possible, for fast/responsive rotation. The result is the cannon you see above. The main difference between this cannon & an arizona is the Kat Cannon uses a piston to prevent venturi effect. The effect is this cannon can be a lot more efficient as far as gas usage is concerned.... It simply doesn't need as much air to fire. The whole cannon weighs almost nothing, so 3 will be very light & easy to rotate by one overdrived servo. It is also a requirement to be able to swap in a 1/4" BB cannon for Big Gun battles. I think it is pretty obvious that all i need to do is unscrew the bottom 1/8NPT hose adaptors & remove the assembly from the boat... Another requirement is the Kat Cannon is easy to repair in the field... So if Carl decides to shoot a ding in my barrel, I will more than likely be able to repair it IN THE FIELD. (the solid removable barrel design has let me create a special repair tool for removing dings... Thanks to my father's instrument repair concepts) As you can tell, I'm very interested in talking your ear off about it. But, I would feel pretty stupid if I talked my ass off about it & then it proved to be a bad design. I think the concepts are there & are sound... but I've never designed my own weapon before.
Hey, talk our ears off. Let us know more about it. That way, if it proves to be a bad design we all know why, and what to do better next time. Personally, I'd love to know what the insides look like so I can see if there's anything I can incorporate into other cannon designs. I do have two concerns. First, it looks pretty tall to be put in a 1/144 scale ship. I trust it will get shorter as you get better at bending barrels? Second, you mentioned 1/8" airline as the feed. That stuff's usually pretty stiff, so I'm a bit concerned how well it will rotate.
I think it must be a camera aspect thing... It does look a little tall. The cannon in reality isn't really that tall. It should fit pretty well into the ship as is. However, if needed; there is a bunch of extra tube I can lop off the barrel or (if absolutely needed) I can shorten the reload by quite a bit. I've heard this before... but I don't know if perhaps I have different stock or what, but it doesn't feel that bad to me. I think it will work A-OK just as is.
Are you using clippard 1/8" standard airline? From what I see it looks different, but I'm not certain. As for camera perspective, I was initially thinking it was a 1/4" cannon. That's for .177" shot, right? If so, have you started on the 1/4" version yet?
Clippard, yes... 1/8", yes... "Standard"? I think so... This version is for BB, yes. I've decided the priority for my Iowa is fast gun competition, so I need BB guns first. I have started on the 1/4" version, yes. I created a MkI 1/4" version. I was similar in impact power to the BB gun, and suffered the same issues as the BB MkI cannon. I decided it was a good "proof of concept", but it was uneconomical to create 2 versions of each cannon until I had perfected 1 yet. I have uploaded more details on the internal workings of the cannon... This is a picture of the Kat Cannon assembly... From Left to Right: Hose Bottom, Nut, Piston selector w/ spring, gun casing w/ magazine lead, O-Ring, Compression fitting, Compression nut, barrel... Underneath a Clippard Maximatic valve. This a picture of the piston selector itself; notice it has a hole going right though the center. This increases airflow. The bottom of the selector is "cupped", which catches the air & provides enough force to overpower the spring. Notice the small spring that is used to keep the gun from jamming. It is only long enough to push the piston out of the way of the "next BB".
I also just did a little more testing of the Cannons... After calibration: The cannon didn't misfire at all, however I don't know "out of how many"... I just shot and shot and shot until I was satisfied. The penetration was consistently around 1.5" blue styrofoam, @ 12"... Now that I have a o-ring to compress, perhaps I can increase that... I am fairly happy with that though. The it has very repeatable accuracy @12". It only typically had a dispersion of about 1/4" in any direction... I have no idea how much of that was my hand. I would be willing to bet if I clamped it down it would go through the same hole +/- 1/4" everytime. And now I have 300 or so BBs floating around my den & probably in the fish tank...
