Workin' on a coaxial sleeper build

[Moonbogg]

Looks like an average cannon until you see the inside. I used the chamber volume efficiently for valve design to maximize flow with no restriction; 1 5/8" port with radial chamber vents that exceed the port surface area. Like my last design, there is no pilot venting per shot. The barrel will easily unlock by twisting a quarter turn and you take it out (if you want) to load spuds or mini 2 1/4" diameter soda cans, or mini tennis balls.
Can use a ram rod with a plastic piston on the end to pump and pull through the barrel to exhaust and get fresh air to the chamber to reduce air pumping with the bike pump for each shot. This is my simplest, cleanest, lightest, most effective design yet. A solid 4X coaxial design. Weakest link is the chamber wall (1/8") and should blow around 2500psi. The threads are ridiculous and are basically indestructible, so the chamber walls will blow before anything else gives out, and expected max, closed chamber pressure is around 400-500 ish PSI, so that's good.

[mobile chernobyl]

Very cool design and use case. What sort of lathe/mill equipment will you use for the custom parts? Will the main chamber be sch10 3-4" material?

[Moonbogg]

I don't have a lathe, so I'll have to pay a shop, and it will cost a fortune. Basically like buying a car probably. But, this design is far simpler and easier to machine than my last ones. Mostly turning and that's it. My last 2 were very expensive and they did me a favor by letting me exchange my labor for theirs, but I'm not expecting that. I haven't chosen the stock material yet, but it will likely be heavy wall seamless tube for the chamber, and tubing for the barrel that is close to what I need so we can just clean up the OD and hone the ID a little. Everything is 6061-T6 except the piston housing, which will be 7075-T6 to keep it lighter. Here's a revised design. I got the weight down almost 2 lbs with this. The pilot housing is the only threaded part that clamps everything else inside against the chamber shoulder. No pilot venting needed. Barrel ID is specifically to fit the mini soda cans, the 7.5oz ones.

[mrfoo]

You need to make friends with a local home shop machinist. I'd happily do stuff for you, but flying over here would cost an arm and a leg. Plus, flying back with a "weapon" might cause problems.

[Moonbogg]

Thanks mrfoo. That would be great. I think you should just buy the house next to me and move in just so I can make a cannon. And then, maybe Chernobyl can buy the house on the other side and we can just pump out cannons all day. Seriously, all I want to do is work on my cannon right now. I want time to stop and I just want aluminum, machines, and a quiet world so I can just make my cannon. My whole mind is a potato gun right now.

I also think it's funny some people consider spudguns weapons. If I had no choice but to use a cannon as a weapon, I'd definitely take the barrel out and start swinging it to protect myself, it would be far more effective. Can you imagine? OK, someone breaks in, they approach me, and I say politely, "Oh, well, yes. Can you wait for me to find my propane, bike pump, charge my stun gun, charge my pilot, fuel the cannon, grab a soda can, load it up, and then hold still while I shoot you?"

[Moonbogg]

I'm trying to simplify this thing as much as possible; less parts, less machining, less weight, less cost, while having the chamber volume I want. I won't be selling it or anything, but I imagine if a spudgun like this was sold on the market, what would it be like? It would be clean and simple to save cost and work well, so that's what I'm going for.