Search found 193 matches

by Skywalker
Thu May 13, 2021 6:57 pm
Forum: General How-To & Discussion
Topic: "In the world of spuds today"
Replies: 2448
Views: 219695

Re: "In the world of spuds today"

https://media-exp1.licdn.com/dms/image/C4D22AQE-OLrsX-uJUA/feedshare-shrink_800/0/1620891745542?e=1623888000&v=beta&t=Kbml65sjTyKUzWdow98xZH9aqoBRdawD3QQfYGoqHS8 "22 metre £1.1 million hyper-velocity gas gun. 100 g projectile, which can reach a maximum velocity of 6.5 km/s using 3 kg of gunpowder. ...
by Skywalker
Fri Jan 01, 2021 5:10 pm
Forum: Hybrid Cannons
Topic: Single-pump hybrid concept
Replies: 6
Views: 1017

Re: Single-pump hybrid concept

No, I don't have plans to build anything like this soon -- I'm just thinking about how I would do it. I live in a small apartment in the suburbs. I have neither a place to shoot nor to do metal work. I made a small bolt-action cartridge hybrid once upon a time, though. My hope at the time was to be ...
by Skywalker
Fri Jan 01, 2021 3:02 pm
Forum: Hybrid Cannons
Topic: Single-pump hybrid concept
Replies: 6
Views: 1017

Re: Single-pump hybrid concept

Thanks for chiming in! > What I suggest is trying to keep everything as simple as possible. Have you seen your own diagrams?! :-P Seriously though, I want the operation to be simple for the user, even if it complicates the construction a bit. I got spoiled plinking with my brother's 22 rifle & 9mm p...
by Skywalker
Fri Jan 01, 2021 2:45 am
Forum: Hybrid Cannons
Topic: Single-pump hybrid concept
Replies: 6
Views: 1017

Re: Single-pump hybrid concept

A few more thoughts: I looks like Hector's little pistol has 16mL chamber, or ~1 cubic inch. I feel a bit silly for planning a rifle around a chamber with half that volume. So, I eked out a bit more performance by extending the lever arm to 24," the attachment point to 6.5," and increasing the cylin...
by Skywalker
Thu Dec 31, 2020 7:04 pm
Forum: Hybrid Cannons
Topic: Single-pump hybrid concept
Replies: 6
Views: 1017

Single-pump hybrid concept

I like @hectmarr 's work on these autonomous hybrids. I'm thinking about a design for a single-pump, high-mix hybrid. It seems to me that going for multiple pumps is a waste, since the resistance of the first few strokes is low, so one's arm is getting a lot of exercise just going back and forth. [a...
by Skywalker
Thu Dec 31, 2020 2:14 pm
Forum: BB, Airsoft, and Pellet Guns
Topic: Shock absorber spring rifle?
Replies: 3
Views: 1777

Re: Shock absorber spring rifle?

I like the idea of heating the air by compression in order to get around the sound barrier. That's kinda where I was going with it. I was also thinking that the energy efficiency would be higher than a pneumatic with a similar muzzle velocity. I think spring guns can get up to around 30% or so.
by Skywalker
Mon Sep 07, 2020 12:11 am
Forum: Pneumatic Cannons
Topic: Supersonic baseball cannon on 'Smarter Every Day'
Replies: 2
Views: 1183

Supersonic baseball cannon on 'Smarter Every Day'

They built a balanced piston valve. Very heavy-duty steel, they've run it as high as 500psi. The barrel is evacuated before the shot. There's a nice shadowgraph image of the shock wave from the supersonic baseball. Discussion of the concept: https://youtu.be/E60G3ba4TUA?t=296 The shock waves start h...
by Skywalker
Sun Mar 22, 2020 12:25 pm
Forum: BB, Airsoft, and Pellet Guns
Topic: Shock absorber spring rifle?
Replies: 3
Views: 1777

Shock absorber spring rifle?

I bet a motorcycle or automotive shock absorber could be turned into a wicked spring rifle... might be on the dangerous side tho! Inspired by seeing one in the dumpster the other day.
by Skywalker
Sat Nov 02, 2019 10:57 am
Forum: Hybrid Cannons
Topic: Two-stage hybrid
Replies: 32
Views: 9322

Re: Two-stage hybrid

Interesting concept, me gusta! The trouble with conventional dieseling spring-guns is the variability of the ignition timing due to fuel mix, which can damage the piston and cause unstable muzzle velocity. Having the ignition occur at a fixed compression could help solve those problems. Metering the...
by Skywalker
Tue Apr 09, 2019 11:19 pm
Forum: Hybrid Cannons
Topic: Cooking up a little something...
Replies: 79
Views: 20037

Re: Cooking up a little something...

Damn, that's impressive looking even in CAD. I'm looking forward to the IRL version! Go big or go home, eh? :D
by Skywalker
Tue Apr 09, 2019 8:00 pm
Forum: Hybrid Cannons
Topic: Autonomous hybrid caliber .25 Prototype 3
Replies: 16
Views: 5313

Re: Autonomous hybrid caliber .25 Prototype 3

Very nice work! I would copy this design if I had the space & time to work on airguns again.

What style of valve is used? Any progress on the pump?
Edit: Ok, I have read the latest thread now and I understand the gun. Very cool.
by Skywalker
Tue Apr 09, 2019 8:43 am
Forum: Pneumatic Cannons
Topic: Balanced Hammer Valves
Replies: 19
Views: 5030

Re: Balanced Hammer Valves

I'd been ignoring friction for the most part. Friction isn't an entirely bad thing for this design, though: the valve-pusher cylinder should *not* travel with the poppet valve -- it needs to stay behind so that the poppet unseats. The whole train of (hammer --> breach slide --> valve pusher --> popp...
by Skywalker
Mon Apr 08, 2019 10:06 pm
Forum: Pneumatic Cannons
Topic: Supersonic peashooter
Replies: 5
Views: 1825

Re: Supersonic peashooter

Edit: Anatine, I didn't read your response before posting! You scooped me, haha! :oops: Hydrogen would definitely help, although it would be a waste to use it this way without igniting it. :D Dieseling the air gun would definitely help get the energy up -- I've been thinking about how to construct a...
by Skywalker
Mon Apr 08, 2019 8:47 pm
Forum: Pneumatic Cannons
Topic: Balanced Hammer Valves
Replies: 19
Views: 5030

Re: Balanced Hammer Valves

Interesting -- so it's a dump valve, though. Looks to me like the unbalanced force is going to blast it open and keep it that way, just like the QDV. I sketched up an idea for a balanced version of the AirForce Condor. The basic idea is to transfer the hammer strike through a movable cylinder to the...
by Skywalker
Sun Apr 07, 2019 1:02 pm
Forum: Pneumatic Cannons
Topic: Balanced Hammer Valves
Replies: 19
Views: 5030

Re: Balanced Hammer Valves

These are cool, but can they be re-arranged to look more like the typical piston gun, where the porting is full-bore straight into the breach? I guess you'd need an awkward hammer that pulls, rather than pushes, the stem.