SpudFiles

A 3/2 lever valve connected Normally Open as I fill through the valve.

When you want to sell your spudgun but Facebook is anti-gun, one has to get creative

And they are illegal in Florida

https://en.wikipedia.org/wiki/Spud_gun_ ... ted_States

I spit out an olive pit with your mouth and I'm breaking the law ... state bureaucracy

I just launch them on my farm. Loads of space and it echoes nicely. I ran into a problem on the way though, A FLIPPING CHECK-STOP! Cops didn’t notice the tater guns or didn’t care fortunately.

Anybody know or have information on airsoft operating pressures? Internal barrel pressure at time of firing I mean. Can't seem to find any figures on this, maybe secret. I would be interested in spring vs electric vs Co2 vs Hpa ?

farcticox1 wrote:Anybody know or have information on airsoft operating pressures? Internal barrel pressure at time of firing I mean.

Not really a secret.

For all intents and purposes, spring and electric guns run on the same principle in terms of firing, the only difference is that in the latter case it's an electric motor that cocks the piston through a gearbox instead of having it manually cocked.

flash animation elucidating the complex nature of piston airgun dynamics, determining the barrel pressure curve is a more challenging undertaking.

HPA replicas would be the easiest to model, they are usually run at 70-120 psi from the regulator so here is a GGDT model of a typical setup:



As you can see peak barrel pressure does not exceed 30 psi.

Using CO2 that has a much higher chamber pressure, this is what it would look like in an airsoft pistol:



To achieve a similar velocity with a short barrel, barrel pressure is higher than the HPA example however maximum barrel pressure is just under 60 psi even though we're at 850 psi at the chamber.

Read somewhere around here spring airsoft guns can reach 300 psi in the chamber, might be legit since it's such a low volume compared to HPA and CO2

wyz2285 wrote:a low volume compared to HPA and CO2

There's also the heat factor to consider given the sudden compression.

True, it is pretty warm at the nozzle. Once tested a M150 gearbox it was so loud I thought it dieseled turns out just hard cylinder head and piston.
Any guess on the peak pressure? I tried to measure it with a gauge but the recorded pressure was too low probably duo to leaks and dead volume between the nozzle and gauge.

I think there is other stuff going on that makes it hard to measure peak pressure. There might have been part of a thread here about it. Pressure gauges need time to indicate, and moving pistons create pressure spikes that last for very short times. I think to measure momentary pressure there are strain gauges etc.

ITWOST I learned there is no such thing as potato cannons on the internet these days according to this "well informed" Vice reporter..https://www.google.com/url?sa=i&source= ... 5550954155

It puts the power of death in your hands and feels awesome, but it also puts the power of death in your hands. And that's a kind of thing 17-year-old versions of me don't need.

There is no virtue in being a harmless man, this sort of thinking is symptomatic of the ongoing problem with masculinity in the Western world.

That being said, the google data does seem to be true in terms of a lack of search interest, at least in the Anglosphere. Here it is for "spud gun":



This incident in Australia linked to in the article is quite horrific, it definitely trumps "frog boy" as a cautionary tale:

While checking if the projectile, a rubber bike handle grip wrapped in electrical tape, still worked, Mitchell fired a shot that hit Daniel in the face.

He told police he thought Daniel had stepped clear of the gun at the time.

The projectile lodged into Daniel’s face and he was rushed to hospital.

He died eight days later.

This "well informed" Vice reporter certainly has some interesting opinions...

Shooting a potato cannon is a lot like masturbating that very first time.

hmm...

farcticox1 wrote:Making a super simple 0.177 BB pistol, going to be muzzle loading, have some parts already, waiting for 1/4" Ebay QEV and compression fitting to attach barrel.

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Made a new M5 port on the side of the trigger valve so I can keep the top profile low.

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Just got the 1/4" QEV from Ebay and it hasa 3/8 exhaust port

No one:


Chinese QEV manufacturers: ¯\_(ツ)_/¯