SpudFiles

I just looked at an mythbuster and they builded an steam power cannon.

The design is simple:

1 compression chamber

1 pneumatically modded ballvalve

1 barrel

How it works:
you put water in the chamber, heat it with charcoals around it and wait until you get a decent pressure and open ballvalve.

Very simple, and Mythbuster throwed a 22 pounds projectile at 1 mile with 60 psi


This is very practical because you only need to put water in the chamber and wait, and after a few shot, the chamber is enough hot to fire at a pretty good rate of fire and no need of aircompressor.

(its sure it is not going to be in pvc...)

Does this already had been done here before?
I would like to see one of the spudfiles members do it

The episode i saw was a failing attempt at it because they had it preheated and then a valve to shoot the water in. Wish i saw one that actually worked.

(its sure it is not going to be in pvc...)

Lets hope not!

Edit:

Very simple, and Mythbuster throwed a 22 pounds projectile at 1 mile with 60 psi

If that were true, wouldn't that be the most powerful gun on spudfiles?

Oh dear, not another topic about the Mythbusters' cannons.

It won't be long before people start ranting about how the crew suck at building cannons - I quite agree, with their resources, their cannons could be awesome.

I've built very small steam guns, and contemplated doing this on a larger scale - it definitely trumps most pneumatic designs in terms of cost-effectiveness, but it really can't compete with hybrids unless you have the facilities to make your own high pressure steam valve and fittings. This is for a simple design.

If you want something that can be reloaded (i.e. a separate boiler supplying steam to the gun), you can forget about high pressure unless you're incredibly well off and have loads of time on your hands.

If, on the other hand, you're doing it for the tremendously spectacular muzzle blast effects that a big, high pressure steam gun creates, then go right ahead

Also, the Mythbusters used a pneumatically actuated butterfly valve, not a ball valve (and it wasn't rated for anywhere near the pressure/temperature they were hoping to run at, but failed to achieve due to lack of heating).

Ragnarok wrote:Oh dear, not another topic about the Mythbusters' cannons.

It won't be long before people start ranting about how the crew suck at building cannons - I quite agree, with their resources, their cannons could be awesome.

I second that notion!

They actually used a modified butterfly valve. I remember seeing that episode. What they got their idea from was MIT. They built a pretty powerful steam cannon and Mythbusters wanted to i guess "prove" it.

Interesting though. With a little guidance, they can be easily doubling their range with the materials they have at their disposal.

Lol what if they killed someone when they shot that cannonball! (I know, I know, im bad).

butterfly valve strike me as weak, the best option would probably be a burst disc.

I have seen that cannon, and the size of it was awesome, even though it wasn't a great cannon. And if I remember correctly the 1 mile shot was including how far the cannon ball rolled, which I think was pretty far. I wish I had their budget.

Unless you are really sure you know what you are doing, I would suggest you just skip it. I assume you also saw the exploding water heater episode and the utter devastation that is possible. Uncontrolled, safety valveless, high pressure steam experiments are a fool's errand.

Why not just go for a hybrid?

I want to challenge them to create a t-shirt gun that will get a t-shirt to fly a hundred yards.

We don't tell them about the site, and we wait until their done. Then we get Larda cut something out in an hour that beats whatever Adam and Jamie put together by about 70 yards.

DYI wrote:I've built very small steam guns

of course you have

And if I remember correctly the 1 mile shot was including how far the cannon ball rolled, which I think was pretty far.

Wrong, the cannonball landed and maked an hole, who proves he did not roll.

The main difference between their cannons and ours is that they seem to use very high pressures with slower valves, where we use lower pressures with faster valves.

I think our way is better- we can do more with less.