SAWED-OFF RIOT GUN redone!!!

[Velocity]

Wow, thats looking good. Im not sure if you answered this/its obvious to everyone but me, but what exactly is the piston seat on this gun?

It really does look powerful, especially with such a large-diameter barrel (for a gun of its size). This may/may not be true, but because you are running it at such high pressures, you could extended that barrel out a lot more than it already is (you don't need to add too much so that it makes the gun unwieldy) and gain incredible power

Either way, lookin good!

[)DEMON(]

Yep, I must say it is looking really good.

One question though brian, the barrel is bigger than the tee, what does the piston seal against?

[joannaardway]

I hadn't quite realised quite how small this was until I saw that picture of your brother holding it.

It always helps me when I see a person in the picture.

I personally would use a longer barrel for even more power - a barrel twice as long would dump a mass of extra energy into the projectile...

[Brian the brain]

I built it to look like a sawed off riot gun. A longer barrel would not look as good.the first version was long but it did not look that good.
I like the fact it is so small, yet so powerfull.
everybody else builds big cannons, I wanted to try the opposite, without it being wimpy.
The barrel is 28 mm copper, the tee is 28 mm.
The piston seals agains a rubber washer, wich is glued into a reducer.
So between the barrel and the Tee it's reduced to about 20 mm, wich still has enough flow, especially at 23 bar...

[CpTn_lAw]

What materials did you use?i mean every parts.i've designed my two future and last cannons..just need to have some money to buy the copper pipes.
One in 6mm or 8mm, and the other in 8mm or 10mm....the smaller one will be a piston handgun, and the bigger one will be a breech loading piston rifle, with stock, bolt action and 200 psi of pressure running through a 0.44g BB...hehe!

[schmanman]

I'm curious what it will look like in two years.

[Brian the brain]

This is how it all started:http://www.spudfiles.com/forums/viewtop ... 8976&#8976
the long version.

Now all pipes are steel, all fittings are brass.

[MrCrowley]

yeah i see your point,the sawed-off shotgun look is way better

[POS]

Brain, the chamber, is it copper to ? 28 mm ?

Just one more question. Why did you use treaded parts ? Isn't soldering stronger ?

And where the hell do you get 23 bar

[-Skate-]

Hot Damn! Nicest thing I have seen!

[Brian the brain]

I found steel 28 mm pipes in a shop called "Karwei"in holland.
I use Compression fittings ( knelkoppelingen) because it's like Lego.
You can take everything apart, clean, change it around.

The compression fittings hold the pressure very well.
I have a Rennkompressor pump, wich is supposed to go to 16 bar, but I just keep pumping, and, with a lot of effort I get it up to 23 bar.

[killagorrila99]

http://www.spudfiles.com/forums/viewtop ... 922&#46922 .

Check that puppy out brian.

[Brian the brain]

I did.We have the same taste.
Very big pilot volume from what I can see...or did you fill it up for the most part??

I suggest you find a way of attaching a 90* bend onto the ballvalve lever, and cut off the remaining bit, so it's at a better angle

[killagorrila99]

The schrader is behind a one way check valve (back flow preventer) that only lets air into the chamber, and none goes back into that area.

[Brian the brain]

I busted my pump about a week ago!!!THe one that could do 23 bar!!
The hose got forked up..Worse even is I can not order a new one!!
I would have to buy a new pump, wich was VERY expensive!

Now I didn't want to be without a high pressure source, so I got to work:

I removed the busted hose and replaced it with a modified plug, sealing off the hole.
I unscrewed the 1/4"pressure gauge and fitted a ballvalve with two 1/4"side channels into the "new"outlet.
I capped one end of the ballvalve, so with the ball closed, air can only go to the other side channel.
With some fittings I connected a female QD-fitting on top.

The sawed off now has a male QD with a schrader valve inside of it ( works like a charm)
I simply "click"the gun onto the pump,
pump it up to 23 bar, bleed through the ballvalve
and "quick" disconnect!!!

It works better than before!!!It's faster and looks real pro.
I sprayed all the added fittings black.If I can find the fittings , I'll even install the gauge back into the now sealed end of the ballvalve.
The pump now seems to be custom designed for the sawed-off!!!

I'm so happy I could fix the problem in such a cool way.