SpudFiles

BTIS SPA?
Ok, fine, spray and pray with removable barrels.
(Updated in response to comments)
Brief history of my spud guns:
1st Gen: Ungainly 2ft 4" chamber with badly sealed spark wires. Parted out. Fired intermittently, Hair spray fuel.
2nd Gen: Interchangable barrel and straight or U adapter, still ungainly 2ft firing chamber. Sold. Fires reliably, Equate deodorant fuel, consistent power

3rd Gen(pictured): High pressure(non combustion) 1ft chamber with discharge valve, interchangable barrels and chamber.
Other chamber is 1ft, generic Right Guard fuel, spray 'n' pray(unreliable fire/power).
Assembly adapter(U or Straight) was destroyed by the lawnmower, so it's not pictured.

(From bottom to top)
Third generation, 4x12" combustion chamber with thread adapter for no-interchange assembly
2" Spud and mini-tennisball Cellular Smasher*
1 1/2" thinwall Golf Ball Barrel (perfect fit, raquetballs too)
1" This Looks Like a Weapon barrel(mouse balls, bolts with 3/8" rubber foot for semi-attached wad)
3" Anything that Fits barrel(lost the wad)
~145PSI 1-gallon pressure tank*
*Google video of pressure shot with 2" barrel
http://www.youtube.com/watch?v=VHlR5U-gBaA

Trying to follow your description is making my head hurt. You talk about 3 different spud chambers and show 2 of them, I think... I have no idea what the use of the "hand-valve pressure chamber" is ... even less after seeing it in the picture. ...then the whole H piece/U construction/destructive encounters with a lawn mower thing totally confounds me.

Perhaps some more detailed pictures would help your description. While showing some gratuitous cell phone destruction, your video was almost useless in helping us see the operation of your gun.

To sum at this point, it looks like you have a basic spray and pray with an exchangable barrel system.

BTW, Welcome to Spudfiles!

it looks like he has a ball valve pneumatic and a spray and pray combustion, both with interchangeable barrels

(BTW the above assessment is correct about what I had)

Arranged with the seal cap facing forward with the barrel and a short length opposite barrel on a 'h' joint makes an ok simple shoulder rest.

That placement also makes it ideal to avoid injury when the thing blows apart on you!

The end thread adapter, kept from the "1st gen" spray and pray(which worked a lot better) shot off on me! Apparently I hadn't followed adhesive protocol as well as I do now, and the recoil from 2lb of pvc shooting off knocked me over, in addition to snapping my jaw hard enough to chip a tooth.

I am well enough educated to know better than trusting plastic and glue to contain an unpredictable explosion, and am lucky I didn't get burned or worse from it. I'm moving to full pneumatic(hybrid is too expensive) and the physicist in me said they don't need a huge tank(1/4 barrel volume) if they handle high pressure(steel, 200+PSI) and the result of that is a very quiet launcher. I'll repost once I get pictures of it.

If you can make a steel pneumatic, throw in a coupler and a spark plug and voila, you have a hybrid.

Moonbogg wrote:If you can make a steel pneumatic, throw in a coupler and a spark plug and voila, you have a hybrid.

The point is a *cheap*, very quiet, highly portable(needing to lug or purchase fuel defeats that) launcher.

It's an "without being a gun" ambition, not a "look at my really big gun" one.
I saw your video, you could launch artillery with that beast! Fix your breech seal!!

Ah. You want something inconspicuous and low profile while remaining potent. How do you plan on adding the air to the chamber?

Moonbogg wrote:Ah. You want something inconspicuous and low profile while remaining potent. How do you plan on adding the air to the chamber?

Going to either gut/modify an auto compressor or use a hand pump(which I haven't tested at high(>80psi) pressure.) Not inconspicuous, and puts a lie to my 'lugging' complaint, but if that's the loudest component, hoorah!(Which for now, it is.)

I have definitely become a fan of interchangeable barrels. It makes ammo selection a lot easier.