12 replies to this topic

[ShadowSniper]

Well, I just got done messing around with my newest homemade and I have to say that this thing is by far too dangerous at full power to be used in a war.

Basically, I have an air tank on the bottom made out of 2" pvc pipe, a bike valve in the cap on that, two 90 degree angles bringing it back around where I have a 3/4" sprinkler valve and finally, a threaded 3/4"connector so that it has interchangeable barrels. I also put a mock scope on top for looks (It can easily be taken off).

So far I have a 1/2" barrel that I secured some brass inside for shooting stefans, and a 3/4" barrel for shooting whatever I want. I dont have any pictures yet but I will try to get some on here later in the day after the paint has dried.

Anyways, on to the meat of the topic...what it does. 1st off, I took a 5" piece of 1/2" CPVC pipe and flared out one end using a heat gun so that it fits almost perfectly in the 3/4" barrel, after sealing the other end and adding a weight, I shot it at 20 PSI. It went about 100' and spun around as it went. Further refining of the rocket got it up to around 130' with no spinning. Then I increased the power to 80 PSI...the thing went so fast I couldnt see it and went well over 300' (How far it was to the pond and the rocket was still fllying past it). I wasnt able to retrieve the rocket due to it bieng lost in the forest so I decided to try it out on stefans. Skipping the 20 PSI stage I just primed it up to 80 PSI and let 'er rip. The stefan went about five feet. >.<

Further inspection of the stafan showed that when fired, the air tore out the middle of it and shot the glue/wieght into the bamboo forest (150' away). I havent gotten around to shooting stefans at a lower pressure yet due to my impatience to paint and post this but I'm assuming that I can sucessfully shoot a stefan at a much lower pressure.

I plan on later on, hooking up a bike pump to the side of it for shooting on the go, but I ran into a snag with the sprinkler valve. I used These instructions as a starting point and did a coupla things differently to suit my sprinkler valve. Basically I epoxied up a few things that were on mine but not on that one. But when I first tryed to fill up the tank, I heard a strange noise and the air was coming out of the barrel. The only way I could find out to remedy this was to pressurise inside the solenoid (opposite side of the diaphragm than the tank/barrel air) first so that it wouldnt open. if anyone has experience with this, how do I fix this or do I need to get a different valve? Just for no confusion, it DOES work I just would like to have it so that I dont have to pressurize two things.

Anyways, as said earlier, I'm going to try to get some pics up as soon as I can.

Edit: Pics are here!

Overview


Right Side


Left Side


Barrel Shot (Shows Nested brass barrel)


I didnt bother taking a pic of the other barrel seeing as it looks the same only a little bit bigger and withought the brass. anyways enjoy!

Edited by ShadowSniper, 21 March 2006 - 12:21 AM.

[GeneralPrimevil]

Sounds like the oen I'm working on currently. The only difference is my valve is better . I'm not going to tell you what it is; I want everyone to guess. DB, hold off before you say anything. Mmm...power....

Pics! Pics!

That problematic valve is the reason why I only bought one sprinkler valve...ever. I hated it. Pressurizing two things isn't too hard to accomplish with a tee fitting between the pilot hole and pilot valve with a hose going from the tee to the tank. That way both are pressureized simultaneously. I'll elaborate with an image later. Too lazy right now.

[davidbowie]

Try checking the seat on your valve for any sort of debris. That's the problem i've had most with sprinkler valves that refuse to seat.

[m15399]

General, I'm guessing Dr. Nerf style piston, or Spud Tee style piston valve?

Pics please (both of you)!

[GeneralPrimevil]

Damn you...barrel sealing coaxial.

It's not quite fully finished...yet. When it is, everyone will know. Currently, my head just started bleading for no reason. Please stand by while I go get some duct tape...and a glass of orange soda.

Anyway, all I need is the 2" PVC and fittings for the chamber. Apparently I have nothing for 2". Everything else is made, including the pilot vavle, barrel, fill valve, pump I need to work on, yeah. No hi-jack. Do we look terrorist?

Pics! Pics! Death! Pics!




Edit: Wee! 300th post! I feel like "The Simpsons" in the year 2003?

Edited by GeneralPrimevil, 20 March 2006 - 08:55 PM.

[ShadowSniper]

Ok, looks like I got the pics up. Enjoy!

Also, GeneralPrimevil, I'd like to see this gun your talking about, sounds interesting...especially if it has a better type of valve, this stupid double filling thing is annoying. Luckily the sprinkler valve isnt glued in (just used teflon tape or whatever it's called).

tee fitting between the pilot hole and pilot valve with a hose going from the tee to the tank. That way both are pressureized simultaneously. I'll elaborate with an image later. Too lazy right now.

Could you elaborate on this...I cant seem to get a mental picture of it.

Edited by ShadowSniper, 21 March 2006 - 12:25 AM.

[davidbowie]

a sprinkler valve shouldn't have to be filled from both sides. Try troubleshooting it for a bit, and it should be able to seal. Take off the bonnet, clean the diaphragm and sealing face thoroughly, check for any pvc shavings inside the valve, etc. It might help to fill the chamber with water, slosh it around, and then pour it out, to get any shavings out of it.

[GeneralPrimevil]

I should hopefully have it up tomorrow. I might even have that previous all-steel project done. That would be nice...

Nice job on that homemade. You should invest in barbed fittings and rubber hose to get that blowgun off of the valve. Then you could put it (almost) anywhere on the gun.

Umm...I think I'll make a Paint drawing real quick and post it right below this sentence...

"Der Shiza" Image

Don't laugh. That is my worst Paint image ever. I mean, ever. It took literally a little less than four minutes to make.

[davidbowie]

That would hurt the performance quite a bit, because the blowgun would have to exhaust the pilot volume plus all the air that keeps coming in.

Seriously, your valve should seat normally. Make sure it's all clean, and put back together correctly (diaphragm put in right, spring installed, etc.), and try again.

[ompa]

Shadow, do your stefans have holes in the back? Try un-holed stefans, then you wouldn't have that problem. Your darts will still probably spin out unless you use some crazy-ass weight like 2-3 7/0 weights. I think they're fishing weights; I'm just suggesting them because they're the heaviest weights I've heard used around here.

A basic gun, but very functional and nice-looking.

And you guys hijacked his thread. I mean you guys took him by the fucking neck and forcibly took this thread.

~ompa

Edited by ompa, 21 March 2006 - 07:21 PM.

[GeneralPrimevil]

I've used 1/2oz. bass sinkers before. That hurt like a bitch to get shot though...
How much do 7/0's weigh? I don't seem to have any in my tackle box. The largest I have are 5/0's which are really light compared to the 1/2oz bullet sinkers.


Of course there would be a valve between the tee and the chamber. I just forgot to throw it in that Paint image. Na ja...Just do what DB said.


What did we do? My homemade? I'm trying to keep people from talking about it by saying that its not done yet. As for that valve comment, with barrel bores like these, I'm not sure if mine will perform any better. I know that it will not look as good as SS's gun since he has good lines and designed it a bit more ergonomically than mine.

[Pineapple]

Nice work, ShadowSniper. You'll discover that it doesn't take much pressure to get stefans to fly good distances. Save the higher PSI for chucking your bigger stuff (like PVC darts).

I'm having similar problems with my artillery, with a 1 1/2" Hunter valve. That "leak" caused me to shelf the project for awhile, and it kind of took the wind out of my sails regarding "spud" gun conversions (mine and my brother-in-law's smaller rifles with 1" valves have been working with decent success, so I'm kind of stumped on this one. )

davidbowie, I must've taken apart and cleaned the diaphragm a dozen times, double checked the fit to the body halves, and tightened the case bolts securely. Still leaks out of the front, and activating the valve brings about a 'puff', instead of a surge. This Hunter ICV valve series may have some amendments to reduce 'water hammer' that may be impeding my work on modding it.

EDIT; After reviewing the working drawing on the Hunter site, it may be the location of my bleed-off gun. The hole where the solenoid once was (where I put my bleed-off) appears to be way too small for the 1 1/2" valve (but fine for the 1"), so I may need to drill/tap a port into the top half of the case, then mount my bleed-off there (forgive my layman's terminology). The ICV's have a guide rod and regulator, so it'll be tricky to do, but that appears to be my next step.

Anyways, good show, chaps. It's nice to see everyone really pick up on the air-powered homemades (since Boltsniper, Carbon, and the others are killing me with their really cool springers.)


-Piney-

[GeneralPrimevil]

10 psi? Wow, nust have good air usage. I remember a ball valve homemade I made awhile back that barely had good results with 80. It was a crappy design with a shitty ratio, but still...

I don't like springers; too many high-stress parts, unlike pneumatics in which everything is high-stress (or low stress, depending on operating pressure).

Edited by GeneralPrimevil, 22 March 2006 - 08:13 PM.