SpudFiles

Okay as the tilte says this is kind of a noob topic and there have been several similar ones lately but i seriously have $50 and no idea what to spend it on(not a lot to you but a hell of a lot of money to me).

1.Okay my thoughts are first a 158.276ci, 1.5in porting pvc triggered burst disk pnuematic. The problem with that is that it would be really annoying to pump up with such high volume estamated cost for that is $30.

2.Next turning my spray and pray into an advanced combustion but the problem is the chamber isnt pressure rated and i know people think non pressure rated pipe is fine for combustions but i am a cautious person.
101.75ci 2in porting exchangeable barrels, duel ignition, propane metered, chamber fan. Estimated cost $45. More money for something that would be less powerful than the first choice.

3.Make a mini adavanced combustion. 32.974ci 1in porting exchangeable barrels, duel ignition, propane metering, and a chamber fan. Estimated cost $40. the plus side of this over choice number two is that the chamber will be pressure rated.

4.start a metal high pressure triggered burst disk pneumatic similar to choice number 1 just out of metal. Estamated cost $120(I said start it I would finish it in a couple weeks if I do this).

5.Make a copper piston valved cannon. 30.171ci 1/2in porting QEV piloted.
estamated cost $50(there goes all my money)

6.make the excact same thing as in choice 5 just out of pvc. Estimated cost $10

7.Save it up for a compressor.

8.Save it up for a regulated scuba tank setup.

9.Get a shock pump.

10. Make the high pressure pump in gippedo's tutorial.


If you have any other ideas of what I should do please suggest them.

A small advance combustion should be a lot of fun...make something that shoots Nerf darts 8)

Definatly I have never made an adanced ombustion before and am keen to but the pnuematic ones do get more bang for the buck.

Choice #5 AND choice #10.

Depending on what you have "laying" around, if you were to forego the qev, you would have enough for both.

I have been "eyeballing" my pump for several days now. Not having something to really utilize it's potential has been driving me up the wall.

Sooo.. I went down to Home Hardware, and bought most of the stuff I will need for a 1/2" barrel, 3/4" chamber (using cut offs from the pump here) barrel sealing piston.

Maybe a copper hammer-piston? So far I have spent $13.27

for the copper gun i could pilot it with a 1/2in ball valve I have laying around instead of the QEV lowering the price to $30. and then Id have $20 to build your pump(might need to owe my dad some money).
But i would need to find a high pressure gauge which seems to not exist arond here I might have to order one online which i am not a fan of doing.
I dont have any of the required tools for soldering so that is why the copper gun is so much Im adding the price of the tools($10) to it.

why not # 5. there just isn't enough pretty copper launchers here. 3/4" piston made out of epoxy, 1/2" barrel 5' long and trigger it by a modded blowgun. no need for a QEV. use baby carrots for ammo and i'm guessing 800-900 fps for 500-600 ft. you'll probably want to build the high pressure pump also.

EDIT: you can epoxy the gun together. while i'm not a fan of using epoxy to attach fittings many people do use it.

I was thinking a 1in piston made of epoxy that ports to 1/2in beacause isnt the OD of 1/2in pipe larger than the ID of 3/4in pipe.

not even close

type L

1/2" OD .625"
3/4" ID . 785"

maybe a little close


for everything you need to know about copper.

http://www.copper.org/resources/pub_lis ... ndbook.pdf

Oh, wonderful Ill probably still go for a 1in chamber because I want to get some good power but Ill do a 3/4in piston valve which would lower my price a couple dollars.

this does not mean I have made my choice on what to build I just saying if I build it this is what I will do.
keep your opinions coming

A few more peoples opions would be nice

I find it best to work on more then one project at the same time, several reasons for this...

1) If you get pissed off with one project, (i.e you break a $7 guage, a $15 metal broided hose and a $15 regulator in the period of 15 minutes) you can just move on to another project to calm yourself down.

2) If you don't have the money to fund a project, but enough to start two or three, it's always more fun having more stuff to work on.

3) It's just fun working on a different project every now and then

4) No real time limit, you shouldn't have anyone breathing down your back asking when it will be finished, you just say you're working on three projects and they'll leave you alone.

I already have a couple projects that I have been working on the last couple of weeks but havent put much money into them. For example my mini coaxial, my 1/2in piston valve 3/8in porting, my 6mm chamber spray and pray the list goes on and on.
All those are nowhere near complete and i work on them when Im bored.

Okay sorry for the double post but I am wondering if it would be ok to use that just for copper stuff instead of soldering at 300psi

According to their data, the stuff has a shear strength of 710psi.

http://www.justforcopper.com/pdfs/Epoxy ... Sheet2.pdf


An example might be as follows;

3/4" type M od is .875". Joint length .75"

Area = pi *D *joint length

So... 3.14*.875 *.75

A =2.061 in2

So... 2.061in2 * 710psi

Fs= 1463.04 pounds

Divide by 4(Never trust things @ 100%) =356.76 pounds.(this is the allowable FORCE on the joint)

To get allowable PSI;

Using tube od of .875, Area of tube would be .601in2 (an end cap)

356.76pounds /.601in2 = 608.59 psi

To sum it up, you should be safe (IF you READ the instructions and follow them exactly) at 300psi.

Your life, or someone elses may depend on it. No joke!

Gippeto wrote: Your life, or someone elses may depend on it. No joke!

Well okay I think I'll use solder then unless normal high strength epoxy would be safer.