Get SCH 40 2 inch barrel (36 to 48 inches), 2 to 1-1/2 threaded bushing, a 2 inch coupling and some of these for a fun time.
Check at your local dollar stores for best prices!

dewey-1
I just plan on using a schrader valve to fill the chamber, so I don't think I will need the extra valve or a regulator to fill it.

The real benifit is the small guage that is on the flow regulator.
Harbor Freight sells them cheap. You can still use a threaded Schrader valve.
You will need ...

A flow regulator will control the "fill" rate and be much cheaper and smaller than what dart guy is proposing.

http://www.harborfreight.com/125-psi-air-flow-regulator-with-gauge-68219.html

You can see one in the 3D model attached.
The overall length of this model is 36 inches.

Edit to update ...

I use these inflators:

http://www.ebay.com/itm/220-PSI-Lock-On ... ea&vxp=mtr

ascientist wrote:dewey-1
Thanks for the links. Would 3 inch be a little overkill for a portable launcher? The price is very tempting.

Look at the Flex Kleen valves, new and cheap.

A trigger style will help the accuracy of the shot.

Here are some more:

http://www.spudfiles.com/forums/asco-valve-t12997.html

http://www.spudfiles.com/forums/john-daly-t20239.html

Another Asco
http://www.ebay.com/itm/ASCO-DIAPHRAGM-VALVE-1-1-2-FLEX-KLEEN-M28244-NEW-NO-BOX-/170994323797

http ...

Would you recommend this valve?
http://www.ebay.com/itm/Asco-JFK8353J39-Dust-Collector-Solenoid-Valve-8353J39-1-1-2-N-C-2-Way-NEW-/290958430376?pt=BI_Pumps&hash=item43be7950a8
I'm all for just buying a valve, but am having a hard time finding/identifying an appropriate one for purchase.

Look for ...

This should be what you need!

http://www.ebay.com/itm/M22-x-3-8-MPT-P ... vi-content

View this link for what you might want.

http://www.antennalaunchers.com/csv19/index.html

Sadly the darts did not live up to expectations.

Darts: shot- results
We shot the darts today. None of them worked. It seemed the fins were stripped off or broke off at the moment they left the barrel, so the rods just tumbled through the air. The 3 bolts that you made worked very well, and were ...

I could be that the large mouth of your chamber is allowing the gas to escape. Inject slowly, and with the syringe nozzle as close to the "bottom" of the chamber as possible.

Also, 3cm² sounds far too low for your chamber size. It looks like you have a volume greater than one litre from ...

Then try this:

http://users.telenet.be/elvo/8/4_content.html

jackssmirkingrevenge wrote:Not on this one mate, I have a month left to sell it!

Getting excited to enjoy fall in Quebec?
Do plan on any outdoor hunting and fishing activities (not women) when you finally move there?

Sorry i kinda ment that you should shape a block of lead like the fins and body like the aluminum then you should take the hardest metal you have and make that the actual dart.

You can not use lead for the fins and body due to the weight. Please research CG and CP for a better understanding of ...

duane;
Have you considered using a 5 pound fire extinquisher as a chamber?
It is about 14.5 inches and 4 inch diameter.
http://sketchup.google.com/3dwarehouse/details?mid=46224aa86d2e78de8b92e236cf9045a7&prevstart=0

A 3/4 inch QEV may actually be a better choice than a 1 inch sprinkler valve ...