SpudFiles

again im going on about this i wanna know will quick connect on a bottle provide enough water to leave to launch up in the air?
if not how can i get an o-ring on a pvc pipe with a poket knife saw or any other way?

Ugh. Put some effort in your posts, please.
Im going to try to translate/understand what you're saying here:

again im going on about this
I have another question about this.
i wanna know will quick connect on a bottle provide enough water to leave to launch up in the air?
I'd like to know if a quick connect on a bottle will allow enough water to flow out of the water bottle rocket so that it provides enough thrust to launch.
if not how can i get an o-ring on a pvc pipe with a poket knife saw or any other way?
If this isn't the case, is there a way to make a proper o-ring groove in a pvc pipe with a pocket knife saw, or another simple tool?

In answer to the first question: I believe a male 1/4" quick connect has a 5.5mm diameter hole through it, without obstructions. I don't have much experience with water bottle rockets, but a nozzle is a good thing. You should search for the effects of nozzle diameters on thrust and find out whether a 5.5mm nozzle is a good diameter. (5.5 mm ID is a standard, but this may not be the case with your quick connect, I just measured one over here and it was about 5mm, so MEASURE!)

I do not think you can make a proper o-ring groove with a pocket knife saw or similar tools.

5.0 mm = 0.196"

Implies a cross sectional area of .03 sq in. At 100 psi (about the "nominal" capability of a 2 L bottle) you're talking 3 pounds of thrust.

AT BEST.

D_Hall wrote:5.0 mm = 0.196"

Implies a cross sectional area of .03 sq in. At 100 psi (about the "nominal" capability of a 2 L bottle) you're talking 3 pounds of thrust.

AT BEST.

I've had very good luck simply not using a nozzle on the bottle. In the video, the attempt to toss the bottle creates a shifting load. I've done one launch pad with a rubber stopper with a copper tube in it with a double sear (clamp) with a string pull release that provides very stable flights. I also made a barrel for my marshmallow cannon that simply fits snugly in the neck of a soda bottle. It is a simple aim and trip the cannon to launch. The mass of the rocket ensures the bottle receives a good air charge before departing from the launch post. The post in the bottle works well in providing the bottle a stable launch. The hard part is trying not to flinch when launching it as you know you are gonna get soaked. Sorry no video of these launchers.

You can easily put a groove for an O-ring in PVC with a triangular file. Heck, if you are careful you can use pretty much any type of file. Just take your time.

Garden hose quick connects have been used as both fill ports and launch nozzles. IIRC, the nozzle is a bit too small to be efficient but it's simple to do.
http://www.xinventions.com/main/spud/rocket.htm

5.0 mm = 0.196"

Implies a cross sectional area of .03 sq in. At 100 psi (about the "nominal" capability of a 2 L bottle) you're talking 3 pounds of thrust.

AT BEST.

IIRC, the garden hose quick connect is 9mm (.35") ID. That gives a thrust at 100 PSIG charge of ~10 pounds (Thrust = 2PA). At lift off a 2L bottle + water probably weighs about 1300g (3 lb). Just before "burn out" the rocket's weight is only a few tens of grams and the pressure has dropped ~3x. The thrust is way down but the rocket weighs almost nothing just before burn out.

A water rocket doesn't really need all that much thrust. And, a smaller nozzle gives lower thrust but for a longer time than a larger nozzle.

Personally though, I think the unmodified bottle neck works fine. Google for "Clark Cable Launcher" for a pretty simple trigger system that can be operated remotely. With remote operation you can pressurize the bottle up to 200 PSIG.