My New 16L Rocket

[DogLover]

Hello!!
Here is a picture of my 16L rocket I am going to launch this Saturday.

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I was a little concerned that the fins on the lower rocket isn't enough to stabilize the whole thing, so I added the fin ring back to the green rocket. I hope this will stabilize it enough.

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Here is the camera setup that I have. I plan on putting half a PET cone over top so that the air flows a little smoother.

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I made a parachute that is about twice the size of the one I use for a 8L. I am hopping that this will work.

-DogLover

[Brian]

That's a big rocket! I'm not sure how well a gardena nozzle will lift such a large rocket.

[DogLover]

I ran a simulation of it and it looks like it will work!!

-DogLover

[Brian]

Do you have a long guide rail? The rockets going to have a slow take off.

[U.S. Water Rockets1]

I ran a simulation of it and it looks like it will work!!

-DogLover

That rocket is massive. It is impressive just sitting on the ground. How did the flights go? Do you have any launch reports?

[DogLover]

Howdy!!!

The rocket immediately began to turn once it launched, as soon as it left the guide rail. It got to a total altitude of about 25' but went about 500' horizontally. My brother (camera man) said that it sounded like a jet coming toward him!!! I plan on putting up some video once I can get it edited together! It ended up that I broke it half, the size of the regular 8L rocket, and I got a good launch, but the wind carried it almost into a lake. In fact, the nose of the rocket was in the water by about 2". The next launch, the parachute didn't deploy. I need to redesign the system a bit so that the string can't get caught, which is what happened. I also noticed on that last launch, there was a pin hole in the bottom spliced pair. I think I might try to repair it using PLP, but I don't know. It has taken a HUGE number of crashes, and I think that the only thing that kept it together was the glass strapping tape it was wrapped in! Then I launched my 0.5L demonstration rocket, and it worked perfectly for the first 3 launches. Then the parachutes didn't deploy, because the string got stuck, and when it crashed a fins came off. Oh, I forgot! Before the launch we had some double chocolate muffins. I don't know if that helped or hurt :/

-DogLover

[Nick B]

gardena nozzles suck.

[DogLover]

I have to admit that they are looking worse and worse. However I am not quite ready to throw them out yet.

-DogLover

[Nick B]

They are not too bad if you can back them up with some decent pressure or with smaller rockets, but large rockets are problematic.

Even if you look at George's larger rockets, you see many of them reinforced when larger for more pressure, or nozzles modified or purchased with larger IDs.

You can probably launch a 10L rocket without a guide rail at 200 psi, with a 12mm id coupler, if the coupler releases it smoothly, and if the pet bottles could hold that pressure in OEM form. But that's just not the case.

Maybe double back to 6 liters and start over.

[Tone]

good work on the rocket, i have made similar and used the same nozzle.
I found the drag and COP, COG calculations need to be spot on to stop rotation of large rockets, mine did the same, was pretty cool, the garden nozzle i use i drill out and make an attaching part on the inside to smooth out the flow, once i sized the fins and got the mass centre right it worked great

[DogLover]

I just did that to see if it would work. I was not attending to replace my 8L rockets with the 16L. I would like to have put in more PSI, but my pump won't get that high! I plan on starting with staged rockets. I think that might work better. Another thing I am playing around with is to make a attachment that will allow me to launch full bore rockets. The way my launcher is designed is the female quick connect screws onto the launch pad. I am thinking about creating a launch tube that will screw on once I take the female quick connect off. I hope that this will work.

-DogLover

[U.S. Water Rockets1]

good work on the rocket, i have made similar and used the same nozzle.
I found the drag and COP, COG calculations need to be spot on to stop rotation of large rockets, mine did the same, was pretty cool, the garden nozzle i use i drill out and make an attaching part on the inside to smooth out the flow, once i sized the fins and got the mass centre right it worked great

Our early home built rockets used a small pressure vessel with a large cardboard tube for aerodynamics, and used a nozzle clamped into a bike pump for thrust. The launch mechanism was the release lever for the pump that clamps it to the tire. When we went with a larger pressure vessel, we experienced the same issues with the rocket tilting over. This was before the internet, so there was nothing published about this stuff, but that was one of the early lessons. Large heavy rockets tilt over with small nozzles. :-(

[Nick B]

I just did that to see if it would work. I was not attending to replace my 8L rockets with the 16L. I would like to have put in more PSI, but my pump won't get that high! I plan on starting with staged rockets. I think that might work better. Another thing I am playing around with is to make a attachment that will allow me to launch full bore rockets. The way my launcher is designed is the female quick connect screws onto the launch pad. I am thinking about creating a launch tube that will screw on once I take the female quick connect off. I hope that this will work.

-DogLover

Or you could just add another tee and a launch tube.

My fun time launcher has both a qdc tee and a launch tube tee.

Granted, it limits my launch pressures with qdc rockets to 120 psi,... and with full bore rockets, to around 220 psi, depending on which qdc plug I use, if the launch tube is filled with water, air temp, ect..