Stage whistlerockets

[Weirdo]

Hello all.

 

 

 

 

I'm testing with stage rockets. I made a 2 stage 14 mm rocket and it worked. But the method of making it wasn't very good because it will only work with 14 mm or smaller and only for a 2 stage.

 

http://www.pyrotube....-20-grams-flash

 

 

 

 

I made the rocket by pressing 2 identical rockets, with some kraft I rolled a tube from 3 cm long and put it for half over the upside of the first motor. So the second motor can be shoved in. Only glue it at the first motor. leave the open space for what it is.

 

 

Like this.

 

 

 

 

Than put a strand of BM in the core of the second motor and shove it in the kraft rol. Do not glue the motor in, it will have a tight fit, maybe reinforce it with some papertape. But loose enough the rocket can fly out of it. You only need to tape the second motor on the rocketstick, if the second stage is taking fire it will blow the first stage away, If you tape the first stage to the stick to it will result in a CATO.

 

 

Like this.

 

 

 

 

Now this works fine for smaller motors. Now I do want to make a 3stage rocket with (ofcourse) bigger motors. Do anyone know a decent design for a stage rocket. I did read several methods with bentonite endplugs and quickmatch. Rubyred delays but no good descriptions of pictures how to make one.

 

Can anyone help me?

[Arthur]

You may have trouble with the stick and the balance of the assembly. Usually the stick assists the balance of a rocket, but when the first stage drops off the tube CoG changes so the stick shape needed changes. Most amateur rocketry people will use a fin stabilised system with three or four fins low down on the body of the rocket.

 

What is the value of a rocket that flies so high that it goes out of sight?? Usually a rocket is used to lift a payload of stars to a fair height for a safe break BUT not so high that they cannot be seen!

[Weirdo]

I know it will fly really high. But I like stage rockets. There doesn't have to be a payload on the rocket . Also I really like to know a good technique to make 3 stage rockts because I couldn't think of one.

[Arthur]

Possibly there isn't a design for a multi stage stick stabilised rocket simply due to the changing dynamics of the structure as the stages separate.

[Weirdo]

Hhhm, that will be hard to make one than. I was inspired by this movie

. And here's anotherone.

Edited April 18, 2010 by Weirdo

[dagabu]

This is a Dan Thames rocket two stage rocket shot at PGI. Use the same idea of the two sticks (or three) to add stabilization. Long sticks may give you the stabilization but make sure they are thin and evenly spaced so that the acceleration of the whistle fuel doesn't pitch the rocket sideways. Three stage rockets are made the same way but use four sticks, two attached to the lower motor and two attached to the second motor, the third is finned. http://www.pyrobin.com/files/img_1067_5.jpg

[Mumbles]

To make three stage rockets you need to be able to attach the motors to the stick. I've never done it, but I've seen cplmac make them. I can try to describe it.

 

He tapes the motors on with masking tape. On the bottom two motors he slits the masking tape around 1/2 the way through. This gives it strength while it is going up, but when the next motor kicks in, the downward thrust on the tape makes it tear like butter. I think he only uses one strip, maybe 2 turns, around the middle of the tube, but don't quote me on that.

[dagabu]

I tried that instruction last year at PGI and had the top stage detach since the joining ring wasn't strong enough. I like the kraft Idea But I take it a step further and use gummed kraft tape. I will have to take a pic to show you, words escape me but essentially, there is 1 layer of tape missing from the loose joint where the top rocket fits in with the middle etc.

 

D

 

Edited April 19, 2010 by dagabu

[ausfire]

Here is one of my 2 stage whistle rockets from some time back. It consisted of two 1lb whistle motors the first stage being 4" in length and the second being 5", joined by an internal coupling. If i can remember correctly it took at least three attempts before i had the second stage working correctly most of the problems being caused by overpressure from the burnout of the first stage. This was eventually fixed by pressing approximately 1/4" of BP at the top of the first stage.

 

Benzoate/Oxychloride catalyzed whistle fuel + 7 Gram 70/30 salute

 

http://www.pyrobin.c...le%20rocket.wmv

[Weirdo]

Woow, thank you all very much for those clear photo's and instructions. I see it is a little harder than I expected, but that isn't a problem, because the harder is is to make the more fun I have I like challenges. I am going to try one soon. I only need to go looking for a good connection between the 2 rockets without Cato'ing the second rocket. I think I will use less core on the second one to prevent cato'ing.

[jimbo]

that was awsome man good effort, love whistle rockets how high do ya reckon it went, you might be able to get a rough estimate measuring the time of the flash till when you can hear the report goin off like how you measure how far lightning is away

[dagabu]

Great timing on that question:

 

http://www.pyrobin.c...20distances.pdf

 

Weirdo, I agree, the second stage is the tricky one as it gets over pressurized real fast and will CATO if not buffered. I was told last year to press in BP at the end of the motor to shorten the spindle length for the whistle and to use NC lacquer on the whistle to make a retarder layer so that the two stages are fully separated before the second stage spikes.

Edited June 15, 2010 by dagabu

[Weirdo]

Thanks for the clear advices This will bring me much closer to an succes.

 

I really like that document of rocketheights to.

Its really smart to press some BP at the begining from the second stage, bp isn't as strong as whistle, so the maskingtape has his chance to rip by the BP, and than the whistle strikes in whithout any chance of cato'ing.

 

The theorie already works, now lets hope it will work in practice

[dagabu]

Lets revisit the fuel...

 

I found that two stage whistles are doable when you tame the fuel down for the second stage and retard the burn area with a coating of NCL. I have switched from whistle to hybrid fuel for the bottom stage and a slow K-Benzo whistle (Mineral oil) for the upper stage.

 

I also am using PVC fins on the upper stage with no sticks. I will see if I can make and shoot one this fall and post it here.

[Weirdo]

Thats a really nice idea to, I think I need to make me another batch of whistle, the 70/30 KCLO4 / Sodium benzoate That whistle will do the trick.

[dagabu]

I spoke too soon, I am still having problems with the top CATOing when the top over pressures. I think that a nice BP nozzleless is my next try on a two stage, I like pretty BP tails anyway.

 

18 rockets went up this past Saturday, I will post links to the non-mines on a stick when I get some time

[Juiceh]

18 rockets went up this past Saturday, I will post links to the non-mines on a stick when I get some time

Post the mines on a stick too! I love a good CATO!

[dagabu]

I have not had any time to put the video together, I will post them all in one compilation.

 

I got the word since my last post that I can always do a nozzleless with whistle pressed above the spindle to get the whistle. I will stay with the Hybrid for the bottom stage due to the additional thrust but whistle for the bottom stage breaks the second stage off.