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Rocket failure to launch


Leatherlips

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Hair splitting accepted and noted, thanks WC! :P

 

**Update**

 

This from:

 

BLACK POWDER JARGON AND DEFINTIONS

By Scott Jay and Kurt Medlin

‘Scratch mix,’ ‘hand-mixed black powder,’ ‘Home Powder’ – Colloquial terms used to describe an unprocessed version of black powder, usually a simple hand sieved mixture of potassium nitrate, charcoal and sulfur, typically in proportions around 75:15:10 which burns much slower than commercial black powder. Note that these are unprocessed mixtures made without a binder, without milling, and are not pressed, corned or water-granulated.

Edited by dagabu
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"If it does pop, back off from pressing the entire motor with the hot BP and use your glitter on top to tame the fast BP"


Just one more clarification please. When you say to "use your glitter on top to tame..." , would that mean to use the hot BP in the initial increments, then use the old fuel in additional increments (even more than just above the spindle(normal delay))? or would I try to mix the two (hot and glitter) together and press the whole engine that way?


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Yes, that is kind of a 'rule of thumb' in rocket motors, use the hottest fuel first and switch to the less energetic fuel after that. Following what SLD has told hundreds of us over the years, "Keep adding more increments of the (hot fuel) until it pops then back off one increment."

 

That's the "red line" for the propellant, the most thrust, highest impulse in that particular configuration.

 

You can certainly mix them but you will likely lose your desired effect of the glitter doing that.

Edited by dagabu
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Hair splitting accepted and noted, thanks WC! :P

 

**Update**

 

This from:

 

BLACK POWDER JARGON AND DEFINTIONS

By Scott Jay and Kurt Medlin

‘Scratch mix,’ ‘hand-mixed black powder,’ ‘Home Powder’ – Colloquial terms used to describe an unprocessed version of black powder, usually a simple hand sieved mixture of potassium nitrate, charcoal and sulfur, typically in proportions around 75:15:10 which burns much slower than commercial black powder. Note that these are unprocessed mixtures made without a binder, without milling, and are not pressed, corned or water-granulated.

 

Few things-

 

1. You STILL spelled his name wrong-

2. That definition makes your original statement even more misleading, he granulated BP in order to copy Ned's "unprocessed, non-granulated" BP? <_<

3. The terms "home powder, scratch mix, green mix" etc carry a certain level on ambiguity, other chemicals are often added to them, depending on the desired application. I would say the big distinction comes upon milling.

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I'm not sure if Leatherlips actually mentioned having a ballmill. Nevertheless, a possible "quick fix" solution does not address the underlying problems that Lips is having.

 

I have a similar issue making flapjacks - I can never remember the recipe, it's always far too watery. My "LAZY" way out is to just put some more flour in. It then becomes very lumpy so I have to spend considerable time getting the lumps out. It all works out sort of fine in the end and I get away with it. I guess I should try to remember the proper recipe for next time, but I never can. Afterall it's not pyrotechnics, it's only flapjacks.

 

Cheers.

What's a flapjack?

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What's a flapjack?

 

Pancakes down under. ;)

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Dagbu, 70/30 is 70 alcohol 30 water? (Denatured or rubbing, or doesn't matter?)

I did create a tube support from pvc last night. I'll give this a try.

Thanks again to all who have replied. I'm learning quite a bit from my failure!

 

It's 70 water / 30 Alcohol. (90/10 works well enough for me)

 

 

...I have a similar issue making flapjacks - I can never remember the recipe, it's always far too watery. My "LAZY" way out is to just put some more flour in. It then becomes very lumpy so I have to spend considerable time getting the lumps out. It all works out sort of fine in the end and I get away with it. I guess I should try to remember the proper recipe for next time, but I never can. Afterall it's not pyrotechnics, it's only flapjacks.

 

What's a flapjack?

 

That's bloody typical :) I only said "flapjacks" because I was sure I would be asked what pancakes were!! :blink:

 

Jokes aside, the point I was trying to get at with my little pancake analogy was that it's best to try to solve the issue and learn, rather than just a quick fix. With pyrotecnics, more important - with pancakes, not so.

 

My area of expertise is with sugar rockets, so it's good to see that Leatherlips is getting some great advice with the bp variety.

 

Cheers.

Edited by stix
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  • 2 weeks later...

Well, I took some of the "bad" fuel, and put it in a mill for a few hours. With this I built one engine. I then took some Goex 4f and built another motor. Then I created some hotter (75 15 10) granulated/dried and built another motor.

 

I tried two of them today (Old fuel ball milled and Goex). The old fuel motor I just set between some bricks and tried to light it as I would for a rocket (I used some vulcan quick match,with about 3 inches exposed and inserted up in the motor). This failed to light the motor, I then took some of the white paper fast fuse(the one with several gray strands inside) and inserted that up in the motor (with the grey fuse exposed on the interior of the motor). This failed to light. I then took some green visco and inserted in up in the motor. This finally was able to ignite the motor (and the thrust seemed decent though I have no idea how it would have flown).

I then tried the Goex rocket motor and with the Vulcan quick match it immediately turned into a big salute. (very loud salute!)

I have not yet tried the hotter BP motor, but I'll update here when I do.

 

What is the right way to fuse the motor? I read somewhere that it's best to light the motor nearer to the top inside. With that older fuel I assume there was just something wrong with it that it didn't light easily?

 

Thanks!

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Hello all. I'd like to clarify a couple of things. Ned is fond of granulating his milled BP with denatured alcohol. This (milled) granulated product is used by him for rocket propellant and lift. When I attempted to duplicate his process- many times, AND with different alcohols, I got very poor granulation and plenty of dust. My version was inconveniently dusty for rockets and useless for lift.

 

The whole idea of granulating BP with alcohol is to avoid weakening the powder with binder, and to avoid dissolving the nitrate. My personal opinion is that water may slow down fast BP and may speed up slow BP. Pretty wishy-washy, huh? Anyhow, I proved that rubbing alcohol does not affect the speed of BP, and makes better grains than straight alcohol.

 

In my previous pyro life I followed the popular wisdom that said decent BP cannot be made without milling the 3 components together. The popular wisdom also says nozzleless rockets require hot ball-milled BP. In my rocket experiments I constantly sought to make faster and faster powders, ultimately lifting a 6" ball shell on a 1# rocket on standard BP tooling. I had to use a nozzle though. AND, it did not display at 'normal' height either. But no embers hit the ground.

 

Once a generous fellow pyro gave me some 5/16" SS balls, I was able to make ERC charcoal perform better than I had ever seen before. I will admit that with my first batch I ALSO milled the BP with the SS balls. There is no lecture necessary. I did it once for comparative purposes. I don't recommend it either. What I found was that the efficient milling of the charcoal used in BP is critical to making fast BP.

 

Along comes a newbie pyro asking for my advice. He wanted to fly a 4" ball shell on a 3# nozzleless rocket made with screen-mixed BP. We can niggle over terminology, but: the nitrate was pre-milled, and the charcoal he used was commercial airfloat. I did not believe it would work. It did. His rocket was still coasting upward when the shell displayed.

 

No problem, I thought. I'll just reconsider everything I thought I knew about rockets and go from there, just as soon as my ego heals enough to put any weight on it. I did a couple of tests with my Acme test stand. Finally, I decided to use my well-milled ERC charcoal and milled potassium nitrate to make screen-mixed rocket propellant. So I ran my 75-15-10 mix through a 100 mesh screen 3 times- laborious, I know. But no ball-milling complete BP! I granulated it with rubbing alcohol. I did lubricate it with 2% wax additionally, but don't get hung up on that minor point. It is not critical to success, and it does weaken the powder somewhat.

 

Armed with this new knowledge and a couple of test results, I pressed a 1# NOZZLELESS rocket on a looong BP spindle- 6 1/2" on the taper, like TR uses. I put a couple of pinches of FeTi on the propellant above the spindle tip for tail. I threw together a shabby 5" shell with strapping tape and stuck 'er on the motor. Success!

Here it is:

 

https://www.youtube.com/watch?v=ZrgOfw08cTQ

 

The most important thing I take away from all this is that the fineness of the charcoal is an often over-looked factor in determining the potential speed of BP. Blade-milling does not produce all airfloat- nowhere near. -100 mesh is NOT airfloat. Milling charcoal alone with lead causes extreme wear on the media and the charcoal is contaminated with GRAMS of lead per batch. I believe the key to the initial success of the newbie that started all this was the fineness of his commercial airfloat. I believe my piggy-back success was the use of ERC charcoal, well-milled with the most efficient media I have used yet. This leads me to believe that one very important aspect of milling BP is the more efficient milling of the charcoal. The fluffy nature of charcoal milled alone causes it to easily evade the media, hampering milling. The use of smaller media gives it less places to hide. The use of non-wearing media keeps it undiluted. If your charcoal is milled with the saltpetre and sulfur, it is prevented from escaping the crushing effects of the media. This is a far easier (and more dangerous) way to do things. That's why everybody does it. Because of the ease, not the danger! The danger can be minimized.

 

All this blah, blah, blah is not to convince anyone to change any of their methods. It is simply to report things that I have discovered in my pyro journey. 10 years from now I will probably look back and think what a tyro pyro I am (was) today:)

 

I guess the bullet points of all this rambling would be:

-rubbing alcohol won't wreck your BP

-good nozzleless rockets can be made without milling complete BP

 

Forster

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  • 2 weeks later...
My rocket flew about 50 meter but according to propellent it should fly about 800 meters but after flying 50 meter my nozzle blew out of rocket my nozzle was made up of an epoxy known as m-seal what could be reasons and how could I improve it
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what could be reasons and how could I improve it

Your using improper materials, and flawed technique. The solution would be educating yourself, and then re-try what you want to achieve, with the new knowledge as a foundation.

 

Were doing mostly pyrotechnics here. If you want to look at hobby rocketry, there are other forums that might be more suited, but i think you'll get about the same response to the question.

B!

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In that case... Fix the problem?

 

A blow out is exactly "rocket science" to fix. If you know how to, go do it. If you don't, read post 37.

B!

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Reduce the length of the core and try again. Stuff some dryer lint into the core (a small amount) to retard the burn.

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Today I failed to launch my rocket it didn't even lift off the ground and started burning there I think my nozzle was too big it was of 12 mm in diameter and combustion chamber of 3 cm fuel was kno3 core burnburning rocket core of 6 cm in length and 12 mm in diameter
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My rocket flew about 50 meter but according to propellent it should fly about 800 meters but after flying 50 meter my nozzle blew out of rocket my nozzle was made up of an epoxy known as m-seal what could be reasons and how could I improve it

 

Mr thanks for your rreply but I am will aware of sugar rocket and I have wwell knowledge in rocketry

 

I just figured out the problem IIt was excess amount pressure so accidently nozzle blew out

 

Today I failed to launch my rocket it didn't even lift off the ground and started burning there I think my nozzle was too big it was of 12 mm in diameter and combustion chamber of 3 cm fuel was kno3 core burnburning rocket core of 6 cm in length and 12 mm in diameter

 

 

Your using improper materials, and flawed technique. The solution would be educating yourself, and then re-try what you want to achieve, with the new knowledge as a foundation.

 

B!

 

First the nozzle blows out (over-pressurization?), then the rocket just sits there (under-pressurization?) ???. When testing rocket motors it is important to be CONSISTENT with your materials and methods. Then change just ONE thing and re-evaluate from there. Starting with small motors would be best.

 

First you say you have "well knowledge" in rocketry, and then you insult people by ignoring good advice. Then you just do what you want anyway, fail again, and come back here asking the same bloody questions!!!

 

You obviously don't have the basics, so I for one won't be giving you any advice other than what's already written above (and the attachment) - for the simple reason that you ignore advice, you could hurt yourself, or worse, hurt others.

 

This is the first book you may want to look at (attached cover)

post-19349-0-67970800-1427503973_thumb.png

 

Obviously that book is not real, but there is a message there. Seriously - you should do some proper research first. There is plenty of good info out there, if you get stuck then come back here and ask some informed questions.

Edited by stix
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guys you should read the all the theory in richard nakka's site

 

+1

 

Richard Nakka's site was my main resource when I started out making sugar rockets. I wouldn't say it's necessary to "read all the theory" to make a successful rcandy motor. I prefer practical application with a sound knowledge base which includes basic theory.

 

These are also great references:

http://www.thefintels.com/aer/rocketindex.htm

http://jamesyawn.net/candyrocket/

 

Also posted on this forum in the last few months:

http://www.amateurpyro.com/forums/topic/10059-rcandy-not-working-properly/

http://www.amateurpyro.com/forums/topic/10324-substitute-for-fuse/

 

There are many threads on this forum regarding rcandy/sugar rockets. Theory is one thing, but you can learn a lot from other people's practical experiences. - Did you ever bother to search here on these forums and do some reading?

Edited by stix
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Hey stix - Put me down for a few copies of that book when you get it finished. I know a few Darwin award types that would find it much more useful than a fresh pound-'0-Perch :lol:

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Hey stix - Put me down for a few copies of that book when you get it finished. I know a few Darwin award types that would find it much more useful than a fresh pound-'0-Perch :lol:

 

No probs Shunt. Hardback, paperback, pdf or kindle?

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Hardback, with signature if you will... I hear those have the best resale value as time goes on :D

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Consistent increments of fuel and consistent pressure to each increments is vital to rocket building. Before trying to lift something with a motor I make sure that my fuel fits my tool. Then the process of finding out how much my motors can lift. If your a serious about being a rocket builder I would seriously invest in pressure gauge. I've had more CATOS with a Arbor press with no gauge verses one with a gauge!

 

I'm not sure the size of your tool and tubes but if it's standard then you should be able to find the answers in this subject on this forum. I know youtube videos make shit seem so easy to do.

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Consistent increments of fuel and consistent pressure to each increments is vital to rocket building. Before trying to lift something with a motor I make sure that my fuel fits my tool. Then the process of finding out how much my motors can lift. If your a serious about being a rocket builder I would seriously invest in pressure gauge. I've had more CATOS with a Arbor press with no gauge verses one with a gauge!

 

I'm not sure the size of your tool and tubes but if it's standard then you should be able to find the answers in this subject on this forum. I know youtube videos make shit seem so easy to do.

 

+1

 

Good to see that this thread is back on topic. I keep forgetting that the original poster Leatherlips was asking about bp rockets - there has been a similar thread regarding similar issues. So I apologise to Lips for my part in this thread going a bit askew.

 

Yes, agreed that youtube vids can tend to make things look far too easy.

 

Leatherlips, How are you going with this? It might be best to start again with a new batch of fuel.

 

Cheers.

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