Rocket candy help

[mrgordyp]

Ok guy, today is my first day joining this forum and I need some input. I have recently made two batches of rocket candy, which in my opinion works well, however Im not the best with the math to figure out if my rocket will fly. So, i will put it like this and maybe someone can help.

The rocket i want to fly weighs 1/2 lbs, engine loaded and ready to fly. The thrust on my first engine test was 4lbs, but only for a second i guess the fuel was not packed correctly. The thrust on my second engine test was much better at about 6 1/2 lbs for 3-4 seconds. Shown here

https://www.youtube.com/watch?v=sWdrn...e_gdata_player

My question is, will my rocket leave the pad, and how far could i expect it to go assuming my next engine works just like the first????

 

[chadrog]

Video does not exist? Welcome to the forum, by the way.

 

[mrgordyp]

[video=youtube;sWdrnarzlhY]https://www.youtube.com/watch?v=sWdrnarzlhY&feature=youtube_gdata_player[/video] I hope the link works If not my youtube channel name is Mrgordyp

 

[cavecentral]

You might want to try an electronic ignition system and put some safe distance between yourself and that thing.

You probaby should find a club and fly with some store bought motors first. If you understand them and how rockets fly, you will understand yours as well.

If you are using PVC and you are that close, you are asking for trouble.

Take a few steps back before stepping forward.

 

[mrgordyp]

there are no clubs around here where i am, and i have used many store bought rockets and motors... a store bought igniton will not get me farther than where i was standing today, what you dont see in the video is me behind a concrete wall. now with that said ... any help to my question?

 

[cavecentral]

I never used RCandy, so no.

 

[Aksrockets]

Read the forum rules. We arn't allowed to talk much about EX rocketry.

A 'store bought' ignition system give you the advantage to call of the ignition at any point. Once a fuse is lit, it's lit. Where are you located? I bet we could find a club near you.

For altitude estimations, download Openrocket.

-Alex

 

[mrgordyp]

aksrockets... thanks for showing me the program, and the info. i guess this forum is not the place for me.. im looking to do this on my own (without store bought things), ive built the rocket from scratch and i have the knowledge to make my own ignition system (electric) when i get to that point.. right now im just trying to figure out if the fuel is enough to get my rocket in the air. Thanks everyone who replied.

 

[tmacklin]

aksrockets... thanks for showing me the program, and the info. i guess this forum is not the place for me.. im looking to do this on my own (without store bought things), ive built the rocket from scratch and i have the knowledge to make my own ignition system (electric) when i get to that point.. right now im just trying to figure out if the fuel is enough to get my rocket in the air. Thanks everyone who replied.

If you can't find it here, try this: https://www.nakka-rocketry.net/ Stay safe.

 

[cbrarick]

Dude:

The forum is the right place for you. The real problem is that you aren't ready to do what you're doing. In order to fly research motors legally, you need:

1. To belong to Tripoli (tripoli.org)
2. Be high power level 2 certified
3. Comply with the research safety code https://www.tripoli.org/LinkClick.aspx?fileticket=dwhtBHGL9Zc=&tabid=325
4. Have a FAA waiver (by definition, all EX is high power)
5. Have landowner permission to fly there
6. In some cases, have fire marshall permission to fly there
7. Comply with NFPA 1127

Joining a club will get many of these things done for you automatically. If you choose to do this on your own, then you need to comply with all of the things above, plus whatever state and local regulations you might have to deal with. Failure to comply puts you outside the law, subject to fines and arrest as well as liability for anything that could go wrong (blow something up & hurt someone, hit a car, building or person, start a fire, scare the locals, ect) and the worse part is that you alone will have to pay because none of your insurances will pay for illegal acts. AND you will give the rest of us another black eye, even though we didn't participate in your event and have advised you to "do it right."

So please join a club, do it right and stay safe! EX can be a lot of fun once you get past the initial learning curve.

Once you are certified high power, you can get access to the EX section of trf, which is where we can discuss what went right and wrong in your video - that's the rules of the forum!

best of luck

rick

 

[Voxels]

What cbrarik said.

 

[MCS]

Dude:

The forum is the right place for you. The real problem is that you aren't ready to do what you're doing. In order to fly research motors legally, you need:

1. To belong to Tripoli (tripoli.org)
2. Be high power level 2 certified
3. Comply with the research safety code https://www.tripoli.org/LinkClick.aspx?fileticket=dwhtBHGL9Zc=&tabid=325
{snip}

Hmm... last I checked Tripoli is a club not a regulatory agency. There is no requirement to be involved with Tripoli or follow their safety recomendations.

The main advantage of a club is the ability to share resources and ideas.
What part of the country/world are you located??

https://www.thefintels.com/aer/propellants.htm
https://www.sugarshot.org
https://www.nakka-rocketry.net
https://www.amazon.com/dp/0983523029/?tag=skimlinks_replacement-20


-->MCS

.

 

[falingtrea]

Hmm... last I checked Tripoli is a club not a regulatory agency. There is no requirement to be involved with Tripoli or follow their safety recomendations.

The main advantage of a club is the ability to share resources and ideas.
What part of the country/world are you located??
-->MCS

That may be true, but in many places it is an uncomplicated way to do what the OP is doing, legally. Everything depends on location, location, location. At a minimum, in the US the OP would at least need:

4. Have a FAA waiver (by definition, all EX is high power)
5. Have landowner permission to fly there (in order to even get a FAA Waiver)
6. In some cases, have fire marshall permission to fly period

And if the governing body at the launch area has adopted NFPA as regulations, NFPA1127 and maybe even NFPA1125.

 

[r1dermon]

You may be interested in joining the PGI and hooking up with the rocket guys over there. There is no regulation that says Rcandy is EX or requires a permit or anything else. Im not sure but I don't think Rcandy is on the atf explosive materials list.

Just for precautions sake however, use convolute paper tubing which can be purchased from a variety of online retailers or even custom made to Your spec. Also use remote electronic ignition. With scab wire you can get yourself back dozens of yards. You may want to pickup a load cell also, and focus on reproducing your results reliably. If your thrust figures are varying by 20-30%, that can lead to some real bad flights. The pyro guys with pgi will have all the necessary permits and insurance to CYA in the event of something going wrong. And your right...this isn't the forum for EX talk, especially when the approach is elementary and unscientific. Good luck.

 

[r1dermon]

In regards to your rocket leaving the pad...is your rocket stable? What's the initial thrust of your motor? The problem is if your motor has enough kick to get your rocket off the pad, but not enough to fly it stable, well, you're going to have a missile on your hands. If you're not in a real big field, I wouldnt fly a homebrew rocket motor in a rocket...its kind of just asking for trouble and could prove unsafe. What are your plans for recovery? How much will your rocket weigh?

 

[dave carver]

https://www.nakka-rocketry.net/

Try there. Richard Nakka is kind of an athority on what you want to do.

 

[Handeman]

Dude:

The forum is the right place for you. The real problem is that you aren't ready to do what you're doing. In order to fly research motors legally, you need:

1. To belong to Tripoli (tripoli.org)
2. Be high power level 2 certified
3. Comply with the research safety code https://www.tripoli.org/LinkClick.aspx?fileticket=dwhtBHGL9Zc=&tabid=325
4. Have a FAA waiver (by definition, all EX is high power)
5. Have landowner permission to fly there
6. In some cases, have fire marshall permission to fly there
7. Comply with NFPA 1127

Joining a club will get many of these things done for you automatically. If you choose to do this on your own, then you need to comply with all of the things above, plus whatever state and local regulations you might have to deal with. Failure to comply puts you outside the law, subject to fines and arrest as well as liability for anything that could go wrong (blow something up & hurt someone, hit a car, building or person, start a fire, scare the locals, ect) and the worse part is that you alone will have to pay because none of your insurances will pay for illegal acts. AND you will give the rest of us another black eye, even though we didn't participate in your event and have advised you to "do it right."

So please join a club, do it right and stay safe! EX can be a lot of fun once you get past the initial learning curve.

Once you are certified high power, you can get access to the EX section of trf, which is where we can discuss what went right and wrong in your video - that's the rules of the forum!

best of luck

rick

Hmm... last I checked Tripoli is a club not a regulatory agency. There is no requirement to be involved with Tripoli or follow their safety recomendations.

The main advantage of a club is the ability to share resources and ideas.
What part of the country/world are you located??

-->MCS

.

You're right MCS. That post was full of misinformation.

1. There is no requirement to join Tripoli or any other club to fly research motors. If you want to fly them at a Tripoli sanctioned and insured launch, then you must join.
2. There is no requirement to be certified to fly any research motor. Anyone can fly research motors. If you want to fly them at a Tripoli sanctioned and insured launch, then you must be certified.
3. The research safety code only applies to Tripoli sanctioned and insured launches.
4. You only need a waiver if the rocket is a Class 2 or higher rocket. It doesn't matter if the motor is High Power or not. A 2 lb rocket with an Aerotech H250G motor is a Class 1 rocket and does not require a waiver.
5. You technically don't need landowner permission to launch a rocket, but you would be trespassing if you enter the property.
6. To fly legally you do have to follow the laws for the AHJ, that could be the state and/or local fire marshal.
7. Not all states adapted the NFPA 1127 so it may or may not apply.

With all that said, it is easiest to legally fly research motors at sanctioned Tripoli launches. There are more rules required like the certifications and safety rules, but the waivers and AHJ issues and GSE are taken care of already.

 

[cbrarick]

Well, you should spend some time reading the guidance for filing your class 2 waiver
https://www.tripoli.org/Motors/FAARulesforRockets/tabid/181/Default.aspx
https://www.nar.org/cabinet/waiverinst.html

Both orginizations state that you should reference the safety codes from their organizations: In fact the NAR one also references the TRA safety code.

There's only a few guys in the FAA who process paperwork for class 2 & 3 rockets. I'm willing to bet that if you used significantly different verbage it would set off all kinds or red flags. Kinda hard to get the waiver then.

NFPA 1127 (2013 edition) https://www.nfpa.org/catalog/services/onlinepreview/online_preview_document.asp?id=112713# requires that motors be used by certified users. Guess how certifies users in America? It's NAR & TRA. I've got the NFPA 1127 from 1995 and it's the exact same. It states that in order to "operate or fly high powered rockets" you must be a certified user. Sure, some states might not be NFPA states, but I bet there aren't many.

Perhaps my wording is a little short on my initial post, but I'm willing to bet the content is on. I think it would be an uphill battle for an individual to find a piece of property where the landowner would allow them to fly rockets however they want (in a state without NFPA adoption as well) then get the FAA waiver. Even if they did, they would not have insurance. Even indy clubs make you be certified before you fly EX. I'm willing to bet it's a stipulation on their insurance. I'll stand by my belief that joining a club and becoming certified is the best way to safely fly while obeying all the rules.

JMHO (feel free to ignore if you don't like it)

rick

 

[cavecentral]

Funny how this thread goes on. Not sure the guy is coming back to read any of it.

 

[bill_s]

The rocket i want to fly weighs 1/2 lbs, engine loaded and ready to fly. The thrust on my first engine test was 4lbs, but only for a second i guess the fuel was not packed correctly. The thrust on my second engine test was much better at about 6 1/2 lbs for 3-4 seconds. Shown here

https://www.youtube.com/watch?v=sWdrn...e_gdata_player

My question is, will my rocket leave the pad, and how far could i expect it to go assuming my next engine works just like the first????

4 or 6.5 pounds is more than .5 pounds, so it's not complex math that it will go ... somewhere. Simulation is *routine* for many of us using commercial motors, especially with scratch-built rockets.

Looks to me the thrust was less than 1 second, though impressively constant over that time. Rough guess E range power. Lots of possible hassle, considering..

If you have a farm or something, you can probably do almost anything, but I suggest flying based on your ground tests, rather than actually flying your motor. Determine the closest commercial motor to what you made and fly that (leave your property) instead. This also simplifies recovery by allowing motor delay and ejection.

 

[Area66]

There's only a few guys in the FAA who process paperwork for class 2 & 3 rockets. I'm willing to bet that if you used significantly different verbage it would set off all kinds or red flags. Kinda hard to get the waiver then.

Agree, Here in Canada I think they are only 1 person to proceed it , in our Quebec club it's the president of the CAR who proceed our waiver, I bet if I call to get a waiver they gone call him to ask if he know me.

Edit: I check they ask few questions like :

- What is the experience of the RSO, his certification level
- Rocket Association sponcering the event
- Liability insurance and the coverage

I don't think a newby will get a waiver here........

 

[rocketsaway]

At 6-1/2lbs thrust for 3 secs w/ 1/2 rocket thats 12:1 ratio. Will go higher than expected.
Heres a simple motor thrust representation
Go here for lb force to newton conversion
Go here for thrust weight ratio , compare to average thrust.
Now go here and here and understand what your're doing. Download SRM.xls at NAKKAs site.
You need to learn math to understand. If you dont, you will get frustrated, hurt yourself, hurt some else. Its not as hard as you think.
Go here for recommended safe distance. Its near the bottom.
Now for the obvious.
Dont lite your motors by hand. Use a remote source w/ very very long wires.
Something like this w/ longer wires.
And strap that scale down so it doesnt fall over.

Watch October Sky movie. There is a very important quote from Elise Hickman to her son Homer Hickman. :grin:

 

[mrgordyp]

Thank for all the replies guys, I am sure most of you assume Im some stupid amature with no idea how dangerous rocket motors can be, this is just not true. This motor was my second one built, so cut me some slack if your not actually gunna help with my question.. I have permission from a land owner with a very large farm. He has agreed to let me do all my testing and launches there. I will be letting the local law enforcment know when I do a launch, and to see if they have any issues with it. Also, when i get the thrust and burn rate im looking for, the rocket will be launched with a electric system that im building now.
So far most of you guys seem like a bunch of know it alls who never started out from the bottom with very few resources. Its sad that you attack and spout off rules and regulations instead of trying to help someone truly interested in this hobby. If this is how most rocketry clubs are, I want no part of it. FYI the reason I am making the KNO3 rockets is because even the larger E,F, and G motors i would like to fly cost $40.00 a motor and thats crazy when you can do a little bit of research like im trying to do now and make your own for a 1/3rd the cost. Again thanks to the ones who are actually trying to help.

 

[CarVac]

Thank for all the replies guys, I am sure most of you assume Im some stupid amature with no idea how dangerous rocket motors can be, this is just not true. This motor was my second one built, so cut me some slack if your not actually gunna help with my question.. I have permission from a land owner with a very large farm. He has agreed to let me do all my testing and launches there. I will be letting the local law enforcment know when I do a launch, and to see if they have any issues with it. Also, when i get the thrust and burn rate im looking for, the rocket will be launched with a electric system that im building now.
So far most of you guys seem like a bunch of know it alls who never started out from the bottom with very few resources. Its sad that you attack and spout off rules and regulations instead of trying to help someone truly interested in this hobby. If this is how most rocketry clubs are, I want no part of it. FYI the reason I am making the KNO3 rockets is because even the larger E,F, and G motors i would like to fly cost $40.00 a motor and thats crazy when you can do a little bit of research like im trying to do now and make your own for a 1/3rd the cost. Again thanks to the ones who are actually trying to help.

Where are you? The US? If you use reloadable motors (buy a $50 reusable case, purchase propellant to fill it with), G motors run from only around 12 dollars to up to around 20 dollars per flight. It's the sweet-spot for fun versus price. https://www.wildmanrocketry.com/ShowProducts.aspx?Class=82&Sub=85&Sub1=87

We are a bunch of know-it-alls who never started out from the bottom, because it's not smart to start from the bottom. I credit you for coming here for advice, but advice is what we're giving you. Rocketry clubs are very interested in protecting themselves, because what we do is often perceived as dangerous and one big reason why we're allowed to exist as a hobby is because of the stringent safety regulations we place upon ourselves. We like being in the news, but never on the front page.

 

[scsager]

... even the larger E,F, and G motors i would like to fly cost $40.00 a motor and thats crazy ....

Hello mrgordyp, and welcome to the forum.

Sorry if some of the responses you received were not what you wanted. Making your own motors can be done. Many folks do it successfully.

Your video was very informative.

Most folks would not use PVC for the motor and would not use a fuse because when the fuse fails and ignites the motor instantly - you don't have time to get to a safe distance. When the motor fails and explodes, PVC shatters into shrapnel - the consequences can be deadly.

Folks here are concerned for your safety. - Really!

I would like to comment on your statement about $40 bucks for a motor being crazy. It's very understandable that you want to save some money. I hear you.

But - I think you have it backwards. $40 bucks for a motor is not crazy, Losing a few fingers or an eye trying to save $40 bucks - that's crazy!

 

[Area66]

FYI the reason I am making the KNO3 rockets is because even the larger E,F, and G motors i would like to fly cost $40.00 a motor and thats crazy when you can do a little bit of research like im trying to do now and make your own for a 1/3rd the cost. Again thanks to the ones who are actually trying to help.

G High-Power Style Reloads cost around 15$ and they are not crapy PVC pipe sugar motors; they come with delay, ejection charge and igniter with them and most important repeatable results. As for help,many on the forum already told you, you have to register to the EX section of the forum ( you need to be US citizen and have certification )

 

[cavecentral]

Glad to see you came back - didn't think you would. E-F commercial motors cane be found online at places like www.hobbylinc.com. Overall, good discounts and service. Cases are reusable. If you are not in a field were losing them is a big issue, you can get many flights out of a case.

I will say your motor looked like it worked well. Not sure if you have a pyro delay and ejection to deploy recover or are using an altimeter. That is a whole other animal to tackle before putting one in a rocket.

Rocketry is tough to do safely will everything made from scratch. Safe distances are your friend if that is your goal. Glad to see you plan on using electronic ignition. I'd test your motors in the same area you are flying them ( away from people, buildings, etc).

 

[tmacklin]

I've been doing build your own things for years, just like Vernon Estes and the late G. Harry Stine did before any clubs or national organizations existed. It's fun to retrace the footprints of such pioneers. Please feel free to PM me for any knowledge I've gained through the years. I'd be happy to share it with you.

I'm going to have Chinese food for dinner. Did you know they invented black powder, the original composite propellant?

 

[samb]

... Did you know they invented black powder, the original composite propellant?

And I've heard that once they get strong enough they might aggressively defend their patent ! :wink:

mrgordyp, good luck and stay safe !

 

[falingtrea]

Thank for all the replies guys, I am sure most of you assume Im some stupid amature with no idea how dangerous rocket motors can be, this is just not true. This motor was my second one built, so cut me some slack if your not actually gunna help with my question.. I have permission from a land owner with a very large farm. He has agreed to let me do all my testing and launches there. I will be letting the local law enforcment know when I do a launch, and to see if they have any issues with it. Also, when i get the thrust and burn rate im looking for, the rocket will be launched with a electric system that im building now.

Doing what you are doing means you need to go through more hoops to be legal and safe. Not only should you talk to local law enforcement, you could also find out from the local fire marshal whether what you are doing is ok without permits. That whole issue with fuses is how little control you have over ignition. That is why electrical launch systems are better, for motor teste as well as launches. Electric ignition also lets you be further away from motor so if something happens, you will be safer. And then there is the question of what happens if something goes wrong and you burn up the farmer's field? If the fire department has to come out to put a fire out, guess who may end up having to pay for that?

So far most of you guys seem like a bunch of know it alls who never started out from the bottom with very few resources. Its sad that you attack and spout off rules and regulations instead of trying to help someone truly interested in this hobby. If this is how most rocketry clubs are, I want no part of it. FYI the reason I am making the KNO3 rockets is because even the larger E,F, and G motors i would like to fly cost $40.00 a motor and thats crazy when you can do a little bit of research like im trying to do now and make your own for a 1/3rd the cost. Again thanks to the ones who are actually trying to help.

Well, If you want to ignore regulations and rules, then you run the risk of getting into more trouble than you would like. Even when you follow all the rules and regulations, there is still a lot more risk in doing it yourself.