Long Burning (7+ sec) PVC Solid rocket motor, around 8-12N thrust?

[Jonathan Hamilton-Meikle]

Hi,

I'm working on a project, to make a self landing hobby rocket, but with a solid rocket motor. I would like it to be a slow burnin one preferably with a stable thrust througout the burn time of it.
I want to be able to make it at home (obviously I would order ingreedients), so that I can experiment with it, but the main reason I want to be able to make the motor is that I need 3 little motors with a combined thrust*time equal to 1 big (3x bigger) motor. I also need to be able to add time delays to the main big motor.
Any help with ingreedients and proporions would be much appreciated.

Thank you so much,
Jonathan H-M.

 

[Ben Martin]

This belongs in the restricted forum which requires an L1 certification as we do not discuss ingredients or formulas on the public forum. I would highly recommend finding a local club, getting started in model rocketry (Estes, etc), and learning the safety procedures that these organizations follow. It's amazing what you can learn from attending club launches and talking to people who have a lot of experience in rocketry. What you are trying to do is very dangerous especially for someone who does not have experience in rocketry, this project is something that people who have a TRA L2 certification + experience should attempt in order to ensure your safety and others. Please do not do anything irresponsible, research about clubs in your area and then come back to this proposal in a while. By then you will realize that it is was not a smart idea and that the experience you gained from others working on starter rocketry has set you on the right course. Rocketry is a fun hobby but we are serious when it comes to safety and incidents caused by those on the wrong path harm the public's view on model rocketry.

An option once you become more experienced is BPS.space who make gimbaling motor mounts for model rocketry. Joe Barnard is attempting to make self landing hobby rockets, I highly recommend checking him out on Youtube and learning about it. I do not see a reason to create your own motors, especially without experience or guidance while there are excellent commercial options out there.

 

[Jonathan Hamilton-Meikle]

Thanks for your advice, I really appreciate it!

 

[Ben Martin]

Thanks for your advice, I really appreciate it!

No problem, if you have any additional questions feel free to message me and I'll be more than willing to help you out. I was in your same situation with the same idea in my mind when I was your age. I decided to join a local club to gain experience and I have loved the hobby ever since. Motor making is a dangerous art if not done properly, hence why a lot of prior experience is required. For a project of this magnitude small rockets with commercial engines is the way to go as its safer and best of all, cheaper! To restate, feel free to contact me and I hope you join the hobby soon.

 

[cwbullet]

I decided to join a local club to gain experience

I would have to echo this. I suggest finding a club and mentor in your local area. The club and mentor can provide you will tips and tricks that often are lost in the forum. As you progress to motor making and upper-level skills, they can teach safety precautions to prevent injury and property damage. These little tips will help you reduce risk and maintain safety will still having fun launching rockets.

 

[cbrarick]

to echo all of that: great advice but there's one more glitch: you can't use PVC motor cases in a Tripoli launch (and there's no EX in NAR). The reason? Failure is mostly shatter, and you can't x-ray someone for PVC fragments.

 

[Ben Martin]

to echo all of that: great advice but there's one more glitch: you can't use PVC motor cases in a Tripoli launch (and there's no EX in NAR). The reason? Failure is mostly shatter, and you can't x-ray someone for PVC fragments.

Forgot to mention this in my post, thanks for adding it. The issue is that many of the "build your own model rocket motors" on YouTube use PVC as it's cheap. This inflicts the mindset on kids that is is fine to use which is very dangerous. Just another reason to learn the proper methods of rocket motor creation from people at a local club after gaining experience.

 

[cwbullet]

to echo all of that: great advice but there's one more glitch: you can't use PVC motor cases in a Tripoli launch (and there's no EX in NAR). The reason? Failure is mostly shatter, and you can't x-ray someone for PVC fragments.

I have to agree. That is why I hinted at getting a mentor:

I would have to echo this. I suggest finding a club and mentor in your local area. The club and mentor can provide you will tips and tricks that often are lost in the forum. As you progress to motor making and upper-level skills, they can teach safety precautions to prevent injury and property damage. These little tips will help you reduce risk and maintain safety will still having fun launching rockets.

I guess I should be more direct. 1. GET A MENTOR. 2. Don't use PVC in your motor cases.

You appear to be in Hungary. I am not so sure there are any TRA clubs there. Look at your local laws and see if you can organize a club. Schools and youth groups are a great place to start.

 

[BDB]

You might want to look into long burning commercial motors, like the Apogee F10 or the Aerotech G8, G11 or G12. I think the F10 sounds like exactly what you are looking for. You can search for the trust curve for each of these motors on www.thrustcurve.org.