r/rocketry

Im currently in an area where Tripoli or NAR rocketry teams do not exist but would love to help and collaborate on rocketry projects, hence would it be possible to join a Tripoli team remotely and if so how?

I launched the attached rocket yesterday and it was highly unstable.

The rocket was 3d printed in 2 pieces out of CF filled nylon-12. I have been doing this with low power rockets for some time and have had only success so far.

The rocket went about 30 feet off the pad, lost stability, did doughnuts in the sky and crash landed. The rocket itself was undamaged. Yay CF Nylon.

I'm struggling to figure out why it was unstable. My initial stability was calculated in OR to be 1.32 cal. Since the failure I have worked to improve any inaccuracies between the actual model and the OR simulation. The stability margin has only gone up. I am at a loss.

Any help is greatly appreciated.

Note: This was launched without the altimeter for the first launch. The mass is currently set to 0g to account for this. Also, not shown in the Cad model are 2 external printed clips I used to retain the engine. I have used these in the past and they retained the engine through ejection. I wasn't sure how to simulate them in OR so they are added as 2 small launch lugs.

https://preview.redd.it/mi77onb0ob2h1.jpg?width=4000&format=pjpg&auto=webp&s=1f8929c05bf3ac039f12e13fae446f9cf23478c1

https://cad.onshape.com/documents/618ad92c47b5d1c829025313/w/e7d3c58b1b98f6d5d6a89844/e/e6b10a854a3658d8296e542a?renderMode=0&uiState=6a0de431cd5d88f88ee9bb7e

https://drive.google.com/file/d/1OLfeIEzHW\_s2ktpoVo8z0vFZw-hcU0v8/view?usp=drivesdk

For those with flight data from commercial parachutes, particularly those claiming to have a Cd of 2.2, how closely do these parachutes actually perform compared to how they’re advertised?

Hey everyone,

I’m looking to start researching and eventually building liquid propulsion systems for the rocketry club I work with. We want to build this project completely from scratch, but since liquid rocketry is a massive undertaking, I want to make sure we start on the right foot—especially regarding safety, infrastructure, and proper engineering workflows.

I would love some guidance from the experienced folks here on how to kick off this journey. Specifically:

• Essential Reading/Theory: What are the absolute "must-read" textbooks, papers, or standards for liquid rocket engine design? (Beyond Huzel & Huang and Sutton).
• Propellant Choice: For a first-time club project, what propellant combination is generally recommended for its balance of safety, cost, and complexity? (e.g., LOX/Ethanol, Gaseous Oxygen/Propane?)
• Scale & Testing: Where should a beginner team start? Should we focus on a tiny sub-scale thruster, or build a gas-feed system/cold-flow test rig first?
• Safety & Regulatory: What are the biggest regulatory or safety hurdles we need to prepare for when setting up a test stand?

If your university or club has successfully transitioned into liquids, I’d love to hear about your timeline and what you wish you knew when you first started.

Hi guys I'm passionate about rocketry. After failing 2 attempts on attending a rocket competition, I want to try building a water rocket.

I know the principle, although I don't actually know practically. How I will keep everything together with all the pressure. How to pump air with a bicycle pump how to release it after pumping and how to make a nozzle for it I just don't want to use the mouth of the bottle directly... And so on

Any help will be appreciated :)

I’m flying a mad cow frenzy xl at almost Mach 1 and I’m concerned about fin flutter

Hello , I want to try building and hopefully completing this project of complete diy rocket as much as possible from scratch meaning custom electronics , body and motor , this does seem like a good fun project to me .

I'm currently in the design phase for an engineering project rocket and wanted to get some eyes on my specs before I start cutting materials. The goal is maximum altitude with a fixed propellant mass.

Key Specs:

* Propellant: ~100-130g KNSU DIY MOTOR , Targeting ~40-60Ns impulse.

* Target Weight: Around 350-400g (TOTAL LIFTOFF)

* Stability: Passive aerodynamic (fin-stabilized).

* Recovery: Mechanical piston ejector (servo-latched, elastic-powered). No pyrotechnics.

* Avionics: ESP32 + MPU6050 + Baro + LoRa telemetry + MicroSD logging+ modified camera

My biggest concerns/questions:

* Piston Ejection: Has anyone here successfully transitioned from pyrotechnic charges to mechanical pistons for apogee deployment? Any tips on seal friction vs. ejection speed?

* Telemetry: I’m planning on using LoRa for tracking. Any common pitfalls with vibration-induced resets on the ESP32?

Any other stuff I should be keeping an eye on ?

Thanks

Formatted using ai

Hello,

I am interested in building an rocket model kit. I did it as a kid (even designed my own) but that was more than 12 years ago so consider me a beginner.

I was interested in the Black Brant II model kit but it is classified as advanced by Estes. What does that really mean ? Is it very hard to assemble ?

Thanks in advance

Hi everyone! How are you doing?

I’m currently working on the flight computer responsible for the active control of a rocket’s airbrakes, and this is my first time developing this kind of system. My background is mainly in software engineering, so I still have a lot to learn about rocket aerodynamics and flight behavior.

Right now, my team has only provided me with the drag coefficients for the airbrakes at 0% and 100% deployment. However, I feel that this may not be enough to build a precise control system. They told me the airbrakes are relatively small, so even full deployment would not represent a major risk, but I still think the controller could perform much better if I had aerodynamic data for intermediate deployment percentages as well.

I was wondering if anyone could recommend:

• Resources/books/papers about active airbrake control
• MATLAB or Simulink examples related to rocket control systems
• GitHub repositories with airbrake simulations or flight-control code
• Methods to estimate drag coefficients for intermediate deployment angles
• Common workflows for validating or tuning these systems

My main goal right now is understanding how these systems are usually modeled and simulated before implementing the embedded software.

Any advice would be greatly appreciated. Thanks!

So, I recently built a pressure chamber for a water rocket and I used epoxy glue ( that one where there are those two substances mixing) to glue two bottomless PET flasks together to create a bigger chamber. At 5 bars it exploded and I need some better glue. Which would you recommend to me?

I’ve been looking around for some composite motors (The AeroTech G78-7 specifically) i understand the cost of the motor but SHIPPING? In what world is shipping something less than 8 inches in length and 2 inches in height and weighs less than a pound cost more than $40?? Let alone the $100 that apogee components is charging. I understand the hazmat fee but that’s crazy for how small of a package it is.

Im 14 and am in overland park, NAR wont allow me to launch a rocket without anyone over 18 with atleast a HPR1 cert, so can someone help me with that?

Anyone with a spent G80T and calipers handy? Need nozzle geometry for CAD

Can't find nozzle-end dimensions anywhere — does it protrude past the casing, how much, and what's the OD? Even a photo next to a ruler would be a huge help. Thanks!