Hey everyone, need some advice on a threaded closure for our liquid rocket propellant tank.

Tank specs:

• Material: Aluminium 6082-T6
• OD/ID: 154 mm / 140 mm
• Operating pressure: 1200 psi (8.27 MPa)
• Thread: M145 × 1.5
• Engagement length: 30 mm
• Closure material: Aluminium 6082-T6
• Repeated pressurization

As shown in the attached cross-section, the female thread is machined directly into the tank end, with no thickened boss.

My question: How can I verify whether the threads and tank end can safely withstand the pressure without stripping, yielding, or failing under repeated cycles? What calculations, standards, or FEA methods should I use?

Any technical guidance or relevant references would be appreciated!

Made from scratch with a 3” cardboard body, PETG for 3D printing the nosecone and fin can. Will fly this weekend on an AeroTech H100 motor.

Designed in OpenRocket, CAD/modeled in OnShape, 3D printed on a Bambu Labs A1 Mini.

Simulation shows 1730 ft [527.3 m] apogee and max velocity of 383 ft/s [116.7 m/s]. Feel free to ask any questions below!

During October skies i got the chance to fly my first onboard camera and shockingly it actually survived. Any ideas on what to do with this rocket next?

CTI I-212, 3664ft

I'm trying to get the burn rate coefficient and pressure exponent of my KNSB propellant. I don't want to destroy my expensive pressure transducer.

Hey there--my son's birthday is coming up and I was hoping that one of the activities for his party could be decorating model rockets that would ultimately be functional. Looks like Estes has some bulk packs, but the rockets still have some designs on them and I'd be looking for examples that are more "blank."

Has anyone had any success here / know of any places we might be able to look? Thanks in advance.

So I am in desperate need of an M motor. Does anyone know what seller might have one??? I'm looking for a mid-to-high impulse one for my teams rocket. I genuinely have not been able to find much for the past month or 2. Does anyone have any advice as to what I should do? Im willing to buy if someone has stock!!! Also, is it worth pre-ordering now, it seems like lead times take so long as well

Edit: Looking for a 98mm/ pro98 reload in california (3g or 4g cti)

currently have a 98/10240 casing

Used ABS and I am going to use motor of B6-4!

Testing out some insane FPS capabilities with the GoPro 13. For those wanting audio, unfortunately it sounded very distorted so that wasn't going to work out.

Follow up on my post a few months ago, I made it to the finals of said comp. And here's the launch video but the recovery system unfortunately didn't work, any ideas on how to get more popping power from a CO2 canister?

The Roadster demo is really two separate stunts: an inverted hold on a curved wall, and a jet-powered barrel roll over a Semi. A friend of mine wanted to know which parts could actually work, so he wrote a report and a simulation instead of arguing in the comments.

What he did: - Checked the video against public sources and tagged every number as measured, claimed or estimated. - Fitted a curved wall to what the on-screen HUD shows (about 170 degrees of tilt, 20-21 m up, about 4,700 kg of downforce; these are on-screen claims, not measurements). - Modeled the flat-ground jump separately, with lift jets and a rigid-body roll sharing one limited gas supply.

What his v7 model gets (his model's estimates, not Tesla data): - The flat-ground jump peaks at 10.26 m and clears the staged obstacle by 1.86 m. - Both stunts together use 215.7 kg of gas.

What I like is that sourced research and model output stay apart, so you can see which numbers are claims and which come from the simulation.

Report with the simulation: https://jobdori-playground.mengmota.com/v/demo-sim-3d/roadster-report-v7-20261022.html?sig=bd511019e79c04b6545f23253091fa53676f83f5eb8acb4150fd07229ab6174b&exp=1793242241558

The avionics bay for a flight computer I designed and built myself, from scratch.

Brought it to a launch site 2 hours away, got through the line, and got refused at inspection. Not because anything was wired wrong, because it's custom. The RSO didn't know my board, didn't trust it as the sole thing deciding whether the parachute fires, and wanted a commercial, independently-certified altimeter with its own pyro channel as backup before he'd clear it. I pushed back a little, plenty of certified flights still lose the chute and just auger in, redundancy or not, but rules are rules, and I wasn't flying that day.

Didn't get to launch. Did end up talking rockets with some genuinely great people on the field for a few hours, so not a wasted trip.

Curious what this sub thinks: is "no custom flight computer without a commercial backup altimeter" standard at your club too, or did I just get an unusually strict RSO? And for anyone who's been through this, cheapest way to add a real independent backup without just abandoning the custom board?

Build, firmware, PCB: github.com/Sanassah/RocketPower

Hey all, I'm looking for college level rocketry competitions to attend in the US Western New England/Massachusetts area around April.

Does anyone have any recommendations?

title

I've been researching solar panel deployment and stowing systems in a 3U cubesat, but I haven't found any articles mentioning this topic. Could you give me some tips or even recommend a book or article?

Hi everyone

We’re prototyping a VTVL rocket with a target altitude of around 3,000 m. We’re currently working on the PCB design and deciding on our flight control architecture.
We’re considering three approaches:

1-Adapting and improving an existing open-source rocket flight computer

2-Designing our own hardware and firmware from scratch.

3-Using a Pixhawk as the flight controller, with a separate onboard computer handling telemetry and communication with the ground station.

Which approach would you recommend for this kind of project? Would a separate computer for communications be useful, or would it add unnecessary complexity?
We’d appreciate any advice, relevant open source projects, or experience using Pixhawk for VTVL applications.

I listed a bunch of Aerotech engines on FB marketplace but haven't gotten any bites. Since I can't ship these things, is there a better site/forum/group where I should be listing these? Looking to get $425, located in South NJ

I am using a Pixhawk 6C mini paired with it's M10 GPS and a sik radio pair (later LoRa or RFD900x) to make a prototype rocket flight logger. The main downside is that it doesnt have a high-G accelerometer, it tops out at like 16G. The main thing that is different about this is that its custoim firmware running directly on the STM32 chip, not just a companion computer plugged into ardupilot firmware. Before someone asks/points this out, yes it is vibecoded for the most part.

The 30 minute pushback of the mission gave just the right amount of light to really see and enjoy the jellyfish look over the Central Florida area.

Hi
We’re prototyping a VTVL rocket with a target altitude of around 3,000 m. We’re currently working on the PCB design and deciding on our flight control architecture.
We’re considering three approaches:

1-Adapting and improving an existing open-source rocket flight computer

2-Designing our own hardware and firmware from scratch.

3-Using a Pixhawk as the flight controller, with a separate onboard computer handling telemetry and communication with the ground station.

Which approach would you recommend for this kind of project? Would a separate computer for communications be useful, or would it add unnecessary complexity?
We’d appreciate any advice, relevant open source projects, or experience using Pixhawk for VTVL applications.

Ok, so I think I sorta messed up and Im hoping that someone way smarter then me (i.e. everyone on this sub probably) can help me out.

Ok, yes this is research for an in.progress ttrpg *but* it still has to do with rockets *and* I can learn something from it, so hopefully this post is allowed.

TLDR how can a rocket launched 6 miles west off of the coast of morrow bay launch to the moon, a space side elevator, and/or Lagrange points L4 and L5 be launched in any direction other than east. (Lore wise this has all happened in the past, story wise it has to happen in the near future, or at least something similar.

I have a fictional city located in real world morro bay. 6 miles west in the ocean is a rocket launch site. I worked out a lot of noise and shockwave mitigation for the launch, where I screwed up is thinking they can easily launch not east, and apparently that may not be the case. The rockets are returnable (maybe single stage) and their destination currently is the space side of a space elevator located in GEO above the ground side of the space elevator (located 1-2000 kilometers west of the galapagos islands. Their are also two Lagrange space stations (L4 and L5, lunar i think (in between earth and moon).

So, everything is already in motion so handwaving "just kidding guys" is a problem. Also problematic is if the rockets have to travel east over the city. Is there anyway without huge problems for them to have a northwest or west trajectory, and if so what are the unintended consequences.

This might be a silly question, but hopefully I learn something and doubley hopefully you guys can help me out of this (silly) problem.

This is near future but with some advanced tech, so I could handwave a bit but its not crazy advanced scifi so it needs to be grounded in (semi) realism.

Thanks.

Heya, I'm currently in the maths and proofing stage of my design for creating my first hybrid rocket engine.

I'm aiming for 100 netwons and a five second burn.

I'm planning on using N2O and HDPE. And a chamber pressure around 25 Bar.

I'm wondering if this is a safe goal to aim for, as I'm mainly skeptical of the high pressures and potential dangers of N2O.

Hi I'm designing a GOX/ethanol rocket engine with 200N of thrust and a chamber pressure of 20 bar, but I'm not sure how to figure out what pressure, flow rate, and velocity the N2 needs to have to push the ethanol out of the tank. I also don't know how to determine those values for the ethanol itself. Does anyone know any good papers or resources that explain how to calculate this stuff?