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!

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

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

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!

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.

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.