Hi all, I've started doing theoretical engine designing based off 50-70% ethanol + GOX bipropellant engine and from what I've calculated the sizing of the engine seems to be really small compared to the thrust generated. I picked 100lbf at 100-200 psi as a design point and it said I needed roughly 1.5, 1, and 1.375 chamber, throat, and exit diameter to generate the 100lbf with my mentioned conditions. Along with a chamber length of 2.5 inches, it seems incredibly tiny for that much force generated. I double checked with RPA against my calculations and they seemed to be roughly the same so I'm just left a little confused. One inaccuracy I feel like I would have failed to model is if my chamber would even have enough volume for that. The propellant flow in far exceeds what the chamber volume is, so I feel like that would greatly diminish what the thrust would be realistically. Not sure however, I would appreciate any advice!

Hi All,

I'm just getting started with rocketry and I have a background in making software. I was looking at making my own flight computer for fun, mostly for telemetry for now. I've seen other projects use an MCU and write its data to an SD card via csv but I'm looking at using an SBC (Milk-v Duo) and a sqlite database as I use it for a few other projects.

Is there any reason i shouldn't use a sqlite database over just a csv?

I want to use an sqlite database due to the strong data continuity built in case there are any interruptions but i haven't seen anyone else do that so far, so I'm just wondering if there's a reason for that.

Thanks!!

I can't get how the screwed the wing to the servo. Can someone help?

Video

Basically as the tilte says, I woudl like some resources to get started learning how to chose the dimensions for a nozzle design. Thanks!

How much does the pressure value vary from the end closure to the converging section of nozzle? And,How does it depend on the type of ignition employed (aft and head ignition)?

I know what dual deployment is- and I know the basic systems I need for it (drogue chute, altimeter, etc.)

But I don't know what SPECIFIC items I need for it. (Like what's an O-ring?)

Can I get an overview on all the parts I need for a dual deployment system and how each one connects with the others?

I offer help in the design and development of electronic and telemetry systems.

Current state of the rocket. I did want to ask if anyone here has experience with streamlined rail guides though. I’ve yet to attach them and I was wondering how y’all put them on and put them on straight. Thanks!

So I'm a rookie at rocketry and I need to figure out fibreglass layouts for our L3 rocket. It has a length of about 200 cms and an outer diameter of about 100 mm reaching to an apogee of about 3kms and a top speed of 1.2 mach. We need to reinforce our PLA fins with fibreglass and epoxy but we cant figure out what kinds of fibreglass. Also, what would be the pros and cons of suing unidirectional or biaxial for the inner layers of the composite and what would be more logistically suitable for the same?

Anyone know of a paper on coax swirl injectors? Mostly looking for papers to estimate the best relative velocity between ox/fuel that a coax swirl injector may operate in when the propellants are both gas.

Hey, I've never used reddit before but I thought Id give this a shot. So our MSU Rocketry team has a Telemetrum v3.0 altimeter and i've been working on powering it up and testing it. The thing is, when I connect it via USB, open the altOS software, and try to configure device. Nothing. We also have a Raven 4 that was fairly easy to get working. Im wondering, do I need a the teledongle ground station? Is a switch required to turn this thing on? etc. My goal is to set it up and get it connected via USB where it is showing real time data.

We are going to participate in INSPACE competition so for that, I have a small doubt on the position of CANSAT, parachute and ejection mechanism. As per guidelines payload should deploy at apogee. The problem is, if I place CANSAT first, then parachute, then ejection mechanism; the ejection mechanism applies pressure on parachute and less pressure will be transmitted to CANSAT. Since parachute is not rigid, it will deform on pressure and this position is not possible right?

So if I fix the payload first, then the ejection mechanism, then parachute, I can eject the payload easily. So for ejection of parachute do I need separate ejection mechanism?

Why did they not develop solid rocket motors? Was it too complex or was liquid/cryogenic fuel better for the Soviets/Russians?

Hey student rocketry team here.
We need data to test our Kalman filter on. If you have any raw accelerometer and barometer data from supersonic sounding rockets we would very much appreciate it if you could send it in the comments or DM it to me.

Thanks

Is RCS Rocket Motor Parts legit?

Website www.rocketmotorparts.com

Hello,

I'm working on my first motor, a 2.5" OD grain motor. I've run all the hand calcs from Nakka and multiple other research papers. I took an exact motor from the Nakka builds and loaded all the parameters into OpenMotor to map the response but I'm not seeing the same results that he shows. Why are the pressure curves so different?

Same fuel type, same grain dimensions, same nozzle dimensions. Pmax is ~300 psi higher and the curve is very different. Any thoughts?

Just trying to confirm the math against a known grain type, dimension, and nozzle before moving onto my own fuel.

https://preview.redd.it/ug10mnqqzcge1.png?width=1152&format=png&auto=webp&s=10038bfab44153dc4677c892255df3b5bc350e6f

https://preview.redd.it/rh95qoqqzcge1.png?width=383&format=png&auto=webp&s=c0f8359a4754266e58e8ef52dfe281c9f00f48ea

Are there resources on the design of injector manifolds? For example, how to route the propellants uniformly and evenly (equations etc.,).

Does somebody here have a copy of finsim?

Would self syntesysed amonium perchlorate with not very high purities work to make apcp roket fuel?

Hello Everyone,

I am in charge of building the radio pcb and the antenna for the rocket. We are using a 433 Mhz with the rocket reaching max 3Km. I can either buy a monopole antenna (ant-410-cw-qw-ds-1841219.pdf) but i don't have space to put it or buy a patch antenna or i can build it. My idea was to have 2 monopole antennas in the nose cone if that make sense. I was thinking of putting copper wires inside the nosecone and maybe that would work? in your expert opinion does this make sense? i can also cover the nose cone with conductive material if that makes sense? i am open to new ideas as well and this is my first time working with antennas or radio let alone building a rocket.

I am completely new to this, and I want to learn on my own. If anyone is knowledgeable about this one, you can drop the sensors you've used before. I would love to read them all. Thank you so much!

Tl:Dr: trying to restart a rocket club at a 4-year school what advice would you give to get it headed on a proper trajectory.

Hey all, I just transferred to a 4-year college and to my dismay they've had a rocket club in the past however about a year ago the guy leading the charge for it graduated and the club fell through the rafters so to say. After asking around I've ran into several people that have expressed an interest if it ever gets going but there isn't anything substantial in place yet.

My main question(s): What would be good goals for a brand new club to aim for?

Advice on things that yall have seen that you would implement or try to do differently.

Resources on where to get supplies and/or where to look for things.

What does a rocket club MUST HAVES list look like.

What is a good way to divide and concour getting the ball rolling.

As for my background, I've launched 2 high powered Rockets in high-school (a mile pound on a J-330 and a transonic on an L-550 respectively) and was on another college's rocket team for a semester helping build their spaceport 15k rocket but as a noobie wasn't allowed Deep in the details for that one. Additionally I have been working on my L-1 cert but its been on the back burner for about a year or so, have the rocket but no motor for it. Not affiliated with either NAR or Tripolli, I do believe there is both reasonably nearby as well as a local rocketry group not affiliated with any school.

I have no idea what all the previous clubs goals were or how far they got. While I was at the previous 4-year we did a joint L-1 build day with the previous club of the new school but that was ~2 years ago.

My ideas so far start small say F-motors just to help people visualize the concepts, and focus on L-1 certs. I'd like the overall goal to be to compete at Spaceport America. But I feel like there are quite a few steps before getting to that point.

I'm not the most experienced but I imagine I've done a little more than most. As with many big projects the part that I hate the most is hammering out is figuring out (as I call them) the "I don't know what I don't know" questions. This post is in hope to work out a few of those and gauge the scale of things.

If you made it this far thank you so much, gonna take it a day at a time and learn as we go, will be grateful for the help.

Hi everyone,

I’m currently working on a project to design a small rocket using composite materials. One of the challenges I’m facing is figuring out the best way to attach the fins to the body of the rocket.

Here’s what I’m looking for:

• The joint should be interchangeable, so I can replace the fins after a crash.
• I’d prefer not to use bolts or slit methods because I want to fully rely on the structural integrity of the composite material itself.

Has anyone tried something similar or have suggestions for joining methods? I’m open to design ideas like adhesives, interlocking designs, or other creative solutions that work well with composites.

Thanks in advance for your help!

https://preview.redd.it/kloxah0t6zfe1.png?width=886&format=png&auto=webp&s=fdcdd3c4645683158d92abac517f629f86a94023

I am asking for a piece like this

Hello, I am someone who got into rocketry a few days ago, I have not made a single rocket yet but I am planning to. I tried to build one a day ago but I then realized, how do I build the body of the rocket? I am a 14 year old boy and do not have access to heavy machinery, lathes, etc. I really need help with how to make a body and nose cones, everything else in learning and is pretty easy to make but for the others idk.. I would love to hear tips or anything that could help me start my journey. I'm thinking of making a YouTube channel where I record my progress and make engineering related videos and right now I'm thinking of starting off with a rocket that's a foot tall that I make completely by myself, I'm also thinking of always making a new model that's half a foot taller than the previous one and adding two features each time. I would appreciate your opinion or tips or a answer to how I could build parts like the body and nose cone.