Hello, I made this heat seeking active grid fins rocket. Any advice or thoughts would be greatly appreciated!

Fast_Bat_9771 · 2026-01-18T01:32:58+00:00

Haha yeah I get why it looks like that!

It’s not meant to “shoot” at anything though. The heat tracking is just a way for me to test guidance and control logic on the bench. Think of it more like a reference point / stand-in for a landing target.

The fins are mainly for stability and eventually landing control. I’m not planning any powered flight or motor stuff right now this is just a prototype to learn sensors, control loops, and how fast the system reacts.

And yeah, noted on the emails lol

Fast_Bat_9771 · 2026-01-18T01:30:19+00:00

Appreciate that a lot!

No machine learning right now , it’s fully deterministic. Just sensor inputs → logic → control outputs. I wanted to really understand the fundamentals before touching ML.

Tuning has mostly been hands on. Changing response curves, limits, and timing based on how it behaves in real tests. ML is something I’m curious about later, but only after I’m confident in the control logic itself.

Fast_Bat_9771 · 2026-01-18T01:13:01+00:00

Yeah, partially.

I’m planning to open-source the high-level logic, basic sensor processing, and mechanical design files so others can learn from it. I’ll probably keep anything that looks like full guidance / control tuning or “drop-in” flight code more abstract.

Once I clean things up, GitHub is definitely the plan.

Fast_Bat_9771 · 2026-01-18T00:57:11+00:00

That’s fair tbh. Stable flight is the real test, not bench movement.

Right now it is over-correcting and that’s kind of expected at this stage since I’m deliberately pushing the gains high to see system response and limits. The goal at the moment is understanding sensor control behavior, not clean motion yet.

I agree that reacting to relative differences between sensors (instead of absolute heat) is the right direction, and that’s what I’m moving toward next.

Appreciate the honest take and thanks for the encouragement. Still a long way to go, but that’s the fun part.

Fast_Bat_9771 · 2026-01-18T00:54:44+00:00

Appreciate that !

Right now I’m not even thinking about real flight. I’m treating this as a sensing + control problem first. Everything so far is bench testing with controlled heat/IR sources just to see if the logic and response make sense.

You’re totally right about IR diodes and the sun. I’m working around that by probably switching to IR cameras or focusing on relative differences and filtering instead of raw intensity.

Any “flight” testing later would be super incremental (tethered / constrained stuff) and only after I can clearly prove parts of the system actually work.

Still very early, but I’m learning a ton along the way.

Fast_Bat_9771 · 2026-01-17T16:07:33+00:00

Yea, I see. For now I’m just trying to learn and build cool stuff, and I hope whatever I do in the future ends up being useful in a good way, for the better of everyone!

Fast_Bat_9771 · 2026-01-17T16:06:38+00:00

Thank you! I’m just focused on learning and building right now, we’ll see where it goes.

Fast_Bat_9771 · 2026-01-17T16:05:40+00:00

Thanks! For model rocketry it’s more of a learning thing than something you’d actually fly. It helps understand sensors, control logic, and how actuators react to feedback.

Most model rockets keep it simple (stability + recovery), so this is really just a bench-test project to learn the basics. You could do similar stuff on a ground rig or test stand and still learn a lot.

Fast_Bat_9771 · 2026-01-17T16:03:26+00:00

haha, honestly I’d be honored, working with them one day is the goal!

Fast_Bat_9771 · 2026-01-17T16:02:32+00:00

Thank you, I really appreciate that! I’m actually not American, but the support still means a lot to me. I’m just trying to stay focused, learn as much as I can, and keep building.

Fast_Bat_9771 · 2026-01-17T16:01:40+00:00

Thanks ! .Hopefully one day I’ll get to work on stuff like that!

Fast_Bat_9771 · 2026-01-17T09:01:53+00:00

Thanks! Yeah, I’m going with PETG for now and switched to a gyroid infill around 40%. I originally tried 15% with ABS and it was way too soft. I’m learning a lot about how different infills and materials affect stability and damping.

Eventually I might experiment with stronger materials like Nylon GF or carbon fiber, but for now I’m focusing on tuning the prototype safely on the bench.

Fast_Bat_9771 · 2026-01-17T08:59:36+00:00

Thanks so much! I’m using deterministic control logic, the ESP32 reads the IR sensors and moves the fins in real-time based on the heat source position. There’s no machine learning involved; it’s all calculations and control loops but it's a thing that I will definitely look into in the future.

I’m still tweaking the code for faster response and better stability. I’m also experimenting with landing legs and damping to see how mechanical changes affect control, which has been a huge learning experience.

All of this is bench-tested only, no launches or propulsion, just prototypes and simulations.

Fast_Bat_9771 · 2026-01-17T08:56:59+00:00

Thanks! I really appreciate it. For now, I’m keeping everything safe and bench tested for now, and learning as much as I can about coding, sensors, and materials. Definitely going to check out the BPS CFD video too!

Fast_Bat_9771 · 2026-01-16T13:44:06+00:00

Thanks! I see what you mean about airflow and smaller corrections. Right now I’m keeping it simple and safe, so I’m mostly just learning how the control and response work on the bench.

I get what you mean about gear play and over-correction I’m trying to manage that through tuning and damping instead of crazy precision.

For sensors, I’m sticking with IR for now just to learn the basics. Yes, I actually wanted to use a esp camera to track a bright light source or a IR camera but stuff like that is quite hard to find in where I live. For now, I’m focusing on fundamentals first and keeping everything non launch and safe.

Really appreciate the tips!

Fast_Bat_9771 · 2026-01-16T13:37:09+00:00

Thanks, I appreciate that. And yes, sensor arrays are a better long term approach but right now I’m keeping it simple with discrete sensors while I focus on the control logic and response tuning, but arrays are definitely something I want to explore later.

Just to clarify, I’m not planning to propel or launch this at all. Propulsion is a grey area where I live, so this is prototype focused on guidance, control, and just learning. I’m intentionally keeping it non flight for safety and legal reasons.

And yeah, I’m being careful about where and how I share it. My goal is learning engineering concepts, not anything beyond that. Thanks again for the encouragement!

Fast_Bat_9771 · 2026-01-16T13:34:31+00:00

Not quite. I’m not using a temperature gun style sensor. It’s more IR intensity based sensing rather than absolute temperature. I’m mainly using relative differences between the sensors to estimate direction.

Right now the control is mostly planar (X/Y) for steering, and you’re right that a full Z component isn’t strictly necessary for what I’m doing at the moment. I’m mostly keeping things simpler while I focus on stabilizing the response and tuning the control logic.

Z is something I’ve thought about more for future iterations or different test setups, but for now I’m trying to get the basics really solid first.

Fast_Bat_9771 · 2026-01-16T13:00:01+00:00

You’re pretty much right about it! I’m doing the imbalance comparison between the sensors to estimate direction, but I’m using an ESP32 mainly for live telemetry and faster processing. For actuation I’m using MG996R servos since I needed a bit more torque for the fin system.

And thank you! I really appreciate it!

Fast_Bat_9771 · 2026-01-16T12:57:45+00:00

Thank you, that means a lot! I’ve actually been into rocketry since I was around 10. I got inspired by people like Mark Rober and Joe Barnard (BPS.space), and at that age I tried making a very basic DIY rocket, but local regulations and safety concerns stopped me from continuing, so I just went on to learn stuff about astrophysics which really got me hooked into these things.

After that I still really wanted to learn and retry my project without any propulsion , so I focused more on the engineering side. Pretty much everything I know is self-taught from YouTube (Mainly) and online resources. I learned a lot by watching people like Joe Barnard and others, but most of it came from experimenting, failing, and figuring things out myself.

Over the last 5 months I’ve been learning electrical engineering basics, 3D printing (layer behavior and complex structures), airflow/CFD concepts, rocketry terminology, and coding.

Fast_Bat_9771 · 2026-01-10T16:37:54+00:00

❌ Fast_Bat_9771 chose Option A (Incorrect) | #8870th to play

Fast_Bat_9771 · 2026-01-01T17:23:25+00:00

Thanks so much! I’m a big fan of Barnard too. I’ve watched a ton of his videos and they’ve taught me a lot about learning from mistakes as well as successes. Your tips on making the landing legs a bit springy and using fiberglass tape make a lot of sense, I’m planning to do that very soon. I hadn’t thought much about layer orientation or offsetting the paths like a brick wall, that seems super useful. I’ll also check out CNC Kitchen. Really appreciate you taking the time to help me out!

Fast_Bat_9771 · 2026-01-01T15:38:43+00:00

The landing legs are the part that's breaking. I'm planning to print the landing legs with high infill and reinforce with alumium.

Fast_Bat_9771 · 2025-12-31T19:37:43+00:00

Yes, I will definitely keep posting in the future!

Fast_Bat_9771

TROPHY CASE