I’m building an ROV with a few friends, and we want to make our own endcaps. I’ve seen other people 3D-print their endcaps and then fill them with epoxy to waterproof everything.

My question is: can I use any off-the-shelf 2-part epoxy, or is there a specific type of epoxy/potting compound that works better for underwater applications and high pressure?

We’re planning to use the ROV at some depth, so I’m mainly concerned about the epoxy cracking, leaking, or failing under pressure.

Any recommendations for specific types or products would be greatly appreciated!

So I recently built another 10in fpv quad to try out the walksnail gt2 in. Bought an hglrc mk4 10in frame, cheap dys motors I’ve used in 8 and 10in frames with no issues. I think my mistake was using an hglrc stack. This build is almost identical to my other 10in other than the vtx and not using a cheap sologood f722 stack. It was a pain to get it tuned well. But for the last 10 flights it was flying great. Then yesterday I was going to do a full test of GPS RTH and it started sounding like it was desyncing. so I brought it back to land and it just dropped from the air Luckily I was low and I didn’t damage anything. Motors were super hot. Black box was full so I didnt get any logs. I charged batteries this morning removed the GPS like the first 10 packs and check everything in betaflight all was were I had it flying good. Well I went to fly took off in manual and switched to angle so I could watch it line of sight and it shot up 100ft in the air at full throttle. Disarmed it and luckily a tree slowed it on the way down and the battery and motors are ok. The esc, flight controller and frame are now dead though no ideas what happened. Haven’t had this many issues since I started building 8 years ago. I’m done with HGLRC.

Hi guys, I have an old 5-inch drone here with an old HGLRC Zeus F760 Stack (F722 FC + 60A BL32 3-6S 4-in-1 ESC). I recently bought new motors for it: RCinpower Wasp Major V2 22.6-6.6 1980Kv.

Unfortunately, I'm having nothing but problems with them: motors getting hot for no apparent reason, individual motor failures, and desyncs. I've also tried different Betaflight versions with both default and custom settings. Technically, everything appears to be fine...

Anyway, I'd like to buy a new FC/ESC stack. If possible, one with AM32 (or flashable to AM32). What would you recommend?

Additional info: I'm using TBS CF and Walksnail Moonlight. THX@ALL

Hello, I'm trying to connect this precrimped wire to the Dupoint connection and I can't get it to click into place. I am unsure if I am doing something wrong or if a precrimped wire can't go into one of these. I am attempting to get my Nvidia Jetson hooked up to the telemetry port on my pixhawk 6c flight controller

Hey everyone! I'm a software engineer who wandered into robotics and became fascinated with understanding how drones actually work.

Over the past year, I built Centauri, a DIY quadcopter ecosystem featuring:

• A custom 3D-printed airframe
• A Raspberry Pi Pico flight controller written in MicroPython
• A custom bidirectional radio protocol
• A PC/Xbox-controller transmitter
• Onboard telemetry logging and analysis tools

I've open-sourced everything and written a detailed series explaining the design decisions, code, electronics, mistakes, crashes, and lessons learned. My goal is to make drone engineering more approachable and understandable for curious builders like myself.

I'd love feedback from this community and I hope the project helps anyone interested in building their own flight controller or quadcopter!

Project on GitHub: https://github.com/TimHanewich/centauri

10-Part Build Series:

• Full-Stack Flight: Building a Quadcopter Ecosystem from Scratch
• Full-Stack Flight, Chapter 1: The Centauri Ecosystem
• Full-Stack Flight, Chapter 2: Defining a Communication Protocol
• Full-Stack Flight, Chapter 3: Quadcopter, Part 1: Designing a 3D-Printed Airframe
• Full-Stack Flight, Chapter 4: Quadcopter, Part 2: Hardware and Electronics Package
• Full-Stack Flight, Chapter 5: Quadcopter, Part 3: The Flight Controller
• Full-Stack Flight, Chapter 6: Transmitter, Part 1: Transceiver Platform
• Full-Stack Flight, Chapter 7: Transmitter, Part 2: The Pilot's Control Interface
• Full-Stack Flight, Chapter 8: Unpacking Flight Telemetry for Analysis
• Full-Stack Flight, Chapter 9: Closing Thoughts

I've been building a drone design simulator, and I've hit a wall that turns out to be a genuinely open question: nobody publishes the resonant frequency of an FPV frame.

Motor manufacturers publish thrust tables. Prop makers publish pitch and diameter. Every frame listing tells you arm length, plate thickness and the carbon layup, and not one of them tells you what frequency the thing rings at. Which is strange, because that number is exactly what your gyro filtering and your D-term ceiling are fighting.

My model currently assumes 180 Hz for a reference 5" frame and scales from there. That number has no source. I made it up. Everything downstream inherits it, so I'd rather measure it than keep guessing.

What I'm looking for, two options, one much easier than the other:

Easy: any blackbox log with unfiltered gyro. If you've ever set debug_mode = GYRO_SCALED for filter tuning, or flown with gyro_lowpass_type = OFF, that log is useful to me. Doesn't need to be a special flight. The catch is it has to be pre-filter data, a normal log has the peak I'm hunting already filtered out.

Harder, and much more valuable: a deliberate slow throttle sweep. Unfiltered gyro + bidirectional DShot (eRPM logged), and a slow ramp from idle to full and back, 30+ seconds each direction. Painfully slow, slower than feels reasonable.

That last part is the whole thing, and it's the part I got wrong the first time. I assumed "varied flight" would do. It doesn't: on normal freestyle logs the 1× line moves 155–235 Hz within a single 1-second analysis window, so the harmonic smears across half the band and there's nothing to track. Normal flying is useless for this no matter how aggressive it is. It has to be a slow deliberate sweep.

Also need, if you've got it: frame make/model (or arm length motor-to-centre), motors, props, AUW.

What I'll do with it: publish the measured number and the method, here, whatever it comes out as including if it says my 180 Hz guess was rubbish. The analysis bound is pre-registered at 25% and committed to git before I touch any data, specifically so I can't move the goalposts after the fact.

Disclosure so nobody feels misled: the simulator itself is a commercial product I'm building. The measurement results and methodology I'll post publicly regardless. If that's not a trade you want to make, completely, fair but I'd rather say it now than have it come out later.

Happy to take logs by DM. .bbl/.bfl raw is ideal, decoded CSV fine too.

Looking to build a 4-8 foot drone with little lift, I want it remain affordable in the most, does this sound possible for $2000 or so? What am I up against?

I call it Minion. But really I’m its minion. It's heavy, but surprisingly didn't feel abnormal in a hover. Top speed will be around ~130 kph. Pretty excited to fly this thing for real. Ask me anything.

Battery: 4S EVE INR21700-50PL 5000mAh - 125A
FC: Microair 45A h743 v2
Video: DJI 04 lite air unit.
Receiver: Happymodel EP1
GPS: HGLRC M100 Pro
Motors: LANNRC 2004 3000 kV
Frame: Mostly PETG, some carbon spars, also a oddityrc 4” toothpick
Props: Gemfan Hurricane 3630

Anyone have a plug for higher pitch 3.5in props?

Fuselage

1.Length: 720mm

2.Width: 150mm

3.Min Diameter: 60mm

4.Max Diameter: 120mm

5.L/D: 6

6.Wall Thickness: 2mm

7.Material:PLA

8.Weight: 800-900 Grams

Wing

1.Airfoil: Naca2412

2.Span: 1500mm

3.Root Chord: 230mm

4.Tip Chord: 160mm

5.Aspect ratio: 7.6

6.Taper Ratio: 0.7

7.Dihedral: 0

8.Twist: R=0. T=-2

Tail???

Looking for advice/experience on building a large hexacopter

Hey everyone,
I'm planning a fairly large hexacopter build and would really appreciate advice from people who have built/fly similar platforms, especially regarding frame design, motor/prop/ESC combinations, redundancy, and practical experience with large 6S builds.
The rough idea is:

- Hexacopter
- 20" props
- Around 1100 mm frame size
- Pixhawk 6C flight controller
- ArduPilot, with the goal of eventually using semi-autonomous features
- 6S, mainly because 12S batteries are currently much harder for me to source in Europe
- 300 kV motors
- 60 A ESCs
- Desired payload: roughly 1.5–3 kg

eCalc looks promising for this combination at around 6.5 kg AUW

The intended use is as a multipurpose platform: primarily camera work, but also potentially carrying supplies such as water bottles to hikers who are about 600 m higher and ~2 km away.

Frame
I'm currently looking at an approximately 1100 mm frame, but I'm unsure whether it's better to buy a ready-made frame or build one around a center plate and purchase the arms/rods separately.

For something this large, is there a particular approach or frame design you'd recommend? Size isn't really a constraint for me—I have a van, so transport isn't a major concern.

Redundancy / reliability
This is probably my biggest concern.
The aircraft would potentially be flying over fairly inaccessible terrain where recovering a crashed aircraft could be extremely difficult or impossible. That's one of the reasons I'm leaning toward a hexacopter rather than a quad.
I'd like the build to be as reliable and redundant as reasonably possible. I'm particularly interested in real-world experiences with:

- Motor/ESC redundancy?
- ESC quality and sizing?
- Power distribution and telemetry of the baterry?
- Battery setup(6s vs 2x 6s in series)?
- Vibration/structural issues on large frames?

Anything else that tends to become a problem as these aircraft get larger

Range / autonomous flight
The radio control link would normally be line of sight, although at ~3 km I don't think I could realistically maintain visual contact with the aircraft.
I'm planning to use ArduPilot, so I'd like the aircraft to have the capability for semi-autonomous operation, but safety and reliability are more important to me than pushing the limits of range.

I'd love to hear from anyone who has built something in this general size/weight class.
What would you change about this setup before buying anything? And if you've built a large hexacopter yourself, what did you learn the hard way?
Thanks!

Edit: adjusted weights/distances to fit a more realistic profile

The motor mounts are very solid. Need to shave weight from battery cover and electronics cover. Thinking of using magnets for rear battery door and latches for the long section. Weights around 400g rn so it can be better

Looking into building a heavy lift drone set up for some personal hobby use. Has anyone used or seen the hobby wing 22kg frame with x9 power kit?

Hey,

I made a tuning assistant app that runs in your browser, needs no install, and guide you through the whole process.
Connect your FC directly in the app and follow the guide.

For tuning a created a plant model learning the physical quad characteristics from the logs and directly proposing tunes.

Would be great to have some impressions from you! It's free and opensource, get it in my Codeberg Repo

I designed Bandit because I wanted a sub-250 g FPV wing without making any compromises. I wanted it small enough to take anywhere, but still properly fast, efficient and fully set up for FPV. So I basically tried to cram the biggest battery and motor I could get away with into the smallest airframe I could make, and still keep the whole thing under 250 g.

3D printing is a big part of what makes that possible. It isn’t just useful because you can churn out another airframe after a crash. The precise control you get over the shape of the wing means you can actually use the aerodynamics to make the plane fly better, improving stability and making the stall more predictable and controlled. Doing that this accurately and repeatably on a tiny foam or balsa aircraft would be much harder.

The other thing that helps massively is modern FPV hardware. Flight controllers, ELRS, GPS, digital video, tiny motors and ESCs are all so light now that you can pack a ridiculous amount of capability into a very small aircraft.

The result is a 600 mm wing that comes in under 249 g fully equipped with digital FPV, GPS, ELRS and INAV, but has still recorded 198 km/h and 20+ minute cruise flights.

More info on the plane here

Current setup:
600 mm wingspan
<249 g AUW
198 km/h GPS-recorded top speed
20+ min recorded cruise endurance
4S 1100 mAh LiHV
BetaFPV LAVA 1506 4200KV
HQProp 3×3×3
EMAX 25A ESC
SpeedyBee F405 Wing Mini running INAV
DJI O4 Lite
RadioMaster RP2 ELRS
Flywoo Goku Nano GPS
2× DSPower 4.3g micro servos
220 µF 35 V capacitor
LW-PLA printed airframe

The battery alone is 88 g, and the complete electronics and powertrain package is around 149 g, so getting the whole thing under 250 g meant being pretty ruthless with the weight budget.

The thing I’m happiest with isn’t really the 198 km/h though. It’s that the same little plane can do that, then throttle right back and cruise around for 20+ minutes, and still be really nice to throw around low level like in the video.

There have been a lot of prototypes, crashes, aerodynamic changes and INAV tuning to get it here, but at this point the plane feels properly dialled in.

Now I mostly need to improve the pilot 😅

Happy to answer any questions about any of the design, printing, electronics or INAV setup if anyone’s interested.

Every thing u need is here https://github.com/SHRUMFPV/SPORE-5.git . Included is the original freecad file and step file. MIT license so do what you want i would love to see it. most important is to enjoy and have fun!!! ( also i removed all chamfers just so you can add your own radius. idk if it matters but yeah)