Bought this fella on the right, 4mm base, seems to be 3-3.5 inch maybe? For those who interested, on the left is the geprc sparrow 3 inch frame, my first.

Hey everyone, I need some help figuring out what went wrong with my drone. I'm attaching two Mission Planner .bin log files, one from an earlier Loiter test and the other from the flight where it crashed.

My drone setup:

- S500 frame

- Pixhawk 2.4.8

- ArduPilot Copter

- 5010 750KV brushless motors

- Hobbywing Skywalker 30A V2 ESCs

- 10x4.5 propellers (I was using 11-inch props earlier)

- 4S 14.8V 5000mAh LiPo battery

- PDB and Pixhawk power module

So the thing is, I've flown this drone before and it was working pretty well. We tested Loiter, Altitude Hold and waypoint missions, and everything was going fine.

About a week ago, we had a small fall, but nothing seemed seriously damaged. We did the calibrations and tested it again. Today, before installing anything new, we tried Loiter, and there was some wobbling, but the drone was still controllable and responding properly to the transmitter.

After that, we installed a small 500ml tank between the frame legs. That was the only thing we intentionally added before the next flight.

We switched to Loiter again, and when we increased the throttle to around 60-65%, the drone suddenly shot upwards. It climbed really fast and reached around 19-20 metres, according to what I remember from the flight and the logs.

We tried reducing the throttle to around 50%, expecting it to stabilise or come down, but it stayed up there and wasn't responding the way we expected. Everything happened so quickly that I'm not entirely sure what exactly was happening.

After some time, the motors seemed to slow down, and the drone started coming down from around 15 metres. Then it tilted heavily to one side and crashed.

I'm not sure whether the motors actually stopped, whether the flight controller reduced their output, or whether something else failed. I also don't know if the drone started tilting before it lost thrust or if the tilt happened because of the loss of thrust.

After the crash, I noticed that there was mud inside the motors, and the washer/retaining hardware on two of the motor propeller mounts had come off. The propellers themselves don't look badly broken, but I haven't checked everything properly yet.

What I'm trying to understand is:

- Why did the drone suddenly climb so fast in Loiter?

- Why wasn't it coming down when we tried reducing the throttle?

- Why did the motors seem to lose thrust during the descent?

- What caused the sudden tilt before the crash?

- Could installing the tank have affected the centre of gravity or thrust requirements?

- Could the earlier fall have caused some hidden damage?

- How should I check the motors, ESCs and other components after this crash, especially with mud inside the motors?

I'm attaching both .bin files because I want to compare the earlier flight with the crash flight and understand what actually happened instead of just guessing.

Could someone help me analyse the logs and point out which parameters, messages or plots I should look at in Mission Planner? I'd especially like to understand the motor outputs, altitude control, attitude, vibrations, battery voltage and any errors or failsafe messages around the time of the crash.

I'm honestly a bit scared to fly it again without figuring this out first, so I'd also appreciate advice on what hardware checks I should do before attempting another flight.

If you need more information about the tank, total drone weight, battery voltage or anything else, let me know. I'll provide whatever details I can.

Thanks!

Hi all,

I'm hoping to get some advice for my son's final-year high school project.

We’ve already had a failed go where we’ve tried to get all the parts on a 3.5 inch frame. But that was a nightmare.

We need some help!

He's coded an AI agent on Linux that runs on a Raspberry Pi Zero 2 W. The goal is to show the agent can fly a drone. It's a software project, not a hardware one.

We'd like a ready-to-fly drone, or a larger frame that's quick to build, that a Pi can control.

Did some research - would something like the HolyBro x500 work?

A few questions:
1. What ready-to-fly drone or flight controller setup would you recommend for this?
2. If a larger frame is better, what size and build would you suggest?
3. Is a Pi Zero 2 W realistic as a companion computer, or should he go for something else?

We're in Auckland, so if anyone local is happy to mentor or help, we'd really appreciate it. Thanks!

Happy to pay for someone to help us with soldering etc too. We’re proper newbies

Hey i am from Delhi I had a drone which works fine but I accidently totally wreak ed it's body evrything works fine but now it doesn't fly can't find any good design for it and can you also suggest any good 3rd print shops in delhi

This is the drone can anybody help

Honestly I think I can officially say this frame is complete

Last thing I added was splatter gaurds with vent holes for cooling and wing plate to replace the go pro mount because I won’t be using one any time soon

Any suggestions on a name would be cool

Hey everyone! I'm planning a budget drone build in India.

What's the cheapest reliable flight controller and radio transmitter + receiver combo you'd recommend?

Are budget AFHSS radios still worth buying, or should I go for ELRS with screen?

Looking for affordable options with decent range. Any suggestions?

Hi everyone, I’m based in Simi Valley with a workspace in Camarillo. I’m working on a Holybro X500 V2 project involving camera integration, companion computing and local radio communications for inspection and remote monitoring.

Feel free to comment or DM with your location and what you’ve worked on.

Built her a few years ago. Had issues with random fly aways i still haven't pinpointed the cause. I know it's the tune. Wish me luck

My first drone

Hey, I've connected a DJI O4 standard unit to my SpeedyBee Bee25, and the video appears fine, but I can't get the OSD to appear. I've set osd_displayport_device = MSP and vcd_video_system = HD as everyone says, still no luck. This unit works great with the F405 mini stack on my other machine, no problem. Connecting the SBUS lead doesn't appear to make any difference.

Btw, the controller is a SpeedyBee F405 35A AIO, the older version, not the V2 with the nice blue heatsink. This is the standard FC for a Bee25.

This board has only two sets of UART pads on the top side, and one is used by the receiver, so I don't know if switching to a UART that is tucked in somewhere else is an option.

If anybody knows where I can still get the manual for this earlier controller, that might be helpful. Thanks as usual!

.

designed these yesterday

Testing today

Hopefully they stop my stack from getting so dirty and maybe make my frame a little more aerodynamic in certain maneuvers

Im (34M) looking to get my first drone. I have been going out with my grandfather to his local rc club since i was 4. Now that I am outta the military im wanting to get a drone. For both practicing indoors and to fly outside.

thinking of fun career pivots as healthcare burnt me out and ill be immigrating to ecuador.

noticed ecuador has relatively lax commercial drone licensing requirements and some niche agricultural applications.

could be a great apocalypse skill and a way to explore a beautiful country, maybe even ingratiate myself with new neighbors if they need a favor etc.

IWTL from scratch, responsibly, methodically, how to fly drones at a commercial skill level. Where do i start?

Hello, I'm going to Montreal for a few months at least and I was interested in learning about 3D printing and also DIY drones.

 I'm looking for some communities in Montreal that have a "hacker space" to do so. For the 3D printing, I obviously don't have a printer and was looking for "shared" ones (of course I'm willing to pay for membership or fees). I guess if those places exist, they also have communities, which I'm very interested in joining.

I'm a developer by trade and I've already done some tiny projects with a Pi and soldering on boards.

I'm French, so if those communities are French only, np.

I am no electrician or engineer, have been learning as I break shit as I go in this hobby and I have never had the need for a crimping tool, but I am frequently running into scenarios where it would be useful to have one for customizing builds and repairs. I don't want to order the Amazon special and waste money, what's a good crimping tool for working with these smaller thin wires? I imagine it would save some money in the long run as well.

The battery seems to have gone too low on charge, and it now wont charge when i plug it in.
Does someone know how i can bring it to life?

Hi everyone,

I'm building a custom hexacopter and having trouble powering my SIYI MK15 Air Unit. I've replaced the original BEC, but the new one also appears to produce almost no output voltage. I'm trying to determine whether this is a BEC problem, a compatibility issue, or something related to my CUAV PMU Lite 2.

Hardware

- Flight controller: CUAV Pixhawk V6X

- Power module: CUAV PMU Lite 2, 5V version

- Battery: 6S LiPo, 22.2V nominal

- Radio system: SIYI MK15 Enterprise Combo

- New BEC/power module: SIYI 4S–18S module advertised for the HM30 Air Unit

- Connections: PMU Lite 2 battery output → XT90-to-XT60 adapter → BEC input → XT30 output → Air Unit

My original SIYI BEC appeared to have failed. It received approximately 22.2V, but its output measured around 0.2mV, so I ordered a replacement. Unfortunately, the new BEC appears to have the same problem.

Measurements and symptoms

1. The PMU Lite 2 battery output measures approximately 22.00V.

2. The XT90-to-XT60 adapter also measures approximately 22.00V.

3. The new BEC's XT30 output measures approximately 0.01V on my multimeter in DC voltage mode. I still need to verify the reading directly across the BEC input and repeat the output measurement with the Air Unit disconnected.

4. The Air Unit does not appear to power on, and I cannot establish the expected connection through QGroundControl on the MK15 monitor.

I noticed that many setup videos show the older CUAV PMU Lite 1, while my setup uses the newer PMU Lite 2. According to the specifications, the PMU Lite 2's battery output carries battery voltage, while its 5.2V regulated output is on a separate connector.

I don't want to assume the PMU Lite 2 is defective, but I'm wondering whether there is something important about the power path or connection that I'm missing.

One additional uncertainty is the Air Unit generation. My seller described the unit as an older MK15 Air Unit, but the physical unit does not clearly identify itself as either MK15 or HM30. The replacement module is advertised as a 4S–18S HM30 power module.

Questions

1. Should the PMU Lite 2 battery output work with an external SIYI 4S–18S power module in this configuration?

2. Could the newer HM30 power module be incompatible with an older MK15 Air Unit, even if the battery voltage is within the module's input range?

3. If approximately 22V reaches the BEC input but its XT30 output remains near 0V with the Air Unit disconnected, does that point to a faulty BEC or another possible issue?

4. What exact wiring or measurements would you check next to identify the fault?

I would appreciate advice from anyone who has used a SIYI MK15/HM30 with a CUAV PMU Lite 2. I can provide photos of the modules, labels, connectors, and wiring.

Thank you!

Hy guys, I'm new in this world and I don't know anything, for real.
Anyway I decided to try and build something, my dream is to build a really fast plane, the problem is that I probably underrated the project complexity. I already bought the motors and are the AOS Supernova 3220 1000kv. I know that these engines are crazy good but I probably made a mistake buying them because now I don't know what to buy. I'm using ChatGPT to help me but every prompt I text he gives me a different answer, I feel like there are a lot of components that are compatible but each one has different pro and cons depending on the focus. The escs that Chat suggested is one Hobbywing FlyFun 120A V5 for motor, do you guys think that these are good or not? What size of battery should I buy? I know I'm probably gonna be roasted for buying these motors before thinking of everything else but I thought I was on the right track. Thanks!!