As you say nothing in the log to see.
Are you using the Vx BEC for anything? That’s good for 8A
Checked volt calibration again yesterday and its fine. Landed yesterday at 12v which it 3v cell, fine for Li-ion.
Anyway the crashes have all happened a short time into the flight with fresh batteries.
Have you measured the pack voltage after a crash event? Not just the HUD readout - a multimeter reading of the pack?
This all reeks of a power issue, and the logs aren’t telling the story, so looking for other sources of data for confirmation.
I didnt put anything on the Vx. I should have. Was really convinced I had a bad H743.
The crashes have always been on short flights. None of them have occurred on any endurance tests. Today was only after about 3 minutes with a fresh 18Ah batt.
I know, thats why Ive really been looking into that but I now dont think its that.
It did sound that way. If you wanted to investigate if the 5v BEC you are using is dropping, connect it to VB2 and configure a 2nd Battery Monitor. Just know that’s a 20:1 divider.
Or, connect all to the 8A capable BEC😀
Agree that it seemed that way till it happened again.
I think you said something about the servo rail. How are you powering that? What devices are on it?
Nothing is on the servo rail. I did intend to power at least the RX from it but didnt. We did discuss it and the claimed capacity of the 4V5 should have been more than enough for RX and GPS but who knows.
From the logs, the MCU Mvmin looks ok and has been much lower on the endurance flights, which didnt crash. I cant see any other volts in the logs, apart from main battery.
I do suspect one of the peripherals is dragging down the rail but how many more crashes before I figure it out?
Did you see my new post about how to exercise the copter as if its in flight? I will put some printed plastic bars on the motors to give some vibration and hopefully leave it to ‘fly’ and see if I can recreate the problem.
I did see the post, but I don’t have any good suggestions about that. I think you’ll mostly saturate the control algorithms really fast and trigger crash or thrust loss messages.
Has anyone looked into maybe the autopilot shutting down due to thermal issues? Power would be my first guess too - but thermal could act similarly with an abrupt stoppage in logs.
It was showing 64 yesterday during a long endurance flight which worked perfectly. This morning it was 41 when it shut down.
The IMU and Baro Temps are normal. No other temps to look at.
Ive just done a short test, hoping to see a very short drop in MCU volt when the battery is disconnected but it shows none. Just stops dead like the logs crash logs do.
Does it reboot or stay dead?
Every crash the battery has stayed connected and the FC appears to be flashing normally. Yaapu telemetry stops for a short time then restarts from the pile of bits.
Another same crash. This is a very crewel problem.
Have spent a month designing and printing a new low vibration frame for my 14" equipment. It has exactly the same symptoms as the previous crashes, ie just drops like a brick and nothing to show in the data (or telemetry) logs.
Since the early crashes it has a new FC (matek H743), new battery, new frame, different 433 telem radio, new GPS, 4 different motors and all new cables and connectors. All peripherals (except the new CAN gps) are now powered of the servo rail.
Whats the same as previous crashes? 4-in-1 ESC (Tmotor 55 pro) and a TDMX frsky RX.
The ESC may seem an obvious culprit but it was working fine in a much bigger copter. The FC is not powered from the ESC. The FC is connected directly to the battery.
It was the second flight of the day, the first one being the first flight of this new setup.
What about the RX? Unlikely it could freeze the FC, especially now its connected on the high current servo rail.
So I have a smashed new M10 CAN GPS £90
Smashed frame.
Smashed telemetry radio.
Very hard to get motivated to rebuild and buy new bits.
Here are the logs. The latest crash is called ‘vibe frame’ . Any ideas welcome. Also check out if I succeeded in making a low vibe frame.
Its very unfortunate when these things happen and even harder to diagnose the issue.
I haven’t looked at the logs but is the FC recording the crash or is the logging stopped at the time of the crash ( power to fc is lost)?
Or is the FC in some kind of fail-safe?
I have a similar issue with INAV and my copter will loose all RC Inputs and then recover, but I cannot solve the issue.
Logs just stop in the air. Up to that point, nothing unusual. After every crash the battery has stayed connected and the FC lights are blinking as normal.