Good to know, I'd have probably never figured it out. Like i said, i've ordered a few Sunon fans to replace the standard HW supplied ones, in the meantime I'll just leave the fans disconnected.

Well we can rule out the HW fan as the cause. I disconnected the fan and it was doing the exact same thing. I shot a video to illustrate the problem.. Any help much appreciated because I'm struggling with this one:

damn

Something i missed previously, i noticed in the video that the elevator servo didnt jump on initialisation indicating an error in the log, so i checked. There is only one error which reads:

'Main Loop Hang occurred'

Only problem is that this log was recorded while on the bench and connected to PC by USB, so it might not be representative of the 'real' error which is causing the problem. I'll have to recover a log at the field following one of these swash misbehaving episodes.

We have found that the fan is causing troubles even when it is quite far.
So possibly it is electrical and mechanical problem. With other fans we have not found the issue.

_________________
Spirit System developer

It does this even with the fan disconnected (like in the video).. so it's not the fan

Ah, I have checked the video and it is definitively not correct.
But it is rather not a direct cause for a tip-over.

The tip-over could occur only if the swashplate will be tilted during spoolup. That mean you have to move the swashplate with stick to a tilted position in which it will probably stay which is not good of course. But at least it can be prevented.

I would like to ask which firmware you have installed in the model, what BEC voltage is used and if you have something connected at the SAT ports?
This is because the problem is occuring mainly because of temperature difference. Normally this should not happen but the reason for this problem is that the sensor is drifting. And drifting is caused by increased temperature. And temperature could rise when something wrong is connected at the SAT port which is drawing too much current (e.g. faulty satellite) which is even more apparent with higher BEC voltage.

So I would like to ask if you can disconnect everything from the SAT ports first to verify if it will help.

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Spirit System developer

Thanks for the suggestion. Temperature drift actually makes complete sense because I've only noticed the problem in cold conditions, I can never repeat the problem when i'm indoors at room temperature. Now you mention it, i did also notice that the Spirit felt slightly warm to touch but I assumed that was normal.

In the SAT ports I have data input from my Hobbywing ESC (using the correct 'UNI' cable and which works as it should transmitting data back to the Tx) and in the second SAT port I have a Spektrum DSMX satellite, which is working normally (it displays a solid LED indicating a good bind).

I will try removing Sat port connections plus I will carefully check the wiring for shorts etc and see if that prevents the problem. Unfortunately it's not easy to test because of the intermittent nature of the fault.

Firmware is the very latest version 2.5.2. I did not notice this problem on previous versions (but i'm not implying it's a firmware problem). BEC voltage is set to 8.0V


PS... you are right in that the swash only tilts due to stick input, so now i know what to watch for it should not cause an accident.

Just been doing more testing. Because the problem is intermittent it makes it very hard to diagnose positively.

With the heli outdoors (quite cold conditions) and both the satellite and the ESC data cable connected the fault appears two time from two attempts.
I removed both satellite and ESC dats cables and fault went away on the next two tries.
Connected ESC telemetry and fault was still not apparent
Connected the satellite and the fault came back

.. so looking like a satellite problem at this point...

I changed the satellite for one I had spare (that i know works) and re-bound the satellite. It was ok on first try but then fault came back. I
changed and re bound with a third satellite and again the problem came back about half the time. I tried a different cable, same thing, problem showed up intermittently.

So based on the testing, it's looking possible that there is an issue related to the Spirit itself that shows up only when a satellite is connected, but the fault is intermittent and appears possibly to be partly temperature related.

I need to do more testing to prove positively that the fault only ever happens when i have a satellite connected but so far after about 15 attempts it's always been good when no satellite was connected. What is more confusing is that sometimes with the satellite connected it's ok and sometimes it's not, which is very confusing.

So more testing today. So far the fault has never showed up when i have the satellite disconnected, but it shows up intermittently when the sat is fitted. ive tried three sats and two cables, no improvement. i also tried setting BEC voltage to 7.4V but the intermittent fault remained.

At this point it does seem to be looking like a fault with the Spirit. i have 5 other Spirits including another three with identical hardware setup and they dont do this.