Ok thank you Tomas for reply, I really do appreciate it as I know you're very busy and time is limited.

I am thinking something from possibly esc or motor caused electrical discharge as one of the esc motor leads had a small cut in it exposing wire, although i had electrical tape around it I am wondering if this somehow caused a problem.

There has been an interesting update on the problem I had while discussing failsafe with a user on helifreak. By sheer coincidence the user had replicated what seems like the exact failure I had. I quote his message.

[QUOTE=dogbreath;7943569]I have a Rex7 ExBus into Spirit 2 on a Synergy 696. Scorp ESC leads are plugged into aux 1 and Aux 2 with the signal pin from aux 2 into PIT for RPM. Scorp telemetry set for exbus and goes directly into the Rex 7 (so E1 and E2 are both used). Here's what the manual says about REX failsafe:

6.3 Main Setting
Fail Safe - switches the Fail Safe function on and off. If the Fail Safe
function is disabled, there are no signals generated on receiver
outputs in case of signal loss. If the Fail Safe function is activated,
the receiver outputs are generated according to your individual
channel setup selections in case of signal loss („out off“, „hold“,“ fail
safe“).
Signal Fault Delay - the time interval from when the receiver
detects signal loss to when the fail safe control throws are initiated.
After the expiration of this time, the receiver outputs will transfer to
your selected individual channel outputs.

This tells me there's no "failsafe" signal. You either get a channel signal (hold, channel failsafe set) or no channel signal (channel off). The delay may work like this:
1. Xmtr signal lost, channels off
2. Failsafe Delay kicks in, failsafe channel output starts.
3. Xmtr signal returns, all channels revert.

This would jive with what I saw earlier that even with the 1.5 second delay in rx failsafe, the motor spun down immediately (no signal sent-Spirit failsafe kicked in). Next test step would be to un-set Spirit failsafe and put a non-zero throttle in the rx failsafe and see what happens. I don't have time now, so that will be for later in the week.

One thing that did concern me was with the motor spinning and the transmitter still on, I unplugged the exbus pin from Ele/Pit/Ail and the motor continued to spin. I plugged it back in, hit throttle hold, and nothing happened. Motor didn't spool down until I unplugged the battery. That needs more looking at as well, and could potentially be bad if the rx signal came unplugged. Can anyone do that test and see what they get?

Dan[/QUOTE]
I have highlighted the most important part of the message. This is exactly what happened with my unfortunate experience. I'm replying here to make people aware of this as a potential and dangerous issue, also for your information as well Tomas as maybe you can also look further into this.

Thank you for your message.

Unfortunately we can't see anything wrong. Also nothing changed in EX Bus for years.

Simply when you plug the EX Bus cable off Failsafe from unit must always trigger.
If this is not the case then it mean the unit is not operating anymore.

We can plug in and plug off the cable how many times we want and it is working always in the same way.

There is potential risk you are transfering static discharges through your fingers to the unit, especially if you are on a wheelchair and/or a carpet or you have clothes that are producing discharges.

Please let me know a instructions to replicate the problem if there is something else we should know.

_________________
Spirit System developer

Thank you for the reply Tomas, I will be testing this hopefully more over the weekend. The problem to me seems to be there is no fail safe function if the exbus cable becomes loose or dislodged temporarily as the spirit unit does not respond to any RX input after this event. This has now happened twice to 2 different people on 2 different setups in 2 completely different parts of the world. In my circumstance there was no human interaction with the heli, RX, or spirit unit so human static discharge is completely impossible. As I said I will test this again myself as now I am aware of what potentially caused my problem. If in fact it can be replicated more times then this is an extremely dangerous situation as there does not seem to be any activation of failsafe from spirit unit.

Please share your settings. With our settings the problem can't be replicated in any way. The failsafe is always triggered.

_________________
Spirit System developer

Dear,

This looks familiar to me too
I have a SAB Comet racer, with SAB motor and esc.
Frsky transmitter and receiver, uspirit fbl unit.
Servos are the SAB servos(eeeh, were).
I’m currently waiting for other servos, just to be sure.

In flight, I encountered a beautiful sideward turn, causing a crash.

After rebuilding it, in several test runs with motorsignal wire (AND BEC) running from uspirit to esc
Sbus from receiver

During testruns (no blades) on my table, I encountered sudden loss of control but with continuing running of motor.

Eventually it seemed ok. Motor on receiver again, looked good. But it crashed again, luckily low rpm low altitude (with a new uspirit).

BEC test was good. But...

The suggestion of low BEC current sounds logical, while these events only occurred after a while. And indeed... no record of it in telemetry

So... when I have it flight ready again, I will try it again but without BEC... have to find a small battery.

blarks: If motor is running and there is a belt then static discharge is very probable actually.

Unfortunately there could be same outcome for a very different scenario, so it does not mean that this really happened.
The only thing we can be sure about is that the unit was not operating (correctly) anymore for yet unknown reason.

You can see what will happen with or without motor running.

_________________
Spirit System developer

In my case... only with motor running and after a while
Indeed with a belt, but that still doe not rule out low BEC

So... preventive measures are necessary for static discharge

Interesting idea

Could you describe what a static discharge does with the unit?
Does it result in damage to the spirit unit or only ‘stunning’?

Preventive measures would be making a electric connection between tail rotor unit and metal main frame I guess?

Are there ways to measure a static discharge easily?

No most definitely a static discharge can occur with belt heli's. It doesn't explain though why in both in my case the failsafe and throttle hold didn't work and in the other instance exactly the same things happened where throttle hold didn't work nor did failsafe initiate when transmitter was turned off. Here is a link to helifreak Tomas,
https://www.helifreak.com/7944277-post84.html
you can see that Dan in that thread was not able to again replicate the problem he had before, the same as that I was not able to replicate my original failure again either. Its seems a very odd and let us hope a very rare occurrence. I am thinking it may be a combination of a static discharge and a loose wire or connection at the same time causing a confusion in spirit. This is maybe why it is difficult to replicate the problem. You can see what I wrote in reply there and I think with proper care and precaution with wiring and connectors hopefully any future failures can be avoided. But I think it is good that you as well as everyone else can be aware of this issue even if it is only a very rare case.

I would like to thank for your continuing support, I along with others very much appreciate it. The spirit is the only unit I fly with at the moment and enjoy using them.

One thing that made me think and I am unsure if this is even possible or a very good suggestion, but is it possible to create some sort of failsafe trigger occur after a certain amount of time where no stick input is received by the spirit unit? for example if no transmitter stick input is received by the unit say after 10 seconds then the unit can go into a failsafe condition.

Tomas what is the preferred method for setting failsafe, in the spirit unit, in the RX or both?