Hello,

Hope all are well. I have a trex 500 with a spirit fbl and have random, unpredictable times when the swash starts leaning during spool up and the heli almost tips over. I lost one set of blades but have my finger on the hold switch now and usually can avoid another tip over. Why would this happen?

I assume if there were vibrations, this would occur more often. Is there anyway to troubleshoot this? I have the latest firmware. Servos are hitech if that matters.

Thanks

Hello

Possible problems are:
- extremely high vibrations
- some mixing in your transmitter - CCPM enabled in your TX?
- do you move with the sticks during spoolup? (swashplate should be in the horizontal position)

You can measure vibrations easily, so I recommend to do so.
If this is the reason, then something is very, very bad.
It can happen also occasionally depending on e.g. temperature of bearings.

_________________
Spirit System developer

Are you trying to lift off with sufficient head speed?

Thanks for quick reply as usual.

If vibration related, why would it occur intermittently? Same for CCPM mixing-- there are times when it flies really well.

I do not touch sticks until I am off the ground.

If I see the swash tilting during spool up, should I attempt to correct ( I think I know the answer-- no input while on ground or fbl reacts).

Plenty of headspeed 2500+ . Thanks

Some vibrations are occuring only sometimes - for example resonant vibrations can occur just in a specific conditions.
It could be also issue with some loose connection so I recommend to verify all cables.

You can correct it by sticks so that swashplate is in the horizontal position again. But if input is too high it could tip to opposite side.

All in all, this should not happen in any case. So the reason why it happen is likely very dangerous.

I recommend to disassemble main blades and to spool up motor on the ground while watching what is happening.
Then you can measure vibrations to be sure that it is OK (especially Y axis).

_________________
Spirit System developer

Thank you. I will do that.

The log file does not record high or extreme vibration occurrences, is that correct? So the vibration analysis has to be live to find these vibrations.

You are welcome.

If there is no major error then high vibration event in the log is not saved permanently. Otherwise it is saved.
But still I recommend to start Vibration Analysis which will tell you a lot more. It is good to check the heli even if everything is OK.

_________________
Spirit System developer