Brain 2 motor cuts ...
 
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[Solved] Brain 2 motor cuts out


l.gomes
(@l-gomes)
Active Member Customer
Joined: 3 months ago
Posts: 11
Topic starter  

I just upgraded my Trex450 to a flybarless setup. The motor cuts out for a split second several times at about 75% throttle. I have a 40amp ESC. I'm not sure what motor I have. I have a few, Align and generic. Futaba T6EX with all connections from reciever to Brain2 correct. It looks like my power isn't consistant. Does it look like I need a more powerful ESC?


BrainDev
(@customercare)
Member Admin
Joined: 4 years ago
Posts: 780
 

Please can you send here a flight log of your unit where the throttle cut out happen?

Thanks


l.gomes
(@l-gomes)
Active Member Customer
Joined: 3 months ago
Posts: 11
Topic starter  

I didn't have logging enabled at the time. I'll enable, replicate the problem and send the file.


BrainDev
(@customercare)
Member Admin
Joined: 4 years ago
Posts: 780
 

Hi Nick,
Thanks
At this point also check that the values recorded in the Recorded Logs are the default ones.
In recent versions of the software we have added in the File menu the command "Reset Logs to defaults ..." that resets the 12 values recorded in the logs to the default values.
Only from the logs it is possibile verify if there are power problems, if there are problems in the frame rate of the radio signal, if there are problems in the reception of the throttle in signal received from the receiver (Rx Fail Safe), if when the RPM drops the throttle out signal goes to zero or not (ESC protections, One way bearing slipping, etc.), etc. etc. etc.

The flight logs are used to try to diagnose what are the real causes of the problems and where and what to look for. It is therefore always a good idea to keep them always active.


BrainDev
(@customercare)
Member Admin
Joined: 4 years ago
Posts: 780
 

While waiting to receive a flight log so we can graphically check how stable and clear the supply voltage is, we analyzed the configuration file sent to us and saw that you use a standard receiver.
With standard receivers and separate PWM channels for each radio channel, the Throttle receiver signal is connected directly to the ESC. Therefore, the Brain flight controllers are not involved in any way in Throttle control and if any motor cut outs occur it can only be due to the receiver and/or ESC and/or motor and/or motor battery and or one-way bearing slippage. Even the Fail Safe function of the Brain flight control units that for safety bring the Throttle to zero in case of signal loss is not involved because the Throttle is not physically connected to the flight control units.

Checking the Events file, we see numerous "Voltage <= 4V3" events that indicate a drop in supply voltage at which there are also "Receiver Signal Off" events.
So your problem is a servos, flight controller, and receiver power supply problem, that which with insufficient power supply, loses the radio signal and brings the throttle output signal to zero.


BrainDev
(@customercare)
Member Admin
Joined: 4 years ago
Posts: 780
 

To solve the problem of the ESC BEC voltage, the better solution i to use an ESC that has a higher BEC output current (Remember that in an upgraded flybarless models servos do more work than in flybar-assisted models and draw more current)..
However, you can also try to reduce the current demand from the servos, which are the components that have the highest current draw compared to all others (receiver, flight controller).
- Make sure that no servo is ever in any condition (at the corners of the sticks) go to binding (otherwise reduce the output range).
- After releasing all swashplate and tail links check that the swashplate runs freely on the main shaft (otherwise lubricate), rotates freely on its center bearing (otherwise lubricate), that the tail pitch control runs freely on the tail shaft (otherwise lubricate).
- Use a lipo battery pack that is in good condition, fully charged and balanced and has a sufficiently high C-value (otherwise change the lipo pack).
- Use connectors between battery pack and ESC that are of good quality and have a high current rating (otherwise change connectors).
- If the battery and ESC cables are too long, shorten them (the cables also have their own current drop).
- Add a 4700uF electrolytic capacitor to act as an energy reservoir during short current peaks by connecting it to a free connector on the flight controller (e.g. CH2) or the receiver.


l.gomes
(@l-gomes)
Active Member Customer
Joined: 3 months ago
Posts: 11
Topic starter  

Thanks for all the information. I enabled logging, removed the rotor blades so I wouldn't crash. I can't duplicate the problem with the rotor blades removed. Seems to be taking down apms with stress. I'm getting an 80amp ESC and will try tomorrow.


l.gomes
(@l-gomes)
Active Member Customer
Joined: 3 months ago
Posts: 11
Topic starter  

80amp esc solved my issue. Thank you for leading me down the right path.


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