Brownout? help with loss of power

[skifreestyle]

Hoping some folks can tell me how to troubleshoot this issue. I've never had a brownout but i don't know if this is one. Here's the issue:
I was 45 seconds into a flight. I was doing some tight flips and while inverted the power just cut out. Hit the TH. Luckily i was over soft grass and only broke the skids. I double checked the pulse battery and it was 4.13 - so lots of juice. the motor was pretty hot. outside temp was 80 degrees. i was running 85% flat curve. i've flown many times without any issues. after the crash, the servos and esc were working fine.

i figure its the ESC or motor... what would you do to track down this issue?

Heli setup:
300x - lynx main blades
don's wicked motor
lynx main gear 12 tooth pinion
hitec servos
talon 35 w bec
zyx-s

Thanks for the inputs

[vronny]

Originally Posted by skifreestyle

Hoping some folks can tell me how to troubleshoot this issue. I've never had a brownout but i don't know if this is one. Here's the issue:
I was 45 seconds into a flight. I was doing some tight flips and while inverted the power just cut out. Hit the TH. Luckily i was over soft grass and only broke the skids. I double checked the pulse battery and it was 4.13 - so lots of juice. the motor was pretty hot. outside temp was 80 degrees. i was running 85% flat curve. i've flown many times without any issues. after the crash, the servos and esc were working fine.

i figure its the ESC or motor... what would you do to track down this issue?

Heli setup:
300x - lynx main blades
don's wicked motor
lynx main gear 12 tooth pinion
hitec servos
talon 35 w bec
zyx-s

Thanks for the inputs

Did u check your connections from ESC to motor or maybe a bad solder spot.

[D22597]

Have you ruled out ESD (static discharge) ? Did you silicone the belt and/or ground the boom?

[skifreestyle]

Good call on the soldering. I'll take a look. As far as the belt goes I do silicone it from time to time. How do you stop ESD? Boom is carbon.

[DoubleCH]

Originally Posted by skifreestyle

don's wicked motor
lynx main gear 12 tooth pinion

May or may not be the cause but that's way too tall gearing. Don's should be 4800kV. With 12T that's supposed to be good for 4100rpm governed but of course the motor does NOT make anywhere near enough power for that. That 330W motor needs at most 10T to run optimally.

[D22597]

Originally Posted by skifreestyle

Good call on the soldering. I'll take a look. As far as the belt goes I do silicone it from time to time. How do you stop ESD? Boom is carbon.

Run a small gauge wire from the boom to a motor mount screw. I assume cf boom acts the same since it's conductive. This is an example for the 500x, but same process.

https://www.helifreak.com/showthread.php?t=633142

[Tim Wolff]

Do a range check too. My 300x started shutting down after I tie wrapped the silver part of one of the antenna to the boom support. Apparently this effectively masked that antenna and created a dead spot. Failsafe triggered and shut off the motor. Replaced the ESC, reflowed the solder on the motor plugs, ETC. Cut that tie wrap and it has been fine since.

[skifreestyle]

thanks a bunch for the suggestions guys! I was able to find the problem: vronny's hint was the ticket. I found a small section/nick of the + wire from the ESC connector was worn through to bare wire. i wouldn't think the silcon wire insulation would wear through but it did. the bare spot must of come in contact with a motor connector or something and it momentarily shorted. it's all fixed up now.

Taking doublech's advice i swapped out the pinon as well, i didn't have a 10 but had a 9 so i'll see how that works out later this week & start with the range check for good measure.

[cfossa]

Hi,

I'm having a similar problem. I too found a bare spot on the ESC wire and covered it with heat shrink. But, the momentary loss of power is back after a few flights.

Is your problem still resolved?

[skifreestyle]

After heat shrinking the bare spot my issue is gone. Check the leads off the motor for any cuts or places the May have rubbed bare. Also make sure the capacitor on the esc doesn't have a broken wire. It's a relatively common problem.