Hello ? Why did the APM shut off Motor #1 ? Does anyone care there could be a serious problem here ?

Large Hex with APM 2.5..  3.0.1...

Lots of time flying... No problems... Very stable... Loiter Perfect after tuning...

Take off, kind of fast... Motor #1 stops in the air... copter spirals down... does not power up

when I apply more power...

I figured motor / ecu fried... whatever...

I download the tlog..   The APM shut down the motor in mid flight... whats up with that..

Am I reading the tlog correctly ?

Eddie Weeks


Views: 866


Reply to This

Replies to This Discussion

From my understanding, APM only logs *resulting* motor RPM, not the "in" rpm. APM does monitor throttlein vs throttleout (but it does not do this for individual motors), so you can compare what throttle was delivered vs what was asked. Same also for 3 axis of rotation. I stand to be corrected on this one.

APM also has a minimum motor throttle setting, which should prevent complete motor shutdown.

If you had an immediate and complete shutdown, you might have a fried ESC or motor or a popped motor-esc connector. Does your motor still spin freely? This is the more common scenario. That's what happened to me; upgraded to 4S from 3S, and one of the ESC's fried (even though it was rated for 4S). It looked like the APM had just shut the motor down, but actually it was the ESC frying itself.

The tlog above clearly shows pwout1 going to 1200 at 50 feet... 

That means the APM turned off the motor...  !!  

Well....  the problem is not solved...   If my radio went hard over, as the red line shows, why did the copter

fall like a stone and not power up at I gave it more power ?...  light Blue line ????.. 

And also... A motor should never stop in the AIR...  The APM shut the #1 motor down.... that is clear

Does anyone have an explanation for this ??   Its been over a week..

I fixed the copter and loitered it for >30 min... Same motor, same ECU,... same everything..

Hi Eddie,

The logs you post are from two different flights so that makes it difficult to analyze. The TLOG shows the problem.

BUT its not a motor shutdown, if you look at your RC input at exactly the same time as Motor 1 reduces power and motor 2 increases you will find several command inputs going on. Not least of which is a commanded throttle drop and roll.

Therefore you either have a problem with badly calibrated speed controllers or a bad bearing in motor 1 that stopped it on commanded low power.


Ok thanks.... now that someone who know how to look at these logs has determined

the output followed the input..

Its looking more and more like my  Radio messed up..   Its a hitec aurora 9 ..... 2.4

I never thought a 2.4ghz system could screw up like that but I guess it can... I was only

50 feet from the copter when all this happen..

The copters is flying again fine with all the same parts...(new sticks and props)  

This copter  will be used for stack inspections so it needs to be as reliable  as possible.. !!

Thanks for your help

Reply to Discussion



Season Two of the Trust Time Trial (T3) Contest 
A list of all T3 contests is here. The current round, the Vertical Horizontal one, is here

© 2019   Created by Chris Anderson.   Powered by

Badges  |  Report an Issue  |  Terms of Service