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HELP : 57seconds of strange Motor behaviour

#1
I figured it would be easier to demonstrate the issue I am having with a recent build. The motors are behaving erratically though now I come to type this I wonder if I should swap around the connectors at the board to see if its the ESC/Motors or the FlightController. Im going to go away and try that but since I spent 5 minutes making a 57 second video to describe my pain any thoughts or help are appreciated. As always thanks for reading and taking the time to reply


https://youtu.be/3oSSrcP6LbU
 
#2
Okay I cycled the motor connected on the flight controller and retried the experiment. Im still getting erratic behaviour which looks an aweful lot like a slow increase to throttle despite doing nothing to the transmitter.
 

cranialrectosis

Faster than a speeding faceplant!
Mentor
#3
This looks to be normal behavior for a Naze on the bench.

Think about it. When you have USB support the copter isn't trying to fly the copter. Without USB support the Naze is trying to fly the copter. You put the throttle at 50% and the vibration starts spinning the copter to the right, so the copter reduces torque to two motors and increases torque to the other two motors in order to hold orientation. But there aren't any props on the copter. Reducing and increasing torque isn't making things better so the copter keeps increasing torque to two motors and decreasing torque to the other two until you have two motors at WOT and two stopped.

With the props off, do this again, but this time, hold the copter in your hand and tilt it. If you tip forward the front motors should spin up and rear motor should spin down. You get the idea. If this is happening, go put props on this baby and fly.

Film the maiden. If there is a problem, that video will be a much better example.

Welcome to FliteTest! :)
 
#4
Cheers for that ; I have to say its not the usual experience and this is my fourth from scratch; I'll throw some props and put it out for a maiden but I might tether then frame because if that throttle chops to full it might never come back! Ive put it in my hand and tilted it and seen some respond of the motors but nothing explains the attempts to throttle to full despite nothing on the inputs. I will though give a pop on the props; later though since its 8.30pm here now and its time to catch up on a saturday evening with the famly. Thank you for answering though.
 

Habakkukk

Fly Eagles, Fly!
#5
So cranial is probably correct, it doesn't sound like an issue unless it's behaving this way while you move it around by hand BUT some advice before you go and throw some props on it... do you have it set up to arm and disarm via switch? If not I highly recommend it.
Good luck!
 
#6
Thats a good point about the switch; I should probably have added to the demonstration that a loss of Tx leads to it throttling up hard until the Tx is reinstated at which point it cuts out. Those two motors that stop just slow down but the other two throttle up ; all very surreal but I'll try a couple more things.
 

cranialrectosis

Faster than a speeding faceplant!
Mentor
#7
Thats a good point about the switch; I should probably have added to the demonstration that a loss of Tx leads to it throttling up hard until the Tx is reinstated at which point it cuts out. Those two motors that stop just slow down but the other two throttle up ; all very surreal but I'll try a couple more things.
That's failsafe. Since I don't fly over people, pets or property, I set mine to fall out of the sky upon loss of signal and test it on the bench with the props off every time I connect to CleanFlite.

I also arm and disarm via switch. No matter what, I can return that copter to the ground whenever I choose. :)
 
#8
I fixed the issue; here is what I did.

I stripped it back down to check I had not introduced any shorts or bad wiring; I then dumped a config from one of my Hurrican MkII Quads and pasted it into the the Naze and rebooted. I then ran up the motors and the error still occured; so I took a closer look at the spin direction of the motors and I could see that 1 & 4 were spinning in the wrong direction; A quick swap and test fixed the issue and with the props on the board I had a working quad; I removed the props; reintroduced the error in wiring on the motors and retested ad recreated the error. So it wasnt ground proximity or vibrations offsetting the motors as when wired correctly they spun up and down and did not randomly stop and start. Im going to chalk this one up to tenacity; that quad was a learning frame for me to play with kit on and off quickly so what I have learnt is; strip back, review, look twice and test thrice.

The next stop is to start learning more about the FRSky Taranisplus configuration ...