Motor is hanging

[Kalle]

Em the sad thing is think u understood me right just my english is bad^^
ok again:
I changed the motors by turning the top motor(Motor A) on the bot and bot (Motor B) on the top
i switched the cables of both motors are going through the pipe to the ESCs there i switched the cable from motorA to the ESC of motor B and the cable of motor B to the ESC of motor A
Motor B is showing now the problem motor A had befor and Motor A now on the bot is working fine.
i didnt switch the position of ESC A and ESCB they are still on the position befor

[chschmid]

Kalle
Your problem occurs always at the same position with different mot/ESC. Check the shielding.
An easy way to test is wiring the signals outside of the arm/boom and hook it up to a testing device like Unitest or to your Rx. If that works its most probably your shielding.
Maybe you could make a drawing so can better understand what you already tested.

Best
Christof

[bluuu]

and one more, maybe replace existing signal wiring (for test)

[LordPikaChu]

Can you post a log file from the flight when this happens?

I think that this could be a motor/ESC sync issue that you can only see happening on one motor. I've had a similar situation before when my ESCs had sync issues with T-motor MN3510 motors. When bench-tested, the motors were spinning as they should, but as soon as they were hooked up to AutoQuad - the FC started quickly changing PWM values to stabilize the copter and sync problems appeared. What's interesting (and similar to your situation), at first I could only observe sync issues on two arms (number 2 and 5 in hexa). I then tied down the copter and run the motors for longer periods of time and occasionally other motors would loose sync, but this was rare.

What this all means is that due to some kind of imbalance (motor mounting imbalance?) only two motors would usually loose sync because the PWM signal sent to them was different than that sent to other motors. By different I mean higher RPM requested form these two motors or switching speed from low to high faster. You will see this in your AutoQuad logs - overlay all motors in your log viewer and see if the motor loosing sync has noticeably higher or different looking throttle values that other ones.

Although you seem to be using high quality ESCs, they look like they haven't been designed to handle multirotor pancake motors, and this is why you may experience sync issues. Some T-motor motors are very picky when it comes to ESCs.

[Kalle]

Thank u very much for ur post!
Right now its raining so i cant really fligh i will try it tomorrow when the weather is better. But if i understood u right its a problem i can fix by chaning something on the fc? The ESC are working very well with the motors when iam trying them without the fc. The ESC are not made for multicopter thats true they are normaly used for helicopters if iam not wrong. But i heard that the quality of them is very good and the equipment already was not so cheap so i thought its wrong saving money by the esc.

[bluuu]

ok, after test post your log from AQ

[chschmid]

[LordPikaChu]

[Kalle]

So i needed much longer than i thought weather and studys are taking the time :-/
i finished now all of the things your guys told me (i hope i made it right).

Test 1 Normal + Record
A=2
B=7
C=8
D=10

the motor D is not working (hanging after a time) when iam flying i was recording everything i hope you can read something out of it i tryed but i dont really understand what should be wrong with the signal.
Link for the log file: http://www.file-upload.net/download-981 ... L.LOG.html


Test 2 D motor switching with the motor under him (iam using a X octoframe with all motors on it but for the tests iam just using him as quadro that i can replace the motors easier with the motor under them if something should not work)
The motor D* is not working (hanging after a time)



So like u can see in the picture i tryed both ways and in both cases the motor on the top is not working the motor on the ground is not connected with the fc

Test 3 changing the port
D was on 10 i switch it to 14 ==> still not working (hanging after a time)

Test 4 changing the port
D was on 14 i switched it on 12 ==> still not working (hanging after a time)

Test 5 Checking if the ESC are programmed in a other way than the others
I checked all of them all of them are the same way programmed

Timing: 30°
Brake: off
cut off type accutype: slow down / LiPo
cut off voltage: 2.4 /3.1
Cells: 12
Act. Freewa. Gov. Mode: Freew. on / Gov off
Start up Speed : Heli middle
PMW Frequenz : 10 kHz
Start up Speed: Auto 1-32%

All are programmed the same way

Test 6 EM noise
I made the cable of motor D out of the arm away from the main powercable
nothign changed still the same problem the motor is hanging after some sec flying

The only thing i didnt do until now is calling the company of the ESC to ask if they have a problem with the PWM signal you told me aout.

i hope someone can help me by giving me a new idea...

i hope the problem is not that the motor and the ESC are not in harmony...i cant really understand because the other arms are working and why should be the problem always on the same arm and not on the other arms?

Thank u very much for reading my post
Marco

[LPR]

Marco

I've helped build a couple of U8 quads and have had a problem with them stalling but not often. We found that if the voltage drops too much, because of a high load on the batteries, a motor can stall. If the wires that power your motor that is stalling, are longer or are a thiner gage than the rest of your motors wires, that may be why the one motor is stalling.
If just a little longer or thinner wires are the problem I would use thicker wires for all the power wires for the ESC and use batteries with higher C ratings.
I always test an ESC by using a switch to adjust the U8 RPM from one speed to another for testing to see if I might have a stalling problem. Using the Joystick is too slow to get a motor to stall.

Using the ESC that are recommended by T-Motors might fix the problem. If one motor is stalling most likely they all will at some time.

U8 are known for have stalling problems.

Here are some links.

http://fpvlab.com/forums/archive/index. ... bb035a5c3a

http://fpvlab.com/forums/showthread.php ... EXPERIENCE

http://www.rcgroups.com/forums/showthread.php?t=2179298

The ESC32 V3s should be available soon and they are lighter weight, more efficient and should definitely stop your stalling.

Larry