Q500 4k Motor failure?

[maknak]

Hi There,
One day the thread at motor A was damaged (i used drone maybe 25-30 times), drone was still inside warranty (10th month). Called laptopdirect.co.uk to report warranty, they have send me to Yuneec UK, i send same emal to Yuneec UK where i was informed that my drone is outside warranty (!?!). After 2 weeks of going back and forward Yuneec finally agreed that damage will be covered under warranty. They suggested to me that they can send me motor if i am able to fixit myself. I have agreed (F****) and replaced motor without any problems. After replacement this new motor was pulling whole drone to its side - service knew but they hided this fact that you must replace 4 motors. Now i have rethreaded old motor. However it is still not working. Looks like now old motor does not have enough power and drone is flipping at this side.
I dont know what to do... shall i buy 3 new remaining motors and then it would work. Maybe i have some ESD problem , maybe something needs to be set (i did setting via PC - all fine). .... and i was going to buy Dji.....

 

[jannislh]

The main reason for damaged threads on the Q500 are incorrectly mounted propellers. Since the propellers have different threads they have to be screwed on to the right motor.

There is no need for replacing all motors. I have no idea where you found this information.

A flipping drone might be caused by mounting the propellers in an incorrect order (same reason why the threads get damaged). Please make sure everything is right. Unless one of the motors smells burned it should not have less or more power than the others.

 

[WTFDproject]

Two quick thoughts:
1.) Please ensure you used the Q500 GUI to assign motors. The 350QX GUI motor assignment is done in the reverse order.

2.) Also, ensure you soldered the motor wires in the correct order when you attached the ESC. All four ESCs are wired in the same order.

The attached picture may help:

 

[maknak]

@WTFDproject
1. Yes my GUI went fine i have all for motors tested and calibrated acc. All in green as per Q500 screen attached.
2. I reconnected everything when it comes to cables (plugs and soldering) at ESC board which is at the motor.

@jannislh

How i can mount propellers in different way ?!?, sure they are done in PokeYoke - full proof. , i am mounting them correctly there is no other way.
Yes you can find many tutorials that are advising 4 motor replacement.

Maybe i will record video showing how it is working.
Now it looks like that my old motor is weaker....but i do not understand why. Maybe my soldering mass has different conductivity and resistance is higher.
Do not have a clue.
I am looking at new motors now..

 

[WTFDproject]

Maknak,
I will not try to dissuade your order of 3 new motors. It’s always good to have spares. But jannislh is correct, new motors will not help with your current problem.

You mentioned the “A” motor. The Q500 has two “A” (clockwise) motors, and two “B” (counterclockwise) motors. Motors 1 and 3 are ‘A”, motors 2 and 4 are “B”. Which motor is giving the problem?

Do the new motor, the old motor, and the other three motors all “feel” about the same when rotated by hand?

Do all motors "sound" about the same when run tested on the GUI ?

Is the problem motor rotating in the correct direction? (If any two of the three motor wires are reversed on the ESC, the motor will test fine, and show green on the GUI, but will be rotating in the wrong direction.)

Is there any sign of damage to the “old” motor, or any debris inside? The magnets have a habit of picking up bits of metal, such as the small screws you probably removed to open the shell.

 

[WTFDproject]

Should you need to disassemble the motor to remove debris, these pictures show the parts that must be removed.

Remove the snap ring and all spacers from the lower end of the motor shaft.



This motor had two spacers. It varies.



Pull the top of the motor and shaft out of the base. It may be necessary to tap the bottom of the shaft to get it moving.

 

[maknak]

Hi There,
The problem is with the "A" Motor. I do not use my drone often and since i bought it i have noticed that twisting is a very poor solution and dont know who had this idea to put this in place (this is my occupation background). After about 30 flights the thread was sized. (see photos)
The trouble began when i put new motor replacement.
AT the GUI i tested all motors and i was looking for the sound but all are working same. ( I was looking at the direction just to be sure and all were as per picture in the GUI - then i was observing move with propeller on and all are spinning with same direction as on the picture). However after replacement i can hear strange noise once propellers are mounted - this is not right. Noise is present with the New motor as well as with old - so this is my unknown.
I was thinking that maybe controller is trying to balance this single variance buy 3 remaining motors and therefore props are spinning with different RMP/s.
I will demount this motor one more time and check for debris as you specified above.
In meantime - Thank you for your time guys - really appreciated.

 

[WTFDproject]

[QUOTE="However after replacement i can hear strange noise once propellers are mounted[/QUOTE]

A thought. Is it possible the propeller is damaged?

 

[maknak]

[QUOTE="However after replacement i can hear strange noise once propellers are mounted

A thought. Is it possible the propeller is damaged?[/QUOTE]
Yes it was damaged and i used all 4 new of the spare ones which comes with the Q500 pack (just to eliminate anything in between . Because once thread was sized at the motor it sized the thread at the propeller as well so i couldn't use it again
Today at evening i will dismantle the motor like you said and we will see. ( i was flying on one beach.... maybe something went into ..

).

 

[WTFDproject]

Loved the video. It is always interesting to note how much is the same, and the things that are different, in the places our members live. This beach is a beautiful place, and you captured it well.
I live between the mountains and ocean of North Carolina, USA, but not much nearby that is more interesting than the normal. Someday I will take the time to find something of interest to video in a place where drones are not banned.

 

[maknak]

I hope all advice's will play good and i will have a chance to record more.
I am saying exactly the same thing to people in my town - they are living here for 50-80 years and none of them saw towns castle from the the sky. Once i am publishing some local video - its always have positive comments with ohhh and ahh

 

[maknak]

Hey - made cleaning as you advised. found few black bits. Don't know if that could cause some interference but i did this:
1. Cleaned shaft as you advised.
2. Resolded connections ABC - i reduced amount of solder that i have used previously and this time i was using Flux.
AND IT IS FLYING AGIAN
Thank you for your help.
Yeeha
I do not know which thing worked better but it is flying so that could be ether of these two.
Really appreciated.

 

[WTFDproject]

[QUOTE" IT IS FLYING AGIAN [/QUOTE]

WONDERFUL!! Good job getting the bird back in the air.

May you have many good flights and more great video!