Help diagnosing motor problem

[Pontation]

Hi,

I've been cruising along with my board about 5 km almost every day since november and for the most part it has been working surprisingly well considering that it's my first build. Recently though I started having some problems. When I ride, the motor sometimes gives off a bad noise and loses most of the torque. You can hear it in the video here: https://www.youtube.com/watch?v=AkOJ1gilGKY(sorry for the potato video quality)

At the moment of the video, the battery cells were all in the range of 3.89-3.92V, but I have also experienced this with the battery fully charged. One interesting piece of information is that this doesn't happen unless I stand on the board so I checked to make sure that it wasn't just the belt being worn but even replacing it didn't fix the problem. It seemed to work at first but after a day the problem was back. I have checked all wires coming out the esc, they all seemed fine upon close inspection.

I am suspecting that the motor is the problem. There have been tiny amounts of splash of dirty water from the road every now and then, and my fear is that this is the result of enough buildup. Here are a couple of links to photos of the motor:
https://drive.google.com/file/d/0Bw0yDtRk0AmPSURVTHVXT2hOSlU/view?usp=sharing
https://drive.google.com/file/d/0Bw0yDtRk0AmPQ0hTSGRpMk5zSW8/view?usp=sharing

As you can see there is some black residue in the top which look almost like burned plastic (probably dried dirt?!) on the coils. Could this be my problem or do you think that the problem is something else? Is it possible to clean this up to test and if so how would I dismantle the motor to get access, and are there any special cleaning products needed? Any tips, recommendations, links would be much appreciated.

This is my build:
Motor: Alien 5065 Outrunner brushless motor 270KV 2200W
ESC: TrackStar 150A GenII 1/8th Scale Sensored Brushless Car ESC
Battery: (2 in series) ZIPPY Flightmax 5000mAh 3S1P 25C
RxTx: Quanum 2.4Ghz 3ch Pistol Grip Tx & Rx System

Thanks,
Pontus

 

[Montiey]

Does the motor spin well without a load? You many want to take it off the mount to test it better. It could also be a timing issue. If the ESC supports it, try changing the timing.

 

[astilwell611]

Don't really know what your problem could be but just wanted to say I doubt it is any kind of build up. I ride on a campus where there is constant construction, so I'm always riding through gravel, dirt, and other crap. Also I ride in the rain and wet quite a bit. I have yet to have any problems out of my motor and it has been half a year.

 

[psychotiller]

Best way to test it would be to hook it up to another ESC. You'll either confirm you have a motor issue or an issue with your ESC.

 

[Pontation]

Thanks everyone for the replies, great input!

Does the motor spin well without a load? You many want to take it off the mount to test it better. It could also be a timing issue. If t

Yes, it spins well and without noise if I run it without standing on the board. Being a beginner at this I don't really know what is timing sensitive in this system but I will do some research

Best way to test it would be to hook it up to another ESC. You'll either confirm you have a motor issue or an issue with your ESC.

Yeah the good old process of elimination will probably be the way forward. I do have a spare esc but unfortunately no extra RC bullet connectors. Will try to figure something out.

 

[Pontation]

I finally got to testing with a new ESC of the same model as the previous one. Unfortunately the problem remains. At this point I'm hard pressed to think it could be anything other than the motor. Is there any way to fix a motor which behaves like this or is it simply time to buy a new motor? Can it really be normal wear and tear that causes this? I feel like it should have lasted longer than 3-4 months, but maybe I'm expecting too much from a 60£ motor!?

 

[torqueboards]

Motors should last a long time. I've had motors last over 2k miles. Perhaps, you got a lemon motor and/or it was damaged due to riding it. If you overheat the motor mount to the point of damaging it.

Did you notice if it got overheated? Sometimes the wires can get cut too.

 

[Pontation]

I didn't notice any overheating, I guess I can't be sure it didn't happen though. What's a lemon motor? All I get when googling it is actual lemons as batteries
I'm currently in talks with alienpowersystems and it seems that it may be that a hub has gotten detached from the stator. Will update with more information if we get it solved.

 

[torqueboards]

Lemon just means bad... Bad motor. It's not likely though. Could have gotten damaged somehow.