Did I just break my motor?

Hi guys,

just came back from a relaxing 10km Sunday evening run and plugged my board into the charger. I checked the belt and noticed that there is a noticeable wobble in the rotor of my SK3 :scream: Is that normal wear or did I somehow damage my motor? Can this be fixed?

Here is a video of the wobble: https://www.youtube.com/watch?v=JBN2WIEaDwk


The video is too short to see what’s wobbly

@Michaelinvegas please look at the space between rotor can and mount - the spacing changes. If you need a longer video I can record one but it is just the same thing happening over and over again (maybe I should put this in a gif ;))

check if the e-clip is still on the shaft.

circlip (is that what you meant with e-clip?) is still there. I am more worried that it might be a bearing that is damaged. During my ride I did NOT notice anything weird - so not sure if this issue is actually a big problem or just “cosmetic” or even normal for outrunner motors.

You can’t see much in video so quick. Do u hear rubbing inside when turning by hand…how bout when going really fast? Could be unbalanced and get worse at speed maybe the little screws holding the rotor to shaft in back of motor are loose?

Well f*ck - one of the three screws actually broke. That means I can not just replace it with a new one. Anybody has an idea of what to do now?

Ok so… It was a loose motor due to the bolt?

I guess so - i just don’t know how to fix it. The screw is tiny so a screw extractor will probably not work.


1 of three?

Yeah you see those small black screws close to the shaft? One of those is the one I hold in my hands in the picture. It is shorter than the other two and can’t be put back in because the thread is blocked by the remaining piece.

What I’m asking is…What happened to the fourth bolt?

There is no fourth. http://www.hobbyking.com/hobbyking/store/catalog/bearing.jpg

It was not one of the bolts holding the motor to the mount but one of the three that holds the actual motor together.

Ohhh … I c duh

Sorry I was looking at the motor mount holes

How the heck did that break…

I’ll have to take a look when I get home …I have the same motor not mounted yet

Regardless you’ll need to take apart the motor

Yeah will try to get some circlip pliers tomorrow.

Ok so this thing is a pain to open. Stripped one of the 4 screws on the side holding the rotor and stator together. Also bent some of the lid edges while trying to pry the motor apart. Then used a 1.5mm drill and EZout to remove what was remaining of the broken screw. Now I am scared however that metal dust got between the coils. Will see if it moves once I get home today. Is there a test i can do to make sure there is no damaging metal inside the motor?

Get the little circlip off, open it up, and clean off the magnets which will attract iron. If u spin it and hear grinding it’s in there. Or blast it out with compressor. Don’t bend the rotor

I had it open - don’t want to go through this again. Thus I used compressed air to remove dust and particels. However when I hold it close to my ear I can still hear some faint grinding noises - can that be a bearing or somethig else? How loud would grinding metal be?