Help, electric scooter wheel not turning!!!

[Judah]

I have an old QMWHEEL H6 electric scooter that stopped working about a year ago. It would not turn the wheel so I tried a few things then gave up. A year later (a week ago) I ordered a new ESC and controller unit. It seemed to work fine until I re-assembled it and tried to use it. The motor felt like it had verry high power when off the ground but then when I stepped on it the motor had almost none and stopped. I could then feel the motor spinning inside the wheel but the tire would not turn at all.(by the way this is a non-geared brushless BLDC motor)

How do I fix this?

Thanks

 

[amberwolf]

If it's a direct drive motor, it can't actually spin the motor without spinning the wheel.

But if the magnets came unglued (usually from overheating, sometimes from corrosion from water intrusion) they could be spun around inside the rotor backing ring if that's being held in place by a load on the wheel.


If the original problem was overloading / overheating that blew up the controller (shorted or open FETs), that would make sense, as the motor could have overheated before the controller failed.

 

[Judah]

Thanks, but the wheel stopped working way before the controller did, I blew the ESC and controller trying to fix the wheel. So do you think that I should replace the wheel?

 

[amberwolf]

To know for sure, you'd have to open it up. If you take the side cover off and can see the magnets, you could load the wheel down and attempt to throttle up just a little and see if the magnets try to scoot around, wiggle, etc. Or if you have a tough plastic tool with a thin edge (like those wedges used to open phones up for battery fixes) you could try to move / lift a magnet, but if they are actually glued down and you pry hard you can break them.

Or you can see what else might be wrong in there.

 

[Judah]

Thanks, will do.

 

[Dui ni shuo de dui]

Yes, what you describe looks a lto like what happened to my motor.
There was a problem with the glue and the magnets came loose, see here: Ninja 250 "Clone" Made in China

You don't need any special tool to remove the magnets, you just need to push them/slide them to the side and then you will be able lift them up very easily.

Be very careful when you store them, they have some crazy power. I suggest not putting more than 4 or 5 magnets together, and place the 5 magnets stacks very far apart from each other. If they manage to attract each other they will snap and break, plus they will crush anything that's in between, including your fingers. Don't underestimate these magnets, especially when there's a few ones grouped together.

I used a high temperature resistant 2 component epoxy glue to put them back together, so far it seems to work fine. Don't forget to clean the surfaces with acetone or alcohol before applying the glue.
Also, don't forget to note the polarity/orientation of the magnets before you remove them.

It is better if you can find a big bearing extractor to open the motor, it makes opening the motor a whole lot easier.