Hub motor stopped working. Help!

Y

ymd

100 mW
Joined
Aug 3, 2017
Messages
40
Location
Bay Area, California
Yesterday wile riding home from work my bike hub motor started making noise. I stopped to check. All the wires were in place. Checked the throttle. The motor ran a bit and stopped entirely. Now it makes just a noise and does not run at all either in pedal assist or throttle. Needless to say, I had to pedal my heavy bike over the next 6 miles to reach home. My motor is MAC. I have run over 6000 miles on this motor.

Any advice or help in troubleshooting will be greatly appreciated.
 
That is quite a bit of mileage. I would say you probably are ready for a new motor. But it could also be the controller.
 
You looked at all the wires from the axle to to the controller to see if they were not frayed or damaged?
You've spun the motor without any power and no noise?
What have you changed in the last month? Was there a new battery, new voltage, new controller, new throttle?
 
Stator to winding short, or maybe a hall error and you cooked it continuing to run.
 
Based on the information provided, I'm almost certain that the problem is either mechanical or electrical, but could be both.

What does the noise sound like?
 
I looked at all wires and nothing was obviously frayed. There’s no noise when motor is spun with no power. I have not changed anything over nearly a year. I had replaced motor last year under warranty from EM3ev. The noise sounds like a Tesla car passing by. In fact when I first heard the noise I thought a Tesla car was passing by.
markz said:
You looked at all the wires from the axle to to the controller to see if they were not frayed or damaged?
You've spun the motor without any power and no noise?
What have you changed in the last month? Was there a new battery, new voltage, new controller, new throttle?
Click to expand...
 
If you have a multimeter it should be fairly easy to check for winding shorts, and with a bit more effort you can test the hall sensors.

You'll probably have to turn the motor backwards to do the hall test, as the clutch in the motor will prevent the wheel moving forward from turning the motor.
 
I am guessing a Hall sensor problem one way or another, but this is what you need to do to find out.

As instructed carefully check all your wiring for disconnections and shorting.

With the motor wires plugged in and the power on, does the motor spin freely, or does it cogg?
With the motor wires unplugged does the motor spin freely or does it cogg?

Do you have a multi-meter? If the answer is no, then get one.

If yes, go here and test your halls: https://www.ebikes.ca/documents/HallSensorTestingFinal.pdf

:D :bolt:
 
ymd said:
The noise sounds like a Tesla car passing by. In fact when I first heard the noise I thought a Tesla car was passing by.
Click to expand...

OK, so now when you give it throttle, it whirs, but the wheel doesn't spin? When the noise first happened, before it crapped out, was that the same kind of noise? No crunchy or grinding sounds?
 
ymd said:
had replaced motor last year under warranty from EM3ev.
Click to expand...
So the 6000 miles is just one year's mileage?


The noise sounds like a Tesla car passing by. In fact when I first heard the noise I thought a Tesla car was passing by.
Click to expand...
Like a motor speeding up and whizzing inside the case?

That sounds like the clutch has failed.

To test this put the bike upside down so the motor wheel is off ground and hand-spin it backwards. There should be significant resistance.

If there is none, the clutch is probably not passing torque into or out of the motor.

Additionally, you can test while bike is upside down by running the throttle at full. If the clutch is not working correctly, it may still spin the wheel very very slightly forward under this condition.

EM3EV carries new clutch/gear assemblies.
 
I checked the hall sensors. It seems they are working. I connected the multimeter between black to yellow, green and blue wires while spinning the wheel forward and the voltage varies between 0 to 5V in all cases.

I checked all the wires. Found the yellow wire on the hall sensor connector was loose. Even when the wire is securely connected, the problem remains.

With motor wires plugged in and power on, motor spins while making the same noise when I pedal. It does not spin fully freely. There is some resistance. When I stop spinning the pedal, the wheel runs about 1 or 2 revolutions and stops.

With the motor wires unplugged, the behavior is same except there is no noise. There is the same resistance. To ensure the brake is not touching, completely loosened brake cable. The resistance is still there both when the motor is powered and not powered.(Is this what you mean by "cogg"?)
e-beach said:
I am guessing a Hall sensor problem one way or another, but this is what you need to do to find out.

As instructed carefully check all your wiring for disconnections and shorting.

With the motor wires plugged in and the power on, does the motor spin freely, or does it cogg?
With the motor wires unplugged does the motor spin freely or does it cogg?

Do you have a multi-meter? If the answer is no, then get one.

If yes, go here and test your halls: https://www.ebikes.ca/documents/HallSensorTestingFinal.pdf

:D :bolt:
Click to expand...
 


So the 6000 miles is just one year's mileage?
Click to expand...

Yes, the 6000 miles is all in one year. I commute everyday 18 miles each way. I have hardly used my car in the last over 1 1/2 years. Sometimes I take the bus.

The noise sounds like a Tesla car passing by. In fact when I first heard the noise I thought a Tesla car was passing by.
Click to expand...
Like a motor speeding up and whizzing inside the case?
Click to expand...
Yes, somewhat sounds like that. Here is how it sounds like: https://photos.app.goo.gl/WsLtT3F32cz5pbSL7

That sounds like the clutch has failed.

To test this put the bike upside down so the motor wheel is off ground and hand-spin it backwards. There should be significant resistance.

If there is none, the clutch is probably not passing torque into or out of the motor.

Additionally, you can test while bike is upside down by running the throttle at full. If the clutch is not working correctly, it may still spin the wheel very very slightly forward under this condition.
Click to expand...
I put the bike upside down and tried spinning the motor wheel backwards. There was significant resistance.

When I tried to run the the throttle at full, the wheel turns imperceptibly. You can see the response in the attached video link above.

Does it mean the clutch is not working correctly?

EM3EV carries new clutch/gear assemblies.
Click to expand...

I have placed an order for the clutch and gear assemblies from EM3EV. What kind of circlip pliers and gear puller would I need?

Thank you very much for your help.
 
E-HP said:
ymd said:
The noise sounds like a Tesla car passing by. In fact when I first heard the noise I thought a Tesla car was passing by.
Click to expand...

OK, so now when you give it throttle, it whirs, but the wheel doesn't spin? When the noise first happened, before it crapped out, was that the same kind of noise? No crunchy or grinding sounds?
Click to expand...

When I give it throttle, this is how the motor sounds: https://photos.app.goo.gl/WsLtT3F32cz5pbSL7 . The wheel does not spin.

Just before the present situation, there was crunchy noise. I was going on a rough road and though it was road noise for a moment. That is when I stopped to investigate. After going a bit farther, it stopped completely engaging the wheel and gave the noise in the above video.
 
ymd said:
E-HP said:
ymd said:
The noise sounds like a Tesla car passing by. In fact when I first heard the noise I thought a Tesla car was passing by.
Click to expand...

OK, so now when you give it throttle, it whirs, but the wheel doesn't spin? When the noise first happened, before it crapped out, was that the same kind of noise? No crunchy or grinding sounds?
Click to expand...

When I give it throttle, this is how the motor sounds: https://photos.app.goo.gl/WsLtT3F32cz5pbSL7 . The wheel does not spin.

Just before the present situation, there was crunchy noise. I was going on a rough road and though it was road noise for a moment. That is when I stopped to investigate. After going a bit farther, it stopped completely engaging the wheel and gave the noise in the above video.
Click to expand...

Sounds like you bought parts to fix the clutch. I'm guessing that'll do it.
 
Yep, time to open your motor. Have you ever opened an e-bike motor before?
 
e-beach said:
Yep, time to open your motor. Have you ever opened an e-bike motor before?
Click to expand...

The last time I opened the motor, I did not know how to go about it and struggled as I did not have the right tools. This time I have ordered a gear puller and circlip pliers. Would I need anything else. Is there a video on how to open the motor?
 
FYI there is no need for a gear puller, but it is helpful.
Just take off the bolts of the cover plate, make sure that the axle bolts are off.
Put the hub motor wheel on the axle, and press down on the rim.


I would not do it that way, if at all possible. The wood is a great idea, but pounding it like that I would try something else before resorting to that. If the cover plate is really that stuck then I guess so. I've always been able to get the cover plates off by slightly doing that, or using a knee to hold down one side, and using my hand for the other side, or my knee but making sure to not damage the rim.
https://youtu.be/0LErhKbWJlE?t=50


ymd said:
e-beach said:
Yep, time to open your motor. Have you ever opened an e-bike motor before?
Click to expand...

The last time I opened the motor, I did not know how to go about it and struggled as I did not have the right tools. This time I have ordered a gear puller and circlip pliers. Would I need anything else. Is there a video on how to open the motor?
Click to expand...
 
Thank you all for your help, I finally got to work on my hub motor. The gear teeth on the plastic gears were completely worn out as can be seen in the attached photo. I replaced the gears and clutch and put everything back together and it seemed to work well.

Today as I rode my bike to work, after riding for about 4 miles, the motor suddenly stopped with no response. When I tried to throttle, I could see on the CycleAnalyst that the motor was drawing power . Then even that (indication of power being drawn) stopped. Is the motor dead completely? Could some debris from the worn out gears gotten into the motor that caused its failure? I spent a lot of time cleaning up the inside of the hub as the plastic was stuck in all the teeth of the metal hub. I removed only the debris sticking out of the motor windings. Could it be possible that there was some debris in the motor winding that I missed which could have caused this problem? Would it be better to replace the whole wheel with the hub motor with a new one and avoid the hassle of going through the trouble of replacing parts? I depend on this bike for my commute. What would you suggest?
IMG_2930.jpg
IMG_2933.JPG
 
Wow, what a drag..... :(

Ok, to rule out any physical problem, disconnect your battery. Disconnect your phase wires again. Make sure the phase wires are not touching each other and spin the wheel. Does it spin freely? Or, does it drag?
 
I checked the phase wires with a multimeter. There is continuity between the phase wires (low resistance). When two phase wires are touching there is significant drag when rotated backwards, I also checked the voltage on the phase wires (between Black-Yellow, Black-Green and Black-Blue. The voltage in all 3 cases is 5V and does not change when the wheel is rotated slowly. Does it mean all 3 hall sensors are bad? If so, should I try fixing them or replace the motor?

e-beach said:
Wow, what a drag..... :(

Ok, to rule out any physical problem, disconnect your battery. Disconnect your phase wires again. Make sure the phase wires are not touching each other and spin the wheel. Does it spin freely? Or, does it drag?
Click to expand...
 
A couple of things:

1: what happens when your phase wires are disconnected and not touching each other? Does the motor spin freely? Or is their drag? If drag, how much drag.

2: The hall wires are not phase wires. To test the hall wires follow these directions.
https://www.ebikes.ca/documents/HallSensorTestingFinal.pdf

Let us know how it goes.

:D :bolt:
 
e-beach said:
A couple of things:

1: what happens when your phase wires are disconnected and not touching each other? Does the motor spin freely? Or is their drag? If drag, how much drag.

When the phase wires are not touching, the motor spins freely with just a slight drag (just as much as when a brake pad is touching the disc). When the phase wires are touching, it is very hard to rotate the wheel.

2: The hall wires are not phase wires. To test the hall wires follow these directions. https://www.ebikes.ca/documents/HallSensorTestingFinal.pdf
I think I tested the hall sensors correctly. I plugged the multimeter probes into the hall sensor connectors and verified that the voltage does not change when the wheel is rotated. I had replaced the hall sensor connector when I changed the gears. The fact that the bike ran for a few miles after this change makes me think I did not mess up the connections when I made the connector change. Could changing the connector might be a factor for the motor not responding? Even now when I apply the throttle, there is a momentary surge in power to the motor and just a slight movement of the wheel.


Let us know how it goes.

:D :bolt:
Click to expand...
 
ymd said:
...... I also checked the voltage on the phase wires (between Black-Yellow, Black-Green and Black-Blue. The voltage in all 3 cases is 5V and does not change when the wheel is rotated slowly. Does it mean all 3 hall sensors are bad? .......
Click to expand...

As I said, phase wires and Hall wired are different. If you properly checked the Hall sensors and the are all reading 5v, and do not latch between 0 and 5v, then they are all blown. But I will ask you one more time. Did you follow these direction? https://www.ebikes.ca/documents/HallSensorTestingFinal.pdf

If so, you need to replace all the Halls, or get a new motor. Since you don't seem to be 100% on what is what in your motor, I would recommend getting another motor that matches your battery pack and controller. A motor like the one you have is a good place to start.

Put the one you have on the shelf until you are better versed at what to do and then sometime in the future fix it as a backup.

:D :bolt:
 
Yes, I did follow the directions in the link that you give me: https://www.ebikes.ca/documents/HallSensorTestingFinal.pdf. The phase wires are 3 thick wires that are separately connected to the motor unlike the hall sensors that are connected through a single connector. Have I got the difference between phase wires and Hall wiring correct? I see that in the previous post I said voltage of "phase wires" where I should have said "Hall wires". Sorry for the confusion.

Thank you for your help and suggestions. I will get a new motor. I am also thinking of getting a fully built wheel with a motor to ensure that I can surely get back on my ebike as soon as possible. I might tinker with the hall sensors as a side project. Where do I buy Hall sensors? Is there a reliable video that shows how to replace the Hall sensors?
e-beach said:
ymd said:
...... I also checked the voltage on the phase wires (between Black-Yellow, Black-Green and Black-Blue. The voltage in all 3 cases is 5V and does not change when the wheel is rotated slowly. Does it mean all 3 hall sensors are bad? .......
Click to expand...

As I said, phase wires and Hall wired are different. If you properly checked the Hall sensors and the are all reading 5v, and do not latch between 0 and 5v, then they are all blown. But I will ask you one more time. Did you follow these direction? https://www.ebikes.ca/documents/HallSensorTestingFinal.pdf

If so, you need to replace all the Halls, or get a new motor. Since you don't seem to be 100% on what is what in your motor, I would recommend getting another motor that matches your battery pack and controller. A motor like the one you have is a good place to start.

Put the one you have on the shelf until you are better versed at what to do and then sometime in the future fix it as a backup.

:D :bolt:
Click to expand...
 
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