Hub motor swap from Bafang to MXUS

[Binlo]

No.
You test via the controller if it has a hall wire block by poking the probes in to the rear.

Okay thanks, I think I understand what I need to do now

 

[Binlo]

Hall sensors work independently from the load on the motor. They're on a completely different circuit to the motor power, so are not influenced by power or speed. The only logical fault for a hall sensor with your symptoms would be something like a wire not tied down properly and it's rubbed on the motor and worn through its insulation, which probably wouldn't show during testing if the motor always starts. It's much more likely that your problem is related to the phase wires, but that would be very unusual, except for faulty connections or damaged cable.

Okay, I dont believe I have damaged wire from the motor but not ruling that out and will need to check. But then if that was the case, I would have expected the motor not to work at all etc, only seems to cause issues when the motor needs to work harder ... I think the motor heats up and then plays up.

 

[WheezyRider]

Yes, it frees without any issues etc and no noises at all. When the motor starts to play up the current peaks out at 5 bars on display and motor does not spin, or just overspins internally as the wheel does not turn. Cannot even perform walk mode.

Yes , that is a good idea but for now I will stay with the new motor and if I ever do change the controller then will give this a test to see what happens. I think bottom line is I may have over cooked the motor or its windings when they heat up etc.

So the motor spins, but the wheel doesn't go round?

That could be a clutch problem.

 

[Binlo]

So the motor spins, but the wheel doesn't go round?

That could be a clutch problem.

Where is the clutch inside the motor? Is this easy to replace?

And if that is the issue , would you expect the motor to work say 5 miles without any issues and then an incline or load comes along motor cuts out but trying to work as you can see it soaking up the current.

Then shutting it all down say 10mins, I can do like another 5 miles , it is just hit and miss ???

 

[WheezyRider]

Thanks, the bike is so much fun. The motor is from 250w - 350w, so are you saying that the motor will be still working at 350w even though I can limit the speed down to 15.5MPH , the legal speed for ebikes in the UK. The motor has no badging of power, just says MXUS on the hub and model number on the side. Nothing about power output.

Okay I will do that next time I have the controller out again.
Thanks for all the assistance

Yes, the motor will still run at its rated power up to 15.5 mph.

Probably best for someone else who knows that MXUS motor of yours inside out to comment on the exact specs of your particular model. At least it doesn't say "350W" on the outside

 

[WheezyRider]

Where is the clutch inside the motor? Is this easy to replace?

And if that is the issue , would you expect the motor to work say 5 miles without any issues and then an incline or load comes along motor cuts out but trying to work as you can see it soaking up the current.

Then shutting it all down say 10mins, I can do like another 5 miles , it is just hit and miss ???

When you say the motor cuts out, is it spinning inside the hub?

The clutch is a replaceable item. Normally when they go, they seize and so it doesn't disengage, but sometimes they can do odd things if they have not been lubricated properly.

 

[Binlo]

Yes, the motor will still run at its rated power up to 15.5 mph.

Probably best for someone else who knows that MXUS motor of yours inside out to comment on the exact specs of your particular model. At least it doesn't say "350W" on the outside

This is the spec from there website, not sure if it helps in anyway .. but I do think it is much smoother operation wise then the cheap Bafang 250 10D model .. which is the lowest entry one they do ..

Technical Parameters	Drawing​
Gear motor Rated Voltage(V):24/36/48 Rated Power(W):250-350 Wheelsize(inch):16-28 Rated Speed(km/h):25-40 Weight(KG):3.5 Open size(mm):135 Cable location:shaft center right Color:Silver/Black Brake type:V brake/Disc brake See this link , last image gives more spec for motor ZOOMPOWER 36v350w 48v 500w xf15f xf15r ebike kit Electric Bike Conversion kit Motor Wheel mxus Brand (48V 500W Front Black 700C): Amazon.ca: Sports & Outdoors ZOOMPOWER 36v350w 48v 500w xf15f xf15r ebike kit Electric Bike Conversion kit Motor Wheel mxus Brand (48V 500W Front Black 700C): Amazon.ca: Sports & Outdoors www.amazon.ca

 

[Binlo]

When you say the motor cuts out, is it spinning inside the hub?

The clutch is a replaceable item. Normally when they go, they seize and so it doesn't disengage, but sometimes they can do odd things if they have not been lubricated properly.

Yes, that is exactly it .. it feels like the motor is just free spinning inside and then you see on the display full current usage of 5 bars. The wheel does not move, even if you lift the back of the bike up .. Then after that 30sec spinning it just grinds to a halt and needs to be powered off for 10mins or so before life kicks back in again ... and a repeat again

 

[WheezyRider]

Yes, that is exactly it .. it feels like the motor is just free spinning inside and then you see on the display full current usage of 5 bars. The wheel does not move, even if you lift the back of the bike up .. Then after that 30sec spinning it just grinds to a halt and needs to be powered off for 10mins or so before life kicks back in again ... and a repeat again

Does sound like a problem with the clutch or the nylon cogs not engaging properly.

 

[vfr400]

Does sound like a problem with the clutch or the nylon cogs not engaging properly.

There would be virtually no current if the clutch was slipping or if the gears were stripped. Lift you wheel off the ground and see how much current you can get.

 

[Binlo]

There would be virtually no current if the clutch was slipping or if the gears were stripped. Lift you wheel off the ground and see how much current you can get.

I think I did this, and the current was the same, maxed out at 5 bars. I am going to see if I can upload this video that I took to show you the effect

This is me trying to use walk mode , and you will see current jumps up to max but bike does not move etc even though it says 3.6mph on display
https://drive.google.com/file/d/1w4RExTbzQDHPkZuuBX3btjKVrdnijd7F/view?usp=drivesdk

This one shows the Motor fault symbol intermittent flashing up and then current max out towards the end, btw, when that symbol comes up you can tell the motor has stopped as the bikes very heavy and you can tell it is unassisted then
https://drive.google.com/file/d/1wHDRJ-KgArv_uSOpfPx64KxR9EAPn8rC/view?usp=drivesdk

I just realised access was denied to these links, it's now open to play.

 

[vfr400]

I think I did this, and the current was the same, maxed out at 5 bars. I am going to see if I can upload this video that I took to show you the effect

This is me trying to use walk mode , and you will see current jumps up to max but bike does not move etc even though it says 3.6mph on display
https://drive.google.com/file/d/1w4RExTbzQDHPkZuuBX3btjKVrdnijd7F/view?usp=drivesdk

This one shows the Motor fault symbol intermittent flashing up and then current max out towards the end, btw, when that symbol comes up you can tell the motor has stopped as the bikes very heavy and you can tell it is unassisted then
https://drive.google.com/file/d/1wHDRJ-KgArv_uSOpfPx64KxR9EAPn8rC/view?usp=drivesdk

The reason you're getting high current is because the controller has lost sync with the motor. In that case the motor is effectively stalled.

When the motor wheel is off the ground and working properly, the most current you can get is about 1 amp, except it will be a bit more while accelerating.

 

[Binlo]

The reason you're getting high current is because the controller has lost sync with the motor. In that case the motor is effectively stalled.

When the motor wheel is off the ground and working properly, the most current you can get is about 1 amp, except it will be a bit more while accelerating.

Okay sounds feasible , what would cause that stalling issue then ? As I know the controller is fine with the other motor , bike is going well and have done over 40 miles with no issues

 

[vfr400]

Okay sounds feasible , what would cause that stalling issue then ? As I know the controller is fine with the other motor , bike is going well and have done over 40 miles with no issues

I gave all the suggestions in my previous posts.

 

[Binlo]

I gave all the suggestions in my previous posts.

Okay thanks, I will review your previous posts.

As you mentioned something about controlled out of sync with motor, I thought this was a new issue that has not been discussed before?

 

[vfr400]

Okay thanks, I will review your previous posts.

As you mentioned something about controlled out of sync with motor, I thought this was a new issue that has not been discussed before?

Sorry, I was thinking of another thread.

Reasons for losing sync:
1. Wrong setting in the LCD (only affects some controllers that have settings for phase angle and timing). If you didn't change anything, that's not likely.
2. Bad phase wire connection.
3. Faulty mosfet in the controller.
4. Faulty hall sensor or hall sensor connection. this normally gives an error code on the LCD, so not that likely
5. Incompatible controller. Not all controllers work with all motors. If you didn't change the controller and it worked before, that's not likely.

If the motor was working and then some time later it started losing sync, it would almost certainly be 2 or 3, but your controller works with the new motor, so that means 2 is a strong favourite. If all tests and inspections from the outside of the motor don't reveal anything, you have to open it to see what's going on inside.

 

[WheezyRider]

If the motor is spinning internally, but the wheel is not moving at all, then the mechanical connection from the spinning magnet cage is not engaging with the outer hub.

As has been said, if the motor is spinning uninhibited by anything at full speed, then the current it should draw would only be around 1A. If the controller is reporting full current, this could be the controller misreporting the current flow, or the motor is not spinning at full speed and it is encountering resistance from something inside, but not turning the wheel.

Have you got hold of a power meter yet to see what the real current flow to the motor is?

 

[WheezyRider]

This isn't a Bafang motor, but they are all quite similar, and should give you an idea of what's going on inside. The coil windings are fixed. A magnet cage spins around the coils at quite a high speed. This engages a clutch, which engages the nylon cogs with the outer cog on the hub. You can see how small the gaps are between the coils and the magnets and the magnet cage and the hub itself.

 

[Binlo]

It

If the motor is spinning internally, but the wheel is not moving at all, then the mechanical connection from the spinning magnet cage is not engaging with the outer hub.

As has been said, if the motor is spinning uninhibited by anything at full speed, then the current it should draw would only be around 1A. If the controller is reporting full current, this could be the controller misreporting the current flow, or the motor is not spinning at full speed and it is encountering resistance from something inside, but not turning the wheel.

Have you got hold of a power meter yet to see what the real current flow to the motor is?

It only spins internally for about 30 sec or so before the motor dies completely and then have to wait 10 mins before you can cycle again on assistance.

No not yet have not had chance to open the motor or do any further tests ,as bike is now working perfectly with new motor however have noticed alot more battery consumption now ..

 

[Binlo]

This isn't a Bafang motor, but they are all quite similar, and should give you an idea of what's going on inside. The coil windings are fixed. A magnet cage spins around the coils at quite a high speed. This engages a clutch, which engages the nylon cogs with the outer cog on the hub. You can see how small the gaps are between the coils and the magnets and the magnet cage and the hub itself.

Okay great at least I know what the motor will kind of look like now from inside.

Thanks for all your time and help