*resolved* Loud knocking noise coming from Brand New MP - then dies (again)

[Cornelius]

the wheel has ground to a halt like it's being held in place by the magnets in the wheel - even with the battery disconnected.

Sounds like shorted phases?
Either some Fets has shorted, or phase wires has shorted due to wear against the housing (which would explain the ticking sound? )

[Bikemad]

To add insult to injury, the motor has now stopped responding to any input and the wheel has ground to a halt like it's being held in place by the magnets in the wheel - even with the battery disconnected. The horn or any of the controller reset options are not working either.

What do I do with this thing now?

Magzy, try disconnecting the three thick phase wires (Yellow, Blue and Green) from the controller and see if the wheel is still tight. If the wheel moves freely with the wires disconnected, it will definitely be the controller that has failed. However, if the wheel is still tight, it will be a mechanical fault, and the wheel will need to be dismantled to locate the cause of the problem.

I'm pretty certain it will be a couple of FETs that will have failed in a shorted state inside the controller, but I'm not sure as to why this happens. If this failure has been caused by a faulty component within the controller, it should just be a simple matter of replacing the faulty controller unit. 
But if it has been caused by a faulty hall sensor, it could well happen again with a replacement controller.

Please let us know what happens.

Alan
 
 

[GM Brazil]

I lost my bet again

[Cornelius]

Bikemad:
I wrote earlier that he probably have no option but to open the motor, because I assume he has a MP with internal controller...

[Magzy]

the wheel has ground to a halt like it's being held in place by the magnets in the wheel - even with the battery disconnected.

Sounds like shorted phases?
Either some Fets has shorted, or phase wires has shorted due to wear against the housing (which would explain the ticking sound? )

Thanks for this info,

So, just to be clear, where are the Fets? and where are the phase wires? (in the controller or in the motor?)

Yes, I have an external controller.

[Magzy]

ok Tom from goldenmotor got back super quick (thanks tom and Gary from GM Canada)

He seems to think that the noise is most certainly the coming from the bearings. (maybe he knows they're crap?)

So, in anticipation of me opening the motor (which any reasonable biped would not be happy about having to do on a brand new new motor) and finding out that the bearings are indeed shat, what is the part number for the MP bearings? how many sets are there? One for each side? or just one set?

from my research on looking on this forum et-al, I see these as contenders: Model number "6202 2RS" http://australia.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=4090417

Can anyone confirm these are the correct bearings for the MP??

I don't mind fixing this myself if it means getting on the road quicker.

[Cornelius]

Oh, ok.

The Fets (Field Effect Transistor) are inside the controller, and are - simply said - managing the big currents between the battery and motor.

The phase wires are the 3 thick wires from the controller to the motor.
If you disconnect those 3 wires from the controller and the wheel then turns freely, one or more of the fets in the controller are broken. (for non-electronic-guys; the controller are broken )
If the wheel still are locked up without the 3 phase wires connected, there's a chance that either the phase wires are shorted/damaged; on the way down or inside the motor, or in worst case - one or more of the coils inside the motor has become loose and gotten shorted due to wear against the motor housing....

At least; this is my theories...

[Magzy]

Oh, ok.

The Fets (Field Effect Transistor) are inside the controller, and are - simply said - managing the big currents between the battery and motor.

The phase wires are the 3 thick wires from the controller to the motor.
If you disconnect those 3 wires from the controller and the wheel then turns freely, one or more of the fets in the controller are broken. (for non-electronic-guys; the controller are broken )
If the wheel still are locked up without the 3 phase wires connected, there's a chance that either the phase wires are shorted/damaged; on the way down or inside the motor, or in worst case - one or more of the coils inside the motor has become loose and gotten shorted due to wear against the motor housing....

At least; this is my theories...

Thanks for this, it makes sense now. I'll be opening the motor tonight /tomorrow and having a look.

I'll get back with the findings.

Magz

[Magzy]

Right, so I remove the three phase wires -- blue, green and yellow, and the wheel moves freely. Reconnecting them renders the wheel to become stuck again regardless of whether the battery is connected or not.

so sounds like the controller is fried?

[Bikemad]

Magzy, email Tom again and explain what you have done, and ask if he can get a replacement controller sent direct to you from a local dealer to save time.

Alan

[Cornelius]

Magzy: it sounds like you have found the reason for the bike's no-go...

But what about the ticking sound? Could it be the reason for the controller failing? That's what worries me...  

Edit:
Since you kinda' have a Go for opening the motor from Tom, I would open it to inspect the innards. Then you could check the bearings and inspect the coils and verify that none of the wires are able to touch the rotating parts of the housing.

But that's me... Kind of suspicious that you hear a noise from the motor, and not long after the controller blows... :-/

[Bikemad]

But what about the ticking sound? Could it be the reason for the controller failing? That's what worries me... 

Cornelius, that concerned me too:

I'm pretty certain it will be a couple of FETs that will have failed in a shorted state inside the controller, but I'm not sure as to why this happens. If this failure has been caused by a faulty component within the controller, it should just be a simple matter of replacing the faulty controller unit. 
But if it has been caused by a faulty hall sensor, it could well happen again with a replacement controller.

I don't know if it's possible for a hall sensor to have been fitted facing the wrong way, but if that were the case, it might cause the polarity to be switched the wrong way on the corresponding phase wire, which could account for the loud knocking/ticking noise.

I'm certainly not convinced there is a bearing problem, and I would wait and see how the motor sounds with the replacement controller fitted before doing anything else to the motor.

If the controller was responsible for its own failure, a new controller should completely cure the problem!

 

Alan
 

[GM Canada]

Magzy, email Tom again and explain what you have done, and ask if he can get a replacement controller sent direct to you from a local dealer to save time.

Alan

No need for that, Magzy is one of my customers. Since I am now convinced that at least the controller has failed I'll be sending one out today! I have no spare bearings, but as you suggested it might be a good idea to try the controller first.

Gary

[Magzy]

http://australia.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=4090417

Can anyone confirm these are the correct bearings for the MP??

[Bikemad]

Magzy, the bearings you've found seem to be a different size to this one:

I checked my MP today and this is the result:

MP part number is MP-1-270-10050059.

The bearing is a 6302RS; 42mm diameter, 15mm hole, 13mm width. Available from McMaster-Carr in the US. I ordered a pair today, will report on the results. At least on the end I looked at, the bearing is secured by a circlip and is not a press fit so can be removed very simply. Whether this is true on the other end, I don't know yet since I haven't removed the other cover.

Michael

Hope this helps.

Alan