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

[Cornelius]

Magzy; check your bearings before ordering new ones, both type and if you really need new ones.

I'm against wasting money before the reason for the problem are located...

[Magzy]

Update with Pics.

I opened the motor just now and here's my findings. 


My workshop



My workbench



Freewheel side Bearing is OK.



Spinning the freewheel side bearing on my finger with ease. No drag.



Cable side bearing is slightly more difficult to turn - in comparison to the freewheel bearing side.
It is also very slightly loose, allowing the whole rotor to move slightly.



Inspect for any damage/ rubbing on the magnets. Hmmm...


A closer look... lots of scratches on the magnets where the lose bearing has allowed the rotor to rub against the stator.



A look on the other side...



no damage here on this side.



 

I can't see any evidence of the wires rubbing against the housing or any burned out wires of any sort...

Now if I was to get a new bearing set myself from RS, I'd have to put the same make/model on either side because this just makes sound engineering sense - they will also be more reliable.

The good bearing on the freewheel side would have to come out but it's stuck solid fast, there's no way it's coming out without a lot of force.

Also, to get that damaged bearing off the motor i'd have to un-wire all the connectors going to the damaged controller, replace the bearing, then re wire the connections which while is not beyond my abilities, is a massive pain in the arse.

There's also the possibility that the rubbing of the motor against the magnets has caused other issues that have yet to be seen.

The fact that this motor is brand new with less than 1KM on the clock and the motor is unfit for use and the controller has blown is a massive let down.

 

However, I have compete faith in Gary from GM Canada and Tom from GM and that they won't leave me out in the cold and will expedite my situation by any means necessary.

 

[Cornelius]

Now, how about that.

Swapping both bearings would, as you say, make good sense. Even if that good bearing are barely used. Getting that freewheel side bearing out should be easy by using a tube that fits the inner ring of the bearing, knocking it out from the freewheel side. (No worry about damaging the bearing, since you wont be using it. Try knocking it out evenly though, so the bearing seat in the housing are not damaged. )

I would suggest assembling the new bearings on the axle on both sides, using again a tube that fits exactly over the inner ring of the bearing/outside the axle. When inserting bearings, never hit the outer ring of the bearing when fitting it on an axle, and never hit the inner ring when fitting it in the housing.

Now, why did the controller failed?!
It could just have been a weak component failing due to excessive load when the stator rubbed against the rotor, and it could also be some of the coil wires getting its protective varnish rubbed off, and getting shorted against the rotor.
The latter shouldn't be a problem with new bearings, but i'd inspect the coils closer, just to be sure; look for a lighter copper color...

Btw:
Which type bearing is it? 6202 or 6302? I can't quite make it out from the pictures...

[Leslie]

It is also very slightly loose, allowing the whole rotor to move slightly.

Got to love that.  Ha.

Great work there man.

Yes I thought if the wheel felt solid then it may of been electro mechanical. Hubs can make all sorts of strange noises.

[Magzy]

Assuming Tom turns around and sends me a new motor, what's the lead time on getting replacements?

Is it still 10 days or do they send them by sea mail. (I don't want to wait 3 months for a boat to arrive)

Also, will it be just the motor or the motor and the rim - (i don't fancy having to respoke a whole wheel)

I've yet to get a response from Tom regarding the above and kind of feel a bit left out in the cold to be honest.

 I know they will sort it in the end but it's the "not knowing how long" and not getting a response from Tom about how long it's going to take which is such a massive disappointment.

Summer is here in Australia! 24C today and perfectly sunny but I'm stuck on the sweaty bus when I should be on my bike.

Magzy

[Leslie]

There is a good chance the hall sensors failed due to the abrasion and vibrations, I think maybe you should get some more parts sent from Gary.  Im sure he will put some more focus on your problems here.

I suspect a controller would come by air mail.

May be wise to replace the hall sensors before the controller.  Its not too hard as the hardest part is taking the wheel apart and to fix its doing all the right thing in the right order of operation.


We can sort this mess out, please have faith.

[Magzy]

There is a good chance the hall sensors failed due to the abrasion and vibrations, I think maybe you should get some more parts sent from Gary.  Im sure he will put some more focus on your problems here.

I suspect a controller would come by air mail.

May be wise to replace the hall sensors before the controller.  Its not too hard as the hardest part is taking the wheel apart and to fix its doing all the right thing in the right order of operation.


We can sort this mess out, please have faith.

Hmm, what *exactly* is a hall sensor? is there a simpletons explanation as to what it does and looks like?

Magzy

[Leslie]

Hall sensors are what detect the motor position.  They are 3 electronic chips glued into the stator formers that monitor the magnetic poles and thus talk to the controller and the controller phase wires oprate the motor in good timing,





http://visforvoltage.org/forum/control-systems/1693

http://www.honeywell-sensor.com.cn/prodinfo/magnetic_position/installation/p88781_2.pdf

The SS41 HoneyWell is a good part number.

I am not entirely sure if 5 beeps superseeds3 beeps and on one of my Pie it doesnt beep at all.

The controller can work in sensorless mode but its less smoothn in operation, and those hall sensors can be difficult in some parts to get easily, if you get my drift.

All my MP functions work ATM touch wood except for one motor wont beep when I unplug say the throttle connector.

But here is a question I'd like to know the answer too.

Say if a controller hall sensor failed and a FET would the controller give 3 beeps then five, what happens when there are multiple errors?

[Magzy]

Thanks for the info but If I was an electronics engineer then I'm sure this would be easy.

But it looks far too advanced for me. Sorry but thanks anyway.

Also, I really don't have the time or inclination to put right errors made by the manufacturer. Even taking the wheel apart took the best part of a day and replacing hall sensors looks way way over my head.
I coult take it to an electrical engineer with all the correct equipment but this would cost upwards of a couple of hundred bucks.

As far as I'm concerned, I have paid a fair chunk of cash on a box of bits consisting of a broken controller and a dismantled Magic Pie a broken bearing which caused broken Hall sensors and top top this off, silence from Golden Motor staff on *exactly* what they're going to do about it.

Granted, I have a new controller on the way but It might be coming on the back of a camel for all I know. and any reasonable attempt to contact Gary from GM Canada or Tom from GM china have been met with silence over the past 7 days. I would have expected at least - 'yes were working on it bear with us' but to be IGNORED is not only unacceptable, but insulting.

Do they not realise that they are committing fiscal suicide by treating customers (not just me but others) like this?

Thanks,
Magzy

[GM Canada]

Granted, I have a new controller on the way but It might be coming on the back of a camel for all I know. and any reasonable attempt to contact Gary from GM Canada or Tom from GM china have been met with silence over the past 7 days. I would have expected at least - 'yes were working on it bear with us' but to be IGNORED is not only unacceptable, but insulting.

Hi Magzy

The controller was sent air mail on Oct 21st. 6-10 business day service. Ill send you an email with the tracking number. It wont help as all you see is the day is was shipped. This method of shipping does not have updated tracking as a feature. I posted here on the 21st when I shipped it as well as responded to your email on the 23rd. So im not sure where the "no word in 7 days " comes from. Maybe from Tom but not from me. I also am not getting a response from Tom now on resolving your issue. But rest assured I am working on it.

Gary

[MonkeyMagic]

Good on you Gary, doing this without feet and all. Highly impressed

[Magzy]

Gary - Thanks for sending the controller - it arrived yesterday and I fitted it on the reassembled the motor to test it out an it fixed the no-go issue.
I bent a couple of the clips and lost another in the bushes as it flew off so I'm not so sure if it's safe anymore - the whole thing wobbles moves across the axle leading to the question of if it's safe to ride or not (?)

The loud electrical Pinging/knocking noise is still there as it was before and the torque is just not that impressive either. (I could in all honestly accelerate quicker than this MP)

I don't think the bearing is the source of the noise because it’s more of an *electrical* pinging noise and Bikemad suggests it could be failed hall sensors but to replace these myself would be way over my head.

I'm now at a dead end with this motor.

[Magzy]

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

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
 

Hi Alan, I'm beginning to think that the bearing is a non-issue too. I mean it spins, but not freely  when you give it a whiz BUT it doesn't make any noise!

The new controller only fixed the broken controller and the motor now behaves exactly as it did before the first controller failed. (loud knocking/ pinging noise when under load)

I'm very reluctant to use the motor now because it may fry the controller again.

I had a look at the Hall sensors and they have not been damaged by the lose bearing because they're all slightly inset into the stator and the white sealant is still intact.

This leading me to believe that they could have indeed been fitted the wrong way or something because the noise is too uniform across the speed spectrum of the motor. It only happens when electricity is going into the wheel and it's under any load or acceleration.

for example. Picture this. If I stand beside the bike and put the throttle on so it does a small wheelie but I hold on to the handlebars and introduce a little load into the wheel, I get the pinging noise. I can slow this process right down where there is very minimal throttle and very minimal movement and get a distinct electrical clicking/pinging noise who's frequency is inversely proportional to the distance the wheel is turned.

Doing the same with just the pedals and no throttle will not produce any electrical/ pinging noise.

It's an *electrical* noise not a *mechanical* or  bearing one (although the bearing is shagged)

GM are refusing point blank to do replace it.

It's 2 months today since I ordered this motor and haven't used it yet. Maybe I should resign myself to having been ripped off by Golden Motor to the tune of a few hundred dollars. At least I'll be able to have some closure on the whole disappointing episode.

Magz

[Leslie]

Magzy there seems to be too much wrong with your wheel, I think you deserve a full replacement to be honest.

If it was just a controller or hall sensors Id say fix it.  But there are three major problems with your kit.

First mechanical.  Second electrical, and third, the first and second are making more problems.

[Leslie]

You could try different colour combination's of your phase wires.  Dont be to harsh on the throttle when testing it.  Either it will work, or not work well, or not work at all..

Try the phase wires first.

BYG BGY GBY GYB YBG YGB

Then try the hall sensors but in different combination to the above.  Muzza posted a spreadsheet here of all the possible combination's.  Dont change the red or black wires.