King Song S22 motor stator slippage issue: more severe than expected

[mike E]

just spoke to my local dealer here in Australia re the ks22 motor issues, and was told the following:

1. there is NO official recall in china or anywhere else regarding the motors

2. there are certain ppl in the community making much noise ( unsubstantiated ) about these issues 

3. of the 35 units they have sold here there has been NO issues apart from one with a loose bearing which they fixed with a hammer

4. the 2 original test units they have are still performing well with NO issues

5. they are in constant contact with Kingsong re any issues with the KS22 and have nothing official to report as of now (although he says kingsong will be advising them about some testing procedure some time in the future)

6. they are unaware of this thread and its content

my ks22 is performing ok as of now BUT I am hesitant to ride it after reading about all the issues

I am confused 

[Rawnei]

4 hours ago, mike E said:

just spoke to my local dealer here in Australia re the ks22 motor issues, and was told the following:

1. there is NO official recall in china or anywhere else regarding the motors

2. there are certain ppl in the community making much noise ( unsubstantiated ) about these issues 

3. of the 35 units they have sold here there has been NO issues apart from one with a loose bearing which they fixed with a hammer

4. the 2 original test units they have are still performing well with NO issues

5. they are in constant contact with Kingsong re any issues with the KS22 and have nothing official to report as of now (although he says kingsong will be advising them about some testing procedure some time in the future)

6. they are unaware of this thread and its content

my ks22 is performing ok as of now BUT I am hesitant to ride it after reading about all the issues

I am confused 

Meanwhile every other reseller is aware of the issues and have customers with motor issues, sounds like your reseller is either completely oblivious to these issues which would be strange or just trying to downplay it.

I do wish KS would say something official sooner rather than later instead of working through resellers and keeping customers in the dark.

[oolong]

14 hours ago, mike E said:

just spoke to my local dealer here in Australia re the ks22 motor issues, and was told the following:

1. there is NO official recall in china or anywhere else regarding the motors

2. there are certain ppl in the community making much noise ( unsubstantiated ) about these issues 

3. of the 35 units they have sold here there has been NO issues apart from one with a loose bearing which they fixed with a hammer

4. the 2 original test units they have are still performing well with NO issues

5. they are in constant contact with Kingsong re any issues with the KS22 and have nothing official to report as of now (although he says kingsong will be advising them about some testing procedure some time in the future)

6. they are unaware of this thread and its content

my ks22 is performing ok as of now BUT I am hesitant to ride it after reading about all the issues

I am confused 

The fact that there are very few, if any, high speed cut offs (without warning) related to the issue makes me feel better.  Along with the tests and updates from @supercurio makes me feel that I can take it easy on the wheel, not torque it too much, listen for noises, and generally be okay.  

Unfortunately being informed is a double edge sword.  You're aware of the issues and can mitigate them, but emotionally it makes you a wreck.  Meanwhile there are plenty of people blissfully unaware of the issues and are probably having the time of their lives on their new S22...

[gon2fast]

15 hours ago, mike E said:

just spoke to my local dealer here in Australia re the ks22 motor issues, and was told the following:

KS tried to sell that same BS to eWheels, but KS eventually caved and is sending hundreds of replacement motors now. Tell your reseller to keep pounding on them.

[Forwardnbak]

Your dealer bought 35?  pretty sure your dealer is invested deep in making sure this wheel IS FINE. 
 

 

[supercurio]

Calling @RagingGrandpa for help.

Do you know about a current probe which could be used to record phase current, up to 220A and possibly beyond?

There currently are contradicting opinions regarding the cause of the "clunk" sound that occurs consistently during S22 spin tests. As a result, what this sound means, the validity of any of the stress tests and reliability of the newly produced motors are also in question.

One of the methods to understand the cause of these sounds would be to measure the phase current sent by the board, in order to identify unexpected peaks due to insufficient limits control.

I'm thinking possibly something like 500A+ from the full battery voltage sent into the windings momentarily at the moment the motor is stalled? With a loud sound as a result.

Any suggestion of equipment and methodology welcome!

[NErider]

Keep in mind. Any and all testing is a good thing. But the root cause of the S22 Batch 1 has been pretty well identified as the rotor ring not being glued to the hub by the motor manufacturer during a estimated known time. 

The motor is either glued a d assembled properly,  or must be replaced. 

[supercurio]

9 minutes ago, NErider said:

Keep in mind. Any and all testing is a good thing. But the root cause of the S22 Batch 1 has been pretty well identified as the rotor ring not being glued to the hub by the motor manufacturer during a estimated known time. 

Some observations on that:

There presence of the stator slippage is not a "Batch 1" specifics. Batches are very very loosely defined also.

The main cutoff date would be July (or last days of June) for the motor production date, where the supplier is expected to have addressed the root cause

It has not been investigated specifically yet, but those who opened the motor and also worked on modifications didn't observe glue there (or lack thereof), indicating that the stator would be held by friction.

@NErider the disagreement on what the "clunk" sound is means that the new "fixed" motor, still producing could still have defects, hence the high interest in investigating this fully before hundreds of motors get replaced.

If it's the controller: The firmware must be improved, but there's no hardware flaw.

If it's indeed the sound of the stator being loose, then there's a problem.

[mike E]

6 hours ago, Forwardnbak said:

Your dealer bought 35?  pretty sure your dealer is invested deep in making sure this wheel IS FINE. 
 

 

it is the very same dealer yours came from!! and that is what I was told

[Tawpie]

4 hours ago, supercurio said:

Do you know about a current probe which could be used to record phase current, up to 220A and possibly beyond?

Not "record", but measure: https://a.co/d/7jRJZwO

High current probes are large beasties, not "really" suitable for use while riding. If you want to record you'll need one that can interface with a data logger, and then you'll need a data logger that'll interface with your current probe.

[Eucner]

8 hours ago, supercurio said:

I'm thinking possibly something like 500A+ from the full battery voltage sent into the windings momentarily at the moment the motor is stalled?

Any suggestion of equipment and methodology welcome!

For safety and convenience I would use AC/DC current clamp and portable oscilloscope. The clamp mounting might also require a short phase wire extension cord.

[techyiam]

6 hours ago, mike E said:

it is the very same dealer yours came from!! and that is what I was told

Wait a minute, @Forwardnbak S22 had motor failure.

[supercurio]

@Tawpie @Eucner yes it would about recording for later visualisation and analysis.

The use case would be to record the phase current and identify any spike in current when completing a spin test and reproducing the "clunk" sound.
In order to confirm if it's due to a current limiting problem by the mainboard firmware, when the motor is briefly in the stall position (and nothing mechanically wrong with the motor)

 

[Forwardnbak]

1 hour ago, techyiam said:

Wait a minute, @Forwardnbak S22 had motor failure.

well, i’m not sure. I just went off what KS told me when I sent them videos. 

I also know of another that had another issue locally. 

The dealer has a good rep so i’m sure you’ll be well covered incase any service is needed. 

 

 

[mike E]

24 minutes ago, Forwardnbak said:

well, i’m not sure. I just went off what KS told me when I sent them videos. 

I also know of another that had another issue locally. 

The dealer has a good rep so i’m sure you’ll be well covered incase any service is needed. 

 

 

Can you elaborate on the other issue that you know of?

 

[supercurio]

On 9/14/2022 at 5:56 AM, mike E said:

just spoke to my local dealer here in Australia re the ks22 motor issues, and was told the following:

1. there is NO official recall in china or anywhere else regarding the motors

Thanks for sharing!
I can confirm that's what most dealers have been told, indeed. I think it will remain an "agree to disagree" kind of thing.

On 9/14/2022 at 5:56 AM, mike E said:

2. there are certain ppl in the community making much noise ( unsubstantiated ) about these issues 

Probably was a KS rep in full denial mode speaking here, before KS formed this team to enhance collaboration.

On 9/14/2022 at 5:56 AM, mike E said:

3. of the 35 units they have sold here there has been NO issues apart from one with a loose bearing which they fixed with a hammer

Entirely possible yes, the failure rate on the stator slippage seem to vary quite a depending on factors like motor production date.
From 100% to 0% on whichever sample size and delivery is concerned.

I'm glad that it's not 100% on everything, but it makes it very difficult to predict.

On 9/14/2022 at 5:56 AM, mike E said:

4. the 2 original test units they have are still performing well with NO issues

5. they are in constant contact with Kingsong re any issues with the KS22 and have nothing official to report as of now (although he says kingsong will be advising them about some testing procedure some time in the future)

6. they are unaware of this thread and its content

Let's make then aware then! I'll also be happy to invite them to the group of dealers I've created, where most of the dealers you've heard about already share information on the matter. I'll send you a private message to see if we can make this happen so they get the best info and you get the best service.

On 9/14/2022 at 5:56 AM, mike E said:

my ks22 is performing ok as of now BUT I am hesitant to ride it after reading about all the issues

Understandable.
I would recommend to run the tough (max rpm) spin test described earlier and share a video of it here. While the test is demanding to execute fully, it is the best way to identify bad motors known so far (including by King Song QA)

[Forwardnbak]

22 minutes ago, mike E said:

Can you elaborate on the other issue that you know of?

 

it was not related to the motor and seemed to be control board related. The other user messaged me and is a part of the community. 

[BIGboiFASTboi]

I've been hearing about the board problems as well, from credible sources, and seen first hand at the Amped Electric Games. 

I haven't read through all 7 pages of commentary on this thread -- but one of my standard procedures when I buy and "break in" a new wheel is a pendulum test.  I stand up against a wall, or next to a pole and torque back and forth 100-200 times.  It's actually an overheat test, but I feel like this would be an interesting test for S22 owners to perform.  It would torque the motor, as well as put load on the controller, which seems to have issues with low speed, high torque events, in my opinion.

Anyone daring enough to try it?

[Eucner]

35 minutes ago, supercurio said:

The use case would be to record the phase current and identify any spike in current when completing a spin test and reproducing the "clunk" sound.

To catch short current spikes you need an oscilloscope. Logging multimeters have too long (>1 s) measurement intervals.

The current clamp needs to have enough bandwidth (>1000Hz). I would also look for DC current. There shouldn't be any, but still I would check it.

When started, it would be nice to know the insulation resistance.

I'm having Fluke 196C ScopeMeter insulated 2 channel oscilloscope, Fluke i1010 AC/DC current clamp and Megger MIT420 insulation resistance tester. They would be pretty ideal for your testing.

[tk463]

16 hours ago, Forwardnbak said:

Your dealer bought 35?  pretty sure your dealer is invested deep in making sure this wheel IS FINE. 
 

 

That doesn’t mean anything. My dealer bought 30 and is still crapping on their customers.

[supercurio]

I'm trying to confirm a theory:

A quiz for all of you: despite the difference in acoustics and execution speed, which "clunk" sound do you find to be the same or different?

 

[djkillermemestar]

Made an account to chip in on this.

 

I had a motherboard issue around a week after having my wheel.

 

Just replaced it not to long ago. But now i see all these things.

 

I've not heard any scraping or wierd noises from my wheel yet, so not sure if i have motor issues. I've read all 7 pages of this forum but am still a bit worried about doing the test.

 

I'm not the most strong guy in the world so i might go to my dad and ask if he can help 😀.

 

My dealer (MyEwheels, europe) did say my motor should be fine, so not dure what to do

[Tawpie]

1 hour ago, supercurio said:

which "clunk" sound do you find to be the same or different?

motor4 sounds different, it stutters into the stop without clunking. motors 1-3 clunks sound the same.

[Jamroxorz]

4 hours ago, supercurio said:

I'm trying to confirm a theory:

A quiz for all of you: despite the difference in acoustics and execution speed, which "clunk" sound do you find to be the same or different

1-3 sound similar. 4 sounds like it stops with a crunching like sound.

[Luke44C]

1 and 2 definitely sound the same, 4 is noticeably different as the others have mentioned. 3 is close to 1 and 2, but sounds a touch different to me; hard to tell if it's a different root cause, or just a difference in recording equipment or environment