KS-18XL new with bad motor, rim & tyre sideways wobble

[Smoother]

I would raise the snap crackle pop as an issue too.  I'm going to listen to my wheel and see if it's full of breakfast cereal too.

( a few minutes later)

Just had a good listen, no breakfast cereal sounds, not even oat meal.  I can't think what would make that noise.  there's only one moving part; the wheel which has five sources of possible extra noise; either of the two bearings, or contact between the wheel and the magnets/ armature, or foreign material inside, or contact of the tire with the shell or something trapped inside the shell (twig, or mud, I've had both, or some other foreign matter).  One rider last year got a King Song with an extraneous washer floating around in the motor, so it does happen.  IF you have foreign matter, it would be very small, that's IF.

1 hour ago, bruno356 said:

Is the rim where the magnets are located also wobbling from side to side.

Yes, glued to the inside of the rim assembly.

[Marty Backe]

5 hours ago, Gfr said:

Hello,
No, 500 kms traveled like this.

That's the answer that I was expecting.

[Micheal Shen]

Your video is very interesting, and i search this in internet where it is called END PLAY. END PLAY is inevitable in brushless wheel hub DC motors' movement. which cause snap crackle pop. The bigger the axis END PLAY amount is, the louder the noise is, as well as wheel temperature and power consumption.

Just now, i get a positive answer from one of the biggest wheel hub motor suppliers in China, who give their test standard range as below

14inch wheel hub motor: 0.2~0.6mm / max side-play amount

16inch wheel hub motor: 0.4~0.8mm / max side-play amount

18inch wheel hub motor: 0.6~1mm / max side-play amount

Since i am not engineer, or acquiring knowledge of motor dynamics, so this standard can be the reference.

[mrelwood]

Watching the original video again, it looks to me like (in addition to the rim wobble) the black motor cover is separated from the rim at one point. If you didn’t yet send the wheel back, I would inspect it closely. I guess it might even be possible that one of the motor cover screws was loose. Or something in between the rim and the motor cover that prevents the motor cover from sitting flush.

This might not affect the decision wether to send the wheel back or not, but it might be a good argument to back you up. Especially if there is an actual gap that would let dust, dirt and water inside the motor.

[Smoother]

6 hours ago, Micheal Shen said:

Your video is very interesting, and i search this in internet where it is called END PLAY. END PLAY is inevitable in brushless wheel hub DC motors' movement. which cause snap crackle pop. The bigger the axis END PLAY amount is, the louder the noise is, as well as wheel temperature and power consumption.

Just now, i get a positive answer from one of the biggest wheel hub motor suppliers in China, who give their test standard range as below

14inch wheel hub motor: 0.2~0.6mm / max side-play amount

16inch wheel hub motor: 0.4~0.8mm / max side-play amount

18inch wheel hub motor: 0.6~1mm / max side-play amount

Since i am not engineer, or acquiring knowledge of motor dynamics, so this standard can be the reference.

Welcome @Micheal Shen .  Thanks for that info.  Just out of curiosity do you know who this motor supplier supplies motors to?

[bruno356]

On 4/9/2019 at 1:17 PM, Micheal Shen said:

Your video is very interesting, and i search this in internet where it is called END PLAY. END PLAY is inevitable in brushless wheel hub DC motors' movement. which cause snap crackle pop. The bigger the axis END PLAY amount is, the louder the noise is, as well as wheel temperature and power consumption.

Just now, i get a positive answer from one of the biggest wheel hub motor suppliers in China, who give their test standard range as below

14inch wheel hub motor: 0.2~0.6mm / max side-play amount

16inch wheel hub motor: 0.4~0.8mm / max side-play amount

18inch wheel hub motor: 0.6~1mm / max side-play amount

Since i am not engineer, or acquiring knowledge of motor dynamics, so this standard can be the reference.

Hi, Not sure what the term "End Play" means as you interpret it, but my understanding of end play is when one has movement end to end along the axis of a shaft, example, a small electric motor shaft usually has end play to allow for for expansion/contraction due to temperature change, to stop the shaft moving a Spring Wave Washer is placed at one end.

This 18XL motor rim assembly is buckled that is why it is moving side to side as its rotating, not because of end play.  Obviously the magnets are also moving slightly from side to side across the width of the stator. (Not lining up perfectly as they should and causing inefficiencies).

To be honest to have so much wobble on assembled machined components just shows the lack of skill (or I do not care attitude) applied in manufacturing (very shoddy workmanship).

According to the supplied tolerances my 18 inch wheel is at at the maximum 1mm tolerance end.

Thanks for the reply and the reference chart.          Regards - Bruno

Edited April 13, 2019 by bruno356

[bruno356]

On 4/9/2019 at 4:11 PM, mrelwood said:

Watching the original video again, it looks to me like (in addition to the rim wobble) the black motor cover is separated from the rim at one point. If you didn’t yet send the wheel back, I would inspect it closely. I guess it might even be possible that one of the motor cover screws was loose. Or something in between the rim and the motor cover that prevents the motor cover from sitting flush.

This might not affect the decision wether to send the wheel back or not, but it might be a good argument to back you up. Especially if there is an actual gap that would let dust, dirt and water inside the motor.

Hi @mrelwood  thanks for drawing this to my attention, I did not originally look that closely and thought it was just a bump or bulge in the casting. In fact one screw was not seated all the way down (it was against the motor cover flange but not fully down to the rim face) and the thread of the screw had locked up in the motor cover flange hole. After tightening it down properly the two screws, one either side, were also loose, tightened those and then checked all the other screws just to make sure. Never take anything for granted that from the factory as new, all should be ok, sometimes its not.

But this has not altered or made any difference to the buckled / wobbling wheel.

regards - Bruno

[Smoother]

I'm not sure why you haven't returned this for a refund or exchange. Is your dealer from outside the country (making it cost prohibitive)?

Here's another idea, sell it on to someone who will accept the wobble for a little discount, and try/buy again.  Australia's a big place so I'm not sure if you're in a big metropolis or the outback.  That would determine the feasibility of this strategy.

Strategy three, get a new motor assembly.  They aren't that expensive (but not cheap either) yes you'll be out even more money and there is no guarantee the new motor wont be as bad or worse than the original.

Just trying to get your creative juices flowing.  I have been sitting on a repair issue (not EUC related) for weeks due to a stumbling block, then suddenly yesterday I realized I had an entirely different solution  from the one I had planned but could not execute, just waiting for me to try.  It worked.  One hour later my midi input device was fixed.

Sometimes one has to step away from the problem and shine a different light on it, to discover a different solution.

Edited April 13, 2019 by Smoother

[Guest PogArt Artur]

On 4/2/2019 at 3:27 AM, bruno356 said:

Hi @US69 and others, First post so hope I am doing things right.

Just recently receives my new 18XL and was disappointed that the wheel assembly (motor and rim) was so badly running out of true (buckled). The rim moves side to side by 1mm, KingSongs recommendation was to hit it with a rubber mallet to straighten it. (Very sorry, I ask engineer again, may need to buy a rubber hammer to adjust the motor. No need to disassemble the motor, hammer on the motor bulged side directly.)

Not the reply I expected as you can imagine, I looked deeper inside the body of the 18XL and found the whole motor and rim assembly wobbled, no way a rubber mallet would fix this.

When running the wheel on a stand of course the whole thing vibrates due to the bad motor rim assy.

After contacting KingSong again the second reply was (The wobble is normal, We have also asked big motor supplier checked the video, the conclusion is 18L motor is big, the small wobble shown on your videos is within allowable range.) 

Having read all the praises here regarding KingSong Quality I am naturally very disappointed.

Please look at the video and let me know if this is normal for KingSong wheels.

To me it's obvious - it is wrong!

Just logically - there's no such wobbles on bicycles, motorcycles, cars .., etc.

Because it is wrong.

Fixing wobbles by rubber hammer?

It's not fitting the wooden panels on the floor, is it...?

I couldn't believe what Customer Support advised you, and why they kept ensuring you that everything is acceptable regarding your issue...

Unbelievable   

[bruno356]

On 4/13/2019 at 8:37 PM, Smoother said:

I'm not sure why you haven't returned this for a refund or exchange. Is your dealer from outside the country (making it cost prohibitive)?

Here's another idea, sell it on to someone who will accept the wobble for a little discount, and try/buy again.  Australia's a big place so I'm not sure if you're in a big metropolis or the outback.  That would determine the feasibility of this strategy.

Strategy three, get a new motor assembly.  They aren't that expensive (but not cheap either) yes you'll be out even more money and there is no guarantee the new motor wont be as bad or worse than the original.

Just trying to get your creative juices flowing.  I have been sitting on a repair issue (not EUC related) for weeks due to a stumbling block, then suddenly yesterday I realized I had an entirely different solution  from the one I had planned but could not execute, just waiting for me to try.  It worked.  One hour later my midi input device was fixed.

Sometimes one has to step away from the problem and shine a different light on it, to discover a different solution.

@Smoother the market here is still very small, the company I purchased from is in Australia, return shipping is not prohibitive and I am in the metropolitan area. At the moment no one has stock of the 18XL (18L is available). Recently an exclusive dealer for Australia  was appointed by KingSong, he has nil stock at the moment but a considerable retail price increase has been applied to the wheels.  The supplier of my wheel now has to purchase from the appointed dealer.

As you say what guarantee do I have the replacement motor assembly is going to be any better? KingSong in their reply email have already stated that for its size the wheel I have is within acceptable limits (I find myself between a rock and a hard place).

The feedback from this forum seems to indicate that a certain amount of wobble is quite common, @kasenutty just recently received his new 18XL, it will be interesting to see how his wheel /rim is.

regards - Bruno

[Smoother]

11 hours ago, bruno356 said:

@Smoother the market here is still very small, the company I purchased from is in Australia, return shipping is not prohibitive and I am in the metropolitan area. At the moment no one has stock of the 18XL (18L is available). Recently an exclusive dealer for Australia  was appointed by KingSong, he has nil stock at the moment but a considerable retail price increase has been applied to the wheels.  The supplier of my wheel now has to purchase from the appointed dealer.

As you say what guarantee do I have the replacement motor assembly is going to be any better? KingSong in their reply email have already stated that for its size the wheel I have is within acceptable limits (I find myself between a rock and a hard place).

The feedback from this forum seems to indicate that a certain amount of wobble is quite common, @kasenutty just recently received his new 18XL, it will be interesting to see how his wheel /rim is.

regards - Bruno

Well you still have the Jeremy Clarkson option... (hit it with a big hammer)

[kasenutty]

I haven't checked mine, and I probably won't unless I have a reason. I've put about 150 miles on mine and it rides great so I really have no reason to gather evidence. I asked @bruno356 how his wheel rides and never got an answer back. My wheel rides like the best wheel that was ever built, so I am very happy with it and not really caring what the footage from underneath looks like at the moment  

[Smoother]

3 hours ago, kasenutty said:

I asked @bruno356 how his wheel rides and never got an answer back.

Last time I heard ee hadn't ridden it, to allow for 100% refund/exchange,etc  But that possibility seems doubtful now.

[Guest PogArt Artur]

6 hours ago, kasenutty said:

I haven't checked mine, and I probably won't unless I have a reason. I've put about 150 miles on mine and it rides great so I really have no reason to gather evidence. I asked @bruno356 how his wheel rides and never got an answer back. My wheel rides like the best wheel that was ever built, so I am very happy with it and not really caring what the footage from underneath looks like at the moment  

I'm gkad you enjoying your new wheel @kasenutty !!!

It must be awesome feeling riding on upgraded wheel

Enjoy !

[bruno356]

7 hours ago, kasenutty said:

I haven't checked mine, and I probably won't unless I have a reason. I've put about 150 miles on mine and it rides great so I really have no reason to gather evidence. I asked @bruno356 how his wheel rides and never got an answer back. My wheel rides like the best wheel that was ever built, so I am very happy with it and not really caring what the footage from underneath looks like at the moment  

Hi @kasenutty I did reply to your message on Sunday 14th April perhaps I stuffed up and you did not receive it, below is a copy:-

Hi @kasenutty I have been concerned about it and as it is brand new I did not want to ride it just in case it needed to be returned for a full refund and unused. Have received various feedback, some say they do not have the side to side wobble problem on their wheels (they are running true) and some do have the wobbling wheel but apparently it does not affect the ride.

Placing the 18XL on a stand I can feel the out of balance / misalignment of the wheel, the faster it spins the worse the vibrations (but this may not affect the ride?).

As yours is probably about the same generation as mine I thought it would be a good way to make a comparison.

Hope you did not mind me asking. Would be great If you could get back to me, I have to make a final decision soon (keep or send back).

Thanks & Regards - Bruno

[kasenutty]

You never told me how it rides, have you tried it yet? I am not the kind of guy who could let a new wheel sit around and not try it at least once  

[Marty Backe]

2 hours ago, kasenutty said:

You never told me how it rides, have you tried it yet? I am not the kind of guy who could let a new wheel sit around and not try it at least once  

This is his first wheel. That's part of the reason for his uncertainty. He has no reference to judge this wheel.

And of course he can't actually ride it even if he wanted to.

[kasenutty]

OH! Well, that makes sense. I was like that with my first wheel too. I always thought it was broken and was always worried about it. I did break it though, so my worries were warranted, although it took a year or so  

[Micheal Shen]

@bruno356 Actually, every electric motor have shaft end play, no one can design a electric motor without end play. Although i am not good at motor shaft theory, but google tell me many useful thing about this. A good motor may have 0.001" for dual side end play, and this motor may cost sky-high price.

Look at the shaft end-play of Mercedes Benz M112 2005, 0.0104 +/- 0.0039, I guess the C300 can reach 0.006", but whether the latest Mercedes Benz motor can reach 0.001", i can't search it in internet. If i use magnifying lens to record such video, i also can make it looks like 1", can i say Mercedes Benz' motor is broken or defect one?

If you check the wobbling measurement is over 1mm, you can ask local distributor to change a motor for you.

[bruno356]

8 hours ago, Micheal Shen said:

@bruno356 Actually, every electric motor have shaft end play, no one can design a electric motor without end play. Although i am not good at motor shaft theory, but google tell me many useful thing about this. A good motor may have 0.001" for dual side end play, and this motor may cost sky-high price.

Look at the shaft end-play of Mercedes Benz M112 2005, 0.0104 +/- 0.0039, I guess the C300 can reach 0.006", but whether the latest Mercedes Benz motor can reach 0.001", i can't search it in internet. If i use magnifying lens to record such video, i also can make it looks like 1", can i say Mercedes Benz' motor is broken or defect one?

If you check the wobbling measurement is over 1mm, you can ask local distributor to change a motor for you.

 

  Hi, this is exactly what my reply stated above about end play in shafts of electric motors, my original query to the forum was about the wobble by 1 mm of my wheel due to a warped motor/rim assy, there is no end play in my motor shaft (certainly not of any significance that I can measure).

Your original table was very informative - thanks for that

14inch wheel hub motor: 0.2~0.6mm / max side-play amount

16inch wheel hub motor: 0.4~0.8mm / max side-play amount

18inch wheel hub motor: 0.6~1mm / max side-play amount

regards - bruno

[Micheal Shen]

12 hours ago, bruno356 said:

  Hi, this is exactly what my reply stated above about end play in shafts of electric motors, my original query to the forum was about the wobble by 1 mm of my wheel due to a warped motor/rim assy, there is no end play in my motor shaft (certainly not of any significance that I can measure).

Your original table was very informative - thanks for that

14inch wheel hub motor: 0.2~0.6mm / max side-play amount

16inch wheel hub motor: 0.4~0.8mm / max side-play amount

18inch wheel hub motor: 0.6~1mm / max side-play amount

regards - bruno

Ha ha, the thing is simple, and shaft end play is normal phenomenon in all electric motors.

If this motor is a warped motor, it's very hard for people to stand upon it, let alone riding it. You can take the wheel to the EUC shop and ask their staff to ride it. If they feel very hard to ride it, they will replace the motor for you without any reasons.

Thinking too much will not solve your problems, just do it!

Although I am a Chinese, but China can't make same good motor as German nowadays. Maybe 5 years later, the shaft end play of China motor can reach 0.0039inch, and not easy to be seen by eyes.