My KS-16S lose balance an I fall

[Augus]

I have a problem with the wheel. It lose the balance from time to time especially when braking, but It also happen when accelerate. It is not a cut-off, the wheel is not turned off, the balance is lost and tilt backwards or forwards and I fall.  After that it returns to take the balance and works smoothly until it happens again. 
Since the motherboard is quite new, because I bought it less than 1 year ago, I think the problem is the motor or motor sensor. 
What do you think?

[TomOnWheels]

First of all, do calibration... then if it still losing balance you are good to take it to service centre...  Probably motherboard or hall sensor...

[Chriull]

4 hours ago, Augus said:

I have a problem with the wheel. It lose the balance from time to time especially when braking, but It also happen when accelerate. It is not a cut-off, the wheel is not turned off, the balance is lost and tilt backwards or forwards and I fall.  After that it returns to take the balance and works smoothly until it happens again. 
Since the motherboard is quite new, because I bought it less than 1 year ago, I think the problem is the motor or motor sensor. 
What do you think?

No idea by now. But if you can log one of this events while accelerating with wheellog i can (most) probably tell you if this wheel is too weak for your driving style and it was "just" an overlean or its some other problem.

Just as very very very wild speculation - your battery is in perfect shape? Charging up to ~67.2V? What voltage reports the app after a real full charge?

[Augus]

It seems to have been fixed my problem with the downgrade to firmware v 1.08 

[Augus]

Well, in the route today the problem happened again (with the firm 1.08), so the cause is another. I can not replicate the problem, since next it works well.

The common circumstances of the different times is with battery beloww 50%, braking, at low speed, never normal or high speed (fortunately).
What happens is that the motor suddenly starts making a loud noise, like a ratchet, and loses the balance without shutting down.
This last time has been recorded with the WheelLog, and you see that the current drops to 0 (picture)
The batteries are new (not KS original), mounted by a reputable company, with Samsung INR18650-35E cells.
I changed the motherboard less than 1 year ago.
Does anyone think that it can be?, some loose cable, motor, engine sensor, defective battery?

Edited May 19, 2019 by Augus
error

[Chriull]

14 minutes ago, Augus said:

The common circumstances of the different times is with battery beloww 50%, braking, at low speed, never normal or high speed (fortunately).
What happens is that the motor suddenly starts making a loud noise, like a ratchet, and loses the balance without shutting down.

There are three things that come to my mind:

- "magnetic slip" if one brakes or decelerates too hard, the motor slips one "position", gets caught again, slups, and so on. Can sound like ratchet. But i'd say the motors are too strong as such things could happen?

- somethings mechanicly "a bit" loose inside the motor and rattoes under high burden. One of the permanent magnets not really fixed? 

- some current limiting of the mainboard which kicks in and releases fast enough to make this rattling sound. Was afaik sometimes reported with earlier GWs doing fast accelerations at low speeds? Could maybe also hapoen while braking if there is some regerenerative current limit?

 

Quote

This last time has been recorded with the WheelLog, and you see that the voltage drops to 0 (picture)

Speed and current drops to zero - no voltage shown?!

You have the csv log file?

Quote

The batteries are new (not KS original), mounted by a reputable company, with Samsung INR18650-35E cells.

You know the specs of the BMS used? But as you wrote that the wheel did not shut off, it should be no BMS cut off?

Maybe, if its some weird BMS behaviour it only shuts off very shortly and comes back quite imedeately? So the mainboard could overcome the shutoff times with its capacitors, but this weird situation leads to stopped balancing? .... Is some very wild and weird soeculation....

Quote

I changed the motherboard less than 1 year ago.
Does anyone think that it can be?, some loose cable, motor, engine sensor, defective battery?

Hard to analyze - there are too many unknowns...

I would rule out loose contacts, as your incidents just happen while high burdens (acceleration,braking) and everything works fine otherwise?

The company replacing the battery is experienced with EUC requirements? Normal EBike BMS can be a bad choice for EUCs. You asked them already about your problems. Did the problems start with the new battery? The battery charges to the max voltage(~67.2V)

Log files from these incidents could maybe reveal something?

Did you already make a visual inspection of the internals ?

[Augus]

2 hours ago, Chriull said:

Speed and current drops to zero - no voltage shown?!  -  Yes, current, sorry

You have the csv log file? Yes, I attach the WheelLog csv

The company replacing the battery is experienced with EUC requirements? Normal EBike BMS can be a bad choice for EUCs. You asked them already about your problems. Did the problems start with the new battery? The battery charges to the max voltage(~67.2V)

    The battery is made by 'Chris' https://www.1radwerkstatt.de/. He is a great expert in EUC batteries. I talked him about the problem. I changed the batteries in february 2019, and the problem began a few days ago. I have to check that the batteries charge.

Did you already make a visual inspection of the internals ? I will

 

2019_05_19_12_37_13.csv

Edited May 19, 2019 by Augus

[Chriull]

1 hour ago, Augus said:

 The battery is made by 'Chris' https://www.1radwerkstatt.de/. He is a great expert in EUC batteries. I talked him about the problem. I changed the batteries in february 2019, and the problem began a few days ago. I have to check that the battery charges to the max voltage.

Great - so there should be no connection between your incidents and the batteries - but maybe he is able to find the problem and help you out!

 

3 hours ago, Augus said:

The common circumstances of the different times is with battery beloww 50%, braking, at low speed, never normal or high speed (fortunately).
What happens is that the motor suddenly starts making a loud noise, like a ratchet, and loses the balance without shutting down.

Your picture already looked a bit strange - now with the wheellog data it seems obviously some system fault:

Your logged (from the KS16S reported) speed stays absolutely constant at 25,62 km/h between 13:24:36,55 and 13:24:48,39. All other values (current, temp, voltage, distance,...) were transmitted normally in this time!

Here once again a bit more zoomed:

You were driving at around 16-17 km/h got a bit slower ~15 and then the log shows an acceleration from ~15 km/ to this "fixed" 25,62 km/h within 1,22 seconds. Quite "nice" but realistic acceleration of 2,3 m/s² - did you/the wheel accelerate or is this just shown here? Inbetween the maximum acceleration is about 5m/s².... quite high?!!

After that there is some regenerative braking (negative current, voltage going up) and in the end a big current peak with a voltage sag shown - the end of your "incident". All at "impossible" constant speed reported....

This ("no" speed shown) and the motor rattling (ratched noise) shows the EUC controll out of bounds? Maybe the hall sensor signal missing/disturbed? But strangely only while stronger braking/accelerating? And just sometimes? Maybe really a bad/loose contact? Or just some "weird" defect at the motherboard? Some chip going crazy? Imho nothing to be solved by you/us. With much good fortune you maybe find at your visual inspection some not really fixed connector/"strange" signs at the motherboard/ broken insulations at the cables?

 

At the end of your log there is another strange situation?:

 

There are big speed/current/voltage spikes with about 7 Herz. Much to fast for some willingly acceleration/braking manouver? Is this some "special" trick of you, did the wheel "oscillate" or was this one "ratched noise" event too?

And FYI - you had about(almost) an overlean while your ride:

While you seem to ride normally in a "sane/and safe" region there once this red dots coming near the blue limit line and (?almost?) touching it, before you stopped accelerating and "really" overleaning. This (?almost?) touching the limit line was before tilt-back speed (note - the numbers for speed in the above diagram are not really km/h...)

 Here the "normal" graph of this near limit incident:

Did you already notice something or was it just good luck/gut feeling that you stopped accelerating?

ps.: this "limit values" come from my KS16S, and the values for lift-cut-off speed, "failure" factors for reported current,voltage can differ between our "same" wheels and the distance to the limit with yours a bit farther...

Edited May 19, 2019 by Chriull

[Augus]

2 hours ago, Chriull said:

Great - so there should be no connection between your incidents and the batteries - but maybe he is able to find the problem and help you out!

 

Your picture already looked a bit strange - now with the wheellog data it seems obviously some system fault:

Your logged (from the KS16S reported) speed stays absolutely constant at 25,62 km/h between 13:24:36,55 and 13:24:48,39. All other values (current, temp, voltage, distance,...) were transmitted normally in this time!

Here once again a bit more zoomed:

You were driving at around 16-17 km/h got a bit slower ~15 and then the log shows an acceleration from ~15 km/ to this "fixed" 25,62 km/h within 1,22 seconds. Quite "nice" but realistic acceleration of 2,3 m/s² - did you/the wheel accelerate or is this just shown here? Inbetween the maximum acceleration is about 5m/s².... quite high?!!

After that there is some regenerative braking (negative current, voltage going up) and in the end a big current peak with a voltage sag shown - the end of your "incident". All at "impossible" constant speed reported....

This ("no" speed shown) and the motor rattling (ratched noise) shows the EUC controll out of bounds? Maybe the hall sensor signal missing/disturbed? But strangely only while stronger braking/accelerating? And just sometimes? Maybe really a bad/loose contact? Or just some "weird" defect at the motherboard? Some chip going crazy? Imho nothing to be solved by you/us. With much good fortune you maybe find at your visual inspection some not really fixed connector/"strange" signs at the motherboard/ broken insulations at the cables?

 

At the end of your log there is another strange situation?:

 

There are big speed/current/voltage spikes with about 7 Herz. Much to fast for some willingly acceleration/braking manouver? Is this some "special" trick of you, did the wheel "oscillate" or was this one "ratched noise" event too?

And FYI - you had about(almost) an overlean while your ride:

While you seem to ride normally in a "sane/and safe" region there once this red dots coming near the blue limit line and (?almost?) touching it, before you stopped accelerating and "really" overleaning. This (?almost?) touching the limit line was before tilt-back speed (note - the numbers for speed in the above diagram are not really km/h...)

 Here the "normal" graph of this near limit incident:

Did you already notice something or was it just good luck/gut feeling that you stopped accelerating?

ps.: this "limit values" come from my KS16S, and the values for lift-cut-off speed, "failure" factors for reported current,voltage can differ between our "same" wheels and the distance to the limit with yours a bit farther...

Thank you for your study of the log.
After the incident with the wheel I was constantly forcing it to try to reproduce the problem, accelerations and strong braking, but it wasn't repeated again.
I'm not a technician, I contacted Chris who sold me the batteries and the motherboard. Maybe I need to send him the wheel for testing. 

I'm sure this analysis you've made will be useful to him to diagnose the problem.

[Chriull]

1 hour ago, Augus said:

Thank you for your study of the log.

You're welcome!

1 hour ago, Augus said:

After the incident with the wheel I was constantly forcing it to try to reproduce the problem, accelerations and strong braking, but it wasn't repeated again.

The almost overlean was before the incident.

Just this "oscillation" was afterwards at the end of the log. Just out of curiosity i would be interested how you experienced this situation - how it started/?how you started this? And how it felt like.

[Augus]

It started suddenly two weeks ago, I don't relate it to anything. I felt very bewildered because I've ridden 7.500Km with this wheel, and I had never experienced anything like it.

Fortunately this happens at a low speed, and I have not had injuries, but I am very frustrated.

[Smoother]

I don't understand all the charts and graphs but I did question the near vertical acceleration spike that @Chriull mentioned.

I'm just throwing this out as something, or something like it, to think about.

My KS16S would cut out when it hit a bump.  I traced the problem to one of more poor connections at the control board with the Hall sensor wires. These wires are soldered directly to the board, so my dealer re did them for me and I've had no problem since then (early January)

The way I found the problem was to 1. logically consider the possible reasons for the problems, 2. Eliminate the easy ones (loose cable  connectors, etc) 3. until the smoking gun was found; wiggling the Hall sensor wires recreated the problem; wheel lost balance and started beeping.

I know you said it happens during mild deceleration, but this might simply be a coincidence, and acting as a red herring.(google it) 

 

Edited May 19, 2019 by Smoother

[Chriull]

6 hours ago, Smoother said:

I don't understand all the charts and graphs but I did question the near vertical acceleration spike that @Chriull mentioned.

Yes - that's the part where the wheel reports the exactly constant speed. So some problem for the wheel getting the right speed data which leads to the hall sensors...

6 hours ago, Smoother said:

I'm just throwing this out as something, or something like it, to think about.

My KS16S would cut out when it hit a bump.  I traced the problem to one of more poor connections at the control board with the Hall sensor wires. These wires are soldered directly to the board, so my dealer re did them for me and I've had no problem since then (early January)

The way I found the problem was to 1. logically consider the possible reasons for the problems, 2. Eliminate the easy ones (loose cable  connectors, etc) 3. until the smoking gun was found; wiggling the Hall sensor wires recreated the problem; wheel lost balance and started beeping.

I know you said it happens during mild deceleration, but this might simply be a coincidence, and acting as a red herring.(google it) 

He did not report of any correlation with bumps, but such a thing can easily be overseen if one concentrates on trying to stay on the wheel once it behaves such weird.

Besides the connectors of the hall sensor wires one should inspect the axle, where the cables come out of the motor, too. There the insulations of the wires like to ?fray/wear through?. Maybe they short just by acceleration/deceleration change?

@Augus after swapping your motherboard you fixed the connectors again with something like this "white gluey stuff"?

7 hours ago, Smoother said:

until the smoking gun was found; wiggling the Hall sensor wires recreated the problem; wheel lost balance and started beeping.

@AugusThat's s something you should try once you opened your wheel for inspection!

[Augus]

4 hours ago, Chriull said:

 

No, I didn't use white gluey stuff

Quote

@AugusThat's s something you should try once you opened your wheel for inspection!

Ok, I will

Edited May 20, 2019 by Augus

[Chriull]

34 minutes ago, Augus said:

No, I didn't use white gluey stuff?

I meant this stuff that was on your board before, fixing every connector and some other parts.

Edit: Photo: 

Here you see the hall sensor connector (just above the big green capacitor) at my previous KS16B/C board with the white stuff fixing it. I am not sure if this is really necessary, but there are quite some vibrations/shocks happening with the EUC...The other connectors for LED's, speaker etc are not fixed with this stuff, and they never got loose...

And another idea/question: afaik ks wheels show hall sensor faults with the led rings. If i remember right it was the first and last led of each stripe lighting in red. Did you notice such a pattern when you had these incidents happening?

Edited May 20, 2019 by Chriull

[Augus]

Ok, I will reinforce the connector with that silicone paste.  I did not notice the led lights,  I'll look at it next time.

Edited May 20, 2019 by Augus

[Smoother]

On 5/20/2019 at 8:02 AM, Chriull said:

I meant this stuff that was on your board before, fixing every connector and some other parts.

Edit: Photo: 

Here you see the hall sensor connector (just above the big green capacitor) at my previous KS16B/C board with the white stuff fixing it. I am not sure if this is really necessary, but there are quite some vibrations/shocks happening with the EUC...The other connectors for LED's, speaker etc are not fixed with this stuff, and they never got loose...

And another idea/question: afaik ks wheels show hall sensor faults with the led rings. If i remember right it was the first and last led of each stripe lighting in red. Did you notice such a pattern when you had these incidents happening?

The Hall wires are hard wired to the board, and the factory goo is necessary, but, as in my case, possibly  ineffective, because around here is where my disconnect occurred. All the vibration the wheel feels from riding over rough ground is transmitted directly to the board and the wires.  When I got my board back, I taped the wires to the capacitor to further reduce movement, because otherwise they were free to flap about.  Every bit helps.