All of a sudden, this happened today.. Help!

[Sangesf]

Well today I was riding my bike and the front motor (24v mini) all of a sudden started go full throttle for no reason. So, I turn off the motor, turn it back on and it beeps at me twice and now no longer turns..

I've looked at the manual for the magic controller and have tried every combination of brake/cruise button/throttle combination and nothing works...   Just to check it out, I take my other controller and hook it up to that motor and nothing..  I hook up the original front controller to the back motor and nothing...
So, it looks like the controller and motor are screwed..   What do I do at this point?
P.S. I re-hooked up my rear controller and motor and it works fine..  It's just the front motor and controller, no longer work

[Bikemad]

Frank, 2 beeps = Motor hall sensor fault (or confirmation during motor phase calibration).

A broken throttle ground wire or a poor connection in the ground circuit could cause full throttle.

It's possible that the controller could still be fine, and the reason the rear motor didn't run using the GM controller might be due to different phase settings.

If it hasn't been overheated, it could just be that one or more of the hall sensors has failed, but unfortunately the minimotors don't like running in sensorless mode as you cannot manually start them spinning like direct drive motors.

If you disconnect the hall sensors wires from the controller, and swap 2 of the phase wires over, you might be able to make the wheel motor run backwards in sensorless mode by spinning the wheel backwards and applying some throttle. If it runs backwards, this could be an indication that the controller has not failed.

It might be worth checking that you still have ~5V between the red hall sensors supply wire and the black ground wire, and then try and check for voltage variation between each of the hall sensor signal wires (Green, Blue  and Yellow) and ground (Black) while slowly turning the wheel backwards.

If just one sensor has stopped working I would say it's just a sensor problem. If all three have failed, then it could be the result of an excessively high voltage being sent from the controller instead of the nicely regulated 5V.

To check the windings, compare the resistance readings between the disconnected phase wires, all three readings should be similar.
(Green - Blue, Blue - Yellow and Yellow - Green)

I don't know what else to suggest other than rechecking all the obvious connections between the hub and the controller.

Alan
 

[Sangesf]

Alan,

The rear motor is currently using the same controller as the front. (I have two GM Magic controllers) that's why I tested the front controller on the back motor and the back controller on the front motor

So I know both the motor (front) and controller are non working.

How do I go about an exchange?

FYI... a small update..   I got the front wheel to move about 3mm once and only once (using my other controller and the rear motor connections) so I know both controller and motor are kaput! ;(

P.S. Even if it's only one or more hall sensors, the wheel is useless to me since the minimotor won't work in sensorless mode. (maybe that's something GM should make known abou the minis)

[Bikemad]

How do I go about an exchange?

I have not needed any warranty replacements etc. but if you send an email to Tom (zhourenli@goldenmotor.com) containing the original order number and an explanation of what has happened, he will hopefully explain what needs to be done.

It might be worth contacting your local GM dealer to check what the normal warranty procedure is.

Alan
 

[Sangesf]

The dealings I've previously had with both. "local" dealers have not gone well..
I would MUCH rather deal with GM Directly.  

I tried what you said with swapping the phase wires on the "broken" controller (using all the rear motor stuff except for the phase/hall wires {obviously}) and nothing happened
then tried it with my other (rear) controller and I could hear the internals moving (however obviously the freewheel didn't let the wheel motor turn)

so still both controller and motor are non functional

[Sangesf]

Using the controller I know is good I hooked up everthing except for the hall sensors to the front motor and checked if there is any voltage between the red and black hall sensors coming out of the motor and it read 0 volts...

Is that the correct way of what you said? Or do I have to hook up the halls to the controller and test again?

[Bikemad]

Frank, the 5V supply to the hall sensors comes from the controller, not the hub, so you would need to have the hall sensors connected and the battery turned on in order to check the voltage being supplied to (and the varying output voltages coming from) the sensors.

With the front controller connected, it should supply ~5V to the Red hall sensor lead and the Red throttle lead.

A reading which is considerably higher than the expected 5V would indicate that the controller's 5V regulator circuit has failed, possibly resulting in damage to the sensors in both the hub and the throttle control, due to the excessively high voltage.

On the other hand, a reading of 0V would also confirm that the controller has failed.

I would not recommend plugging the good rear controller into the front hub, because if the sensors or wiring have become short circuited, you could risk damaging the good controller as well.

If the hub failed first, it may have caused the failure of the controller (and Vice Versa).

Alan
 

[Leslie]

This is the good thing about a reliable sensorless configuration and where new protections in the controllers like auto sensorless mode in the controllers may fail on a hub that is suspected to not support sensorless mode.

Bikemad, you posted before about the possibility of the mini motor not supporting sensorless mode.  Can you discuss why this is so and possible ways you can think of around this limitation.  


What happens to a mini motor and its controller when the Hall fails?  Does the controller attempt to still run the motor?

Both stator and magnets in the minimotor are void of both freewheel and gears interfering with polarity and phase detection, do they not?  Its only a problem with reverse.

On the theory of MCU failure to complete the algorithm instructions for induction monitoring and sensor timing to the IO latencies required by the faster geared motors I theorise this.  

The motor should run up to a certain speed sensorless then logic processing (instructions per second) fail at the MCU,  but its already switched to sensorless mode so no fail safe has been considered, the phase timing stumbles and just might generate enough resistances of each switching event between all phase channels, moving magnets yadayada to deliver serious spikes to the fets.  The magic controller might have evolved out of the Mini motors range of compatibility.



Maybe the symptoms of timing failure should initiate a sub routine.  Execution of a phase event should only be executed if certain parameters are met or a trigger IO event is high at a pin.  A pin could be allocated to trigger a sub routine when a certain voltage is reached between source and ground.  EG a voltage spike, I still have no idea what the software is doing inside the chip. But if the MCU is bogged down this may fail to make a difference. 

This would be useless in a power failure event, as no power no software or even if the processor is overloaded, but for sensorless this idea could prove essential in the years to come.  There be a hundred ways you could do this even in hardware.  The old relay in the old controllers would not be even close to fast enough and solid state relays are bulky and can get hot.

I hope the engineers are paying attention to the few but random failures, 100 volt fets would certainly solve a lot of failures, but not everything.

The GM controller has become very advanced in many functions and possibly the most advanced ebike mainstream controller on the market.  If I had these skills I would build my own controller now but I would aim for something much simpler and less challenging.

Honestly I'm in for some purchases this year and I keep ending back here.  But I want to make the right choices for my daughter here to avoid her my problems.  However as much as I like hacking this technology I want things to go smooth this time around.

Does the mini motor support sensorless mode or are there limitations, like it works ok at 24v?

[Leslie]

a second MCU kept charged by a large cap for fail safe, health monitoring operations may prove to be a forward move.  If your going to turn these controllers into computers I say copy from the sucesses from others.  Most computers these days have the BIOS separated from the software due to processor power  limitation matched to variable user input damaging hardware, it's like don't depend on windows to monitor and control your fan speed, it may fail when you overload the cpu.  

In this case the confines are not limited by the terrain or the way a person rides a bike. A single MCU with a finite roll yes and even be suitable for an ebike operations but some shut down mechanism needs to able to survive for regen in a circuit break event or MCU lockups or stack overload. Or even just by chance the MCU looses sync with phase timing.  

[Bikemad]

Bikemad, you posted before about the possibility of the mini motor not supporting sensorless mode.  Can you discuss why this is so and possible ways you can think of around this limitation.  

In sensorless mode, the motor usually needs a bit of a helping hand to start it spinning before the controller can take over properly. This is fine with direct drive, because as soon as you start pedalling, the motor starts turning, and presumably voltage pulses from the phase wires are picked up by the controller until it eventually realises what's happening and then starts to take over.
Because of the internal freewheel device inside some minimotors, the above does not happen. As the motor cannot be manually rotated in a forward direction, there are no pulses being generated for the controller to respond to.

If the controller could somehow be reprogrammed so that in sensorless mode it would send a pre-set series of phase pulses in the correct order, this would hopefully start the motor spinning as soon as the throttle is first operated (but only if pulses were not already being received). I expect you would still need to pedal the bike slightly to remove any driving load from the motor until it is able to start running correctly by itself.

As I have no experience with programming speed controllers, I don't know how feasible it would be to implement this idea.

I hope some of this actually makes sense to you.

Alan
 

[Leslie]

Ah I see.  Thank you for your reply.

Yes I consider that in sensorless mode 0 start take off isnt off the board but in some cases it doesn't happen but in the mini motor there is every chance this will never happen.

As Ive said before when I cut off 20 (cutting shunt) amps to my hub it stopped the coils from any saturation allowing the sensorless to work correctly no pedals, take offs required no pedaling at all, with a direct that is.  Maybe things might improve with the mini motor if current was limited to 12 amps, the mini motor and magic controller are david and Goliath at times.. The fets in that baby are 120 amps each.

When I went to 60v saturation started setting in again the take offs became a little iffy.  Occasionally needing to move her a little.

Other things Ive noted is low voltage and SLA slumps can play up with sensorless functions.

[Leslie]

Though the magic controller could take a 7mm short coil beasty stator, going higher volts seems a waste and a lot more internal resistance to deal with in packs.

Oh my god at 60v my old SLA has some internal resistance working against me.  Im thinking going low volts high AH and chunky short windings is the way to go.

Larger AH batteries have lower internal resistance and less cells have lower internal resistance and so does a motor wound for lower volts.

[Sangesf]

Got an email back from Tom...

Basically I'm screwed.... 

The only warranty these for a year, so I'm stuck with a dead wheel/motor.

I spent over $300 and got a motor that only lasts a year, that just SUCKS!

[Leslie]

Got an email back from Tom...

Basically I'm screwed.... 

The only warranty these for a year, so I'm stuck with a dead wheel/motor.

I spent over $300 and got a motor that only lasts a year, that just SUCKS!

Youre not screwed yet.  Far from it.  You will probably find your motor and controller is fine.

If not there are ways to remedy this easy.

You need to get service now.

When you get full throtte this means the connection has failed.  This make this is sound and take out every possibility one by one.

Ok youve checked all that.

There was a thread with one good guy who locked up the free wheel on his bafang and got sensorless on a geared free wheel working fine.

Consider these things.  They may be hard to obtain and do at first because there is no Ebike service centre down the road.  So it can only be up to you or pay for repairs.  Would be cheaper to work it out yourself.

The more you look for ways around your obsticals the clearer the path should be over more time.

Yes it sucks.  I felt like you did when 2 weeks and my hub was fudged after my bike fell over on gravel and mundged my wires.  I blew controllers from faulty connections' and blew chargers up from reading wire colours and I had my probes on the wrong polarity doh. 

Honestly you have done well if you done a year with no problems.  We just need to figure out a way to get your motor working with two beeps.

Keep in there dude.

 

 

[Sangesf]

Well, I need to know how to lock the free wheel on the motor and ok, that'll fix that....
The controller is hosed tho... so I need to get a replacement one.
Will TRY to get a replacement one through my "local" GM dealer, but they've already sent me a bad one before, which I needed to get replaced and that took me two weeks after having to call GM directly in China to get the local dealer to send me a replacement unit.
FUN, FUN, FUN....
NOT

So, where do I find a way to lock the free wheel?