Pie flyed then died

[PJames]

Got my freewheel in so started to put bike together. Connected brakes, throttle, battery.
Turned on, lights lit up turned throttle the spinning wheel blew a gentle breeze across my floor.
All looked good. I bought a rack with a 48 v battery and the rack doesn,t work with the disk brakes (48v battery and rack not gm) went to look for bike rack at local bike store. Came home tried the bike again.
Turned on power , heard a ding lights turned on tried throttle nothing. Disconnected battery tried again same result, tried disconnecting brakes, tried other  throttle, checked battery 56.5 volts.
When I turn on the power I hear a ding from the motor. I did not hear this when it worked.
I assuming I have a short in the wires but where do I begin to look, I have about 6 feet of extra wire and think I will shorten it but would like to resolve this first.
Any ideas?javascript:void(0);
Thanks
 

[Leslie]

Does this ding happen as soon as you switch your controller on or when you apply throttle?

The ding IMO means your controller is attempting to power up one phase despite no throttle.

Hall sensor or sensorless logic module is putting a voltage feed straight into your fet drivers.  Or the fet driver on one or more channels are always on.


On my sensorless controller if my throttle was full on when I switched the power on, the sensorless controller would make the motor go ding and no spin.

Check your throttle cable connections are solid and test the voltages between the black and blue white throttle cable wires when twisting the grip to see if the voltage moves up and down between approx 0 and 4v.  

[PJames]

The ding occurs when power on the battery is turned on.
Tried the black/ white wire went from .8 volts to 3.7 volts.
After posting last night I looked at the bike again.I tried turning the wheel with the crank and found it difficult. I made sure nothing was rubbing. Went as far as to remove everything off(disk brake, free wheel)
and discovered that when turning it is dificult and feels like the magnets are catching. Was not like this before. Could I have turned on the anti-theft feature? Would it stay locked up when removed from battery? If so how do I undo that? Thanks for your reply  317537

[Bikemad]

When turning it is dificult and feels like the magnets are catching. Was not like this before. Could I have turned on the anti-theft feature? Would it stay locked up when removed from battery? If so how do I undo that?

I would be very surprised if you've managed to turn on the anti-theft feature, because I'm pretty sure that the wiring to the Magic Pie's controller does not allow for the anti-theft function to be made operational. (Unless Yao can tell us different)
If it was operational and worked in the same way as the external magic controllers, it wouldn't work without a constant battery supply anyway.

If the wheel is not fitted and you are trying to turn the axle by hand, it will seem very stiff to turn, but if the axle is fixed securely and you try and turn the wheel, due to the increased leverage, it should turn relatively easily.

If you disconnect the 2 pin power connector and the round 8 pin control cable connector and the wheel is still difficult to turn, it may indicate a problem with the speed controller itself.

If one or more of the FETs (power switching transistors) has failed in a short circuit condition, this could result in difficulty turning the wheel, similar to what you have described.

My advice is to send an email to TOM (zhourenli@goldenmotor.com) explaining your problem as clearly a possible and ask for his advice.

Alan
 

[PJames]

Would the wheel spin ratchety because of bad fets, even when unpowered?
thanks

[Bikemad]

Would the wheel spin ratchety because of bad fets, even when unpowered?
thanks

It's a bit like trying to spin a motor without a battery, but with the power leads touching together. This gives maximum electro-dynamic braking of the motor.
You can sometimes feel this braking effect with cordless drills. If you remove the battery pack and try to spin the chuck by hand it can be spun faster and easier in one direction than the other. If you switch the drill to reverse, you should notice that you can now spin it easier in the opposite direction to before.

I suppose that a shorted FET could make it feel more ratchety if only one of the three phases was acting as a brake, but I could be wrong on this.

If you rotate the wheel very slowly, do you feel much resistance, or does the resistance only become more noticable as you try to turn it faster?

Are there any noises (grating or rubbing)that might indicate signs of physical contact somewhere within the hub?

Does it spin any easier in one direction than the other?
(I'm not sure what this would prove, but it might be worth checking anyway)

If it was an external controller you could easily disconnect the three heavy duty phase leads to confirm whether the controller is causing the problem or not, but unfortunately with the Pie's integral controller this is not quite so easy to do.

Try and give us as much information as you can, because it's the only way we can "see" what's happening.

Alan
 

[PJames]

just as hard to turn either direction, resistance at all speed,
Thanks for the explanation, I guess that would explain the ding at power,
A blown fet is it easy to visual check?
Well email Tom

[Bikemad]

A blown fet is it easy to visual check?

It's not easy to see the FETs on the Magic Pie, even with the side covers removed.
If you haven't already seen this picture, this is what Hyena's controller looks like inside the Magic Pie:



Unfortunately the 6 FET's are on the other side of it and cannot be seen.
The thick Green, Blue and Yellow wires at the bottom are the motor phase wires.

Check out this post, which has similar symptoms to yours, but at least we know the cause of this.

And this one as well.

I'm not sure what has caused your particular problem, but I've a gut feeling that your speed controller will be faulty.
I do hope I'm wrong about this for your sake.

Alan
 

[e-lmer]

Shouldn't all the pies be under warranty still?

This should be a good test.

[GoldenMotor]

Yes all pies are on warranty.