Author Topic: Problem with Magic Pie 2  (Read 7374 times)

Offline Gabriel

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Problem with Magic Pie 2
« on: March 08, 2019, 03:25:04 PM »
Hi, I´m new in this Forum. I´m Writing from Argentina. Where I used to ride mi bike from home to work.
Last Week I was riding my bike travelling to the center of the city and it stopped working. With no sounds ( no beep).
I disassemble my motor, and opened it. So I want to check the windings desoldering the 3 phases wiring ( Red-Green-Blue). To tester them with a multimeter.
I don´t remember if my motor is 750W o 1000W, it use 48v.

My question is if you can help me to understand the measurement that multimeter have to inform me.  I use the multimeter in resistance mode and it informs me only 2 ohm, between the wires.

Is the correct measurement? Can you inform me the right way to tester de windings?

Thank you!!!!
Gabriel

Offline Bikemad

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Re: Problem with Magic Pie 2
« Reply #1 on: March 08, 2019, 07:33:54 PM »
Hi Gabriel andto the forum.

I have yet to see a Magic Pie with failed Phase wires as they have proven to be very robust, therefore it is much more likely to be a fault with the throttle, internal controller or a failed Hall Sensor.

2 Ohms (or even less) across each of the pairs of Phase wires is probably about right.
If all three readings are similar, this is usually a good indication that the phase windings are good. But if one reading is a lot different to the other two, this could indicate either a short circuit or an open circuit in one of the phase windings.

Incidentally, the Phase wires should be coloured Green, Blue and Yellow, not "( Red-Green-Blue)" as the thick Black and Red wires on the bottom left of the controller are for the Battery supply:



Not all internal controllers were fitted with the audible beeper unit shown in the above photo, so you would not hear any beeps in the event of a fault, if your controller is like this one and doesn't have one: ::)



If the wheel was very difficult to turn after the motor stopped working, this usually indicates controller failure., and the wheel should become easier to turn again with the Phase wires disconnected from the controller.

All I can suggest is that you check the operation of the Hall sensors and also check the throttle signal voltage on the controller to confirm they are both working correctly.

Each of the Hall Sensors outputs should alternate between 0V and 5V as the wheel is slowly rotated in relation to the stator.

The throttle signal voltage should go from ~1V to ~4V as the throttle is activated.

If the Hall Sensors and Throttle signal readings are correct, it is likely to be a controller fault.

Alan
 

Offline Gabriel

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Re: Problem with Magic Pie 2
« Reply #2 on: March 19, 2019, 08:18:09 PM »
Hi Alan, thanks for your response!!!
This World need people like that disinterested help others to solve problems.

I will test your recommendation with my motor and I will inform the results.

Sorry for my english, I know it's not the best.

Gabriel

Offline Gabriel

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Re: Problem with Magic Pie 2
« Reply #3 on: May 16, 2019, 06:15:31 PM »
Hi Alan, finally after my holidays made the tests.
I´ve disconnected the phases of the controller, and then when I try to turn the whell It rotates ok. So I understand that the problem could be the Controller.
Do you know where I can buy a controller, of if there are any way to test some components of it? I´m electronic technician, so I can make any test but I don´t know where to start.

Sorry for my english, and many thanks  :) !
Gabriel

Offline Pwd

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Re: Problem with Magic Pie 2
« Reply #4 on: May 19, 2019, 03:33:00 PM »
I don't have an electrics background but I have been playing with ebikes for a few years now. When a controller fails, it is usually the mosfets that fail, especially with the symptoms you had (the wheel became easier to turn after disconnecting the phase wires).

Check out this video for troubleshooting:
https://www.youtube.com/watch?v=lTssCn5YyTw

Golden Motor Canada doesn't appear to have any replacement controllers in stock. If you can't find one, it is pretty common to convert these motors to use an external controller. Did you purchase it from a Golden Motor dealer? Perhaps it may be covered under warranty?

Good luck


Offline Gabriel

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Re: Problem with Magic Pie 2
« Reply #5 on: May 19, 2019, 04:56:33 PM »
Hi PWD I´ve got my ebike used here in Argentina I was using it since 2016.
I´ve checked the tutorial it is really excelent. I will test with the internal controller of Magic Pie 2.

So I need to know if I can found the MOSFET model here in Argentina.

Thanks.
Gabriel

Offline Bikemad

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Re: Problem with Magic Pie 2
« Reply #6 on: May 19, 2019, 09:48:25 PM »
Hi Gabriel,

The MOSFETs used in my original Magic Pie controller are marked P140NF75 which you might be able to obtain from your local electronic components supplier.



If you are not able to find some locally, I found 10 of them on AliExpress for US $4.50 with free delivery, but they could take a while to be delivered from China as the estimated delivery time is 22-41 days.  :(

I thought that the video was very informative, so I have also added a link to it in my "Useful Links" list.

Alan
 

Offline Gabriel

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Re: Problem with Magic Pie 2
« Reply #7 on: May 19, 2019, 10:56:32 PM »
Sorry, this is a glue? What is this use for?
« Last Edit: May 24, 2019, 06:48:26 PM by Gabriel »

Offline Pwd

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Re: Problem with Magic Pie 2
« Reply #8 on: May 27, 2019, 02:41:59 PM »
It is just an insulating pad and comes off easily when the three screws are removed.