Magic Pie 2 not working, sounds like motor is trying to turn but then doesn't

[boyced]

Hi, my Magic Pie 2 today stopped working, not it sounds like it want's to start turning but then doesn't, sounds like its vibrating all the lights on the handle bars are on.

does this sound like a hall sensor?

[boyced]

Feels like motor wants to turn backwards a little bit.

Been running fine for past week or so.

[Bikemad]

I would say it's going to be caused by a poor/incorrect connection, a failed hall sensor or the controller itself, although I'm not sure whether a single hall sensor failure would be sufficient to initiate sensorless mode or not, but if that were the case, it's unlikely to be a hall sensor problem.

If it's an external controller, you can simply unplug the hall sensors and see if the wheel will run in sensorless mode, but you will need to get it turning before sensorless operation can start working.

I have a few questions for you:

How did the problem start, was it during a ride after braking on a steep hill?

Is the wheel now difficult to turn (lumpy) with the power off or is it just as smooth as it's always been?

Does the motor only vibrate when you operate the throttle, or does it start vibrating as soon as the power is turned on?

I don't know what else to suggest at the moment apart from double checking the connections, especially if it has an external controller.

Alan
 

[boyced]

Which wire is the hall sensor?

it happened when going up a step mud hill.

the wheel does seem to wobble a bit, but I also noticed a couple of spokes have come unattached, so that could be why? isn't hard to peddle, also the brake doesn't seem to engage the regain either. That used to work.

the motor only vibrates when you engage the throttle

[Bikemad]

The hall sensors connect to the internal controller with five thin wires; Yellow, Green, Blue, Black and Red, which can be seen on the R/H side of the controller PCB:



The external controller has a single five pin connector in the same position:



Alan
 

[boyced]

excellent, I shall try removing that when I get home.  What effect will that have without a hall sensor?

[Bikemad]

Without the hall sensors, I noticed that my motor was very slightly noisier but you probably wouldn't be aware if it while riding normally.

The biggest drawback with running in sensorless mode is that the motor won't operate unless the wheel is already turning, so you won't be able to pull away on hills using the throttle without pedalling first to get the bike moving.

Alan
 

[Rodmiami]

 Boyced , Like I suggested to Wolfe , Check the battery charge and output . I have also had my MP2 quit on me . I ordered a new controller (internal ) that I did not need . I have had 2 batteries fail on me from GM . Both LiOn 36 v . The first one had the connector to the Battery Management System in the battery come loose when hitting a bump . Not knowing that happened I kept charging the battery which overcharged some cells and no charge for others . The battery would read 42v ( 36v battery ) but did not have enough Amps to drive the motor . The next battery a 36v 16a  LiOn  the BMS failed and would not charge the battery . My new LiPo4 36v 12a works like a charm . Just my suggestion . BikeMad rules when it comes to trouble shooting . Rodmiami

[boyced]

Hi, I tried unplugging the sensor. I have an external controller like the one you have pictured.

I don't have a multi meter handy to check the battery. But after the ride the battery charged for about 2 hours which is about right. So don't think it could be that. But it's possible.

Could the external controller be knakard? Do these things run hot as When I took it out if the bag when this happened it was hot

[Rodmiami]

  Sorry ,I have an internal controller . I don't know how hot it is suppose to run . Rod

[Bikemad]

As you've ruled out the hall sensors, check the connections on the three thick phase wires (Yellow, Green and Blue) where the motor connects to the main wiring harness, and where the harness plugs into the controller.

It would also be a good idea to have a close look at the main motor cable where it exits the axle to see if it has been chaffed through, resulting in a short circuit.

If the phase wire connectors are all OK, then I would say it's most likely to be a failed controller.

Alan
 

[boyced]

Thought I would check all the wiring, blue wire coming out of the hub is frayed. Blue motor wire is crimped then has black duck tape over the joint, the wire had Come out out. Im not responsible for this shoddy wiring I bought the kit on anther bike and transferred it over. All working now. Just need to dedicate some time to fixing this poor wring job

[boyced]

This is what the wiring looks like

http://i.imgur.com/QCRbu.jpg

There's a couple of spokes that have come undone, is this normal? May have to get some lock tight on the threads

[Bikemad]

Blue motor wire is crimped then has black duck tape over the joint, the wire had Come out out.

It's good to hear you've located the cause of the motor problem, it just goes to show how important it is to have good connections on the wiring.

There's a couple of spokes that have come undone, is this normal? May have to get some lock tight on the threads.

Loctite should not be necessary, if the spokes are correctly tensioned the nipples should not come undone.

Spokes will usually settle themselves in after a while and may straighten slightly at the elbow section causing the spokes to effectively lengthen and become loose.
When a spoke becomes loose, there is not enough tension to prevent the nipple from turning in the rim, and the nipples can gradually undo with vibration and movement of the rim during continued use.

If the loose spoke are not re-tightened, the nipples can eventually fall off the spoke completely and end up rolling about inside the hollow section of the rim.

Alan
 

[boyced]

can the nipple be reattached? is it in the space where the innertube is?