motor died

[Hugh]

I was on a run on my trike and the motor died. I have the 1000 watt Magic Pie with the external controller. A cycle analyst is wired into the system and it was programmed by the GM staff for me since I could not figure it out. Anyway first the lead in. About a month ago the green wire  on the controller that's just below the power wires fell off it's spade connector. I had just gone a very bumpy gravel stretch. I noticed and reapplied the green wire but the plastic protector appeared burnt. This made me think it may have been loose and generating heat. Once it was reapplied all was good.

Till today's ride.  A few times heading out I got a shuddering feeling from the motor that felt like the disc brake was dragging. The reason I say that is when it was shuddering the motor struggled to get any speed. A few seconds then it would smooth out and act normal. But once downtown the shuddering got worse and the throttle no longer worked, nor the PAS system. Then the horn beeped 5 times. Shutting off the power then turning it back on and 5 beeps again. Now my trike has a separate pedal system so I could still move under my power. But there was a huge drag and a lot of noise coming from the motor so my wife was home and rescued me with the truck. Any thoughts on what might be the issue

[Bikemad]

Hi Hugh,

Unfortunately, five beeps is typically an indication that the controller has failed (usually when one or more MOSFETs has failed in a short circuit state). 

If the wheel is stiff and lumpy to turn, try unplugging the three Phase wires (ensuring they don't touch each other) and then see if the wheel turns normally again.

If the lumpiness (and the noise coming from the motor while pedalling) disappears, it will definitely be the controller that has failed, but I don't know whether the failure could have been instigated by the Green Phase wire connector coming loose. 

Alan
 

[Hugh]

Well I will order a new controller hoping that the motor will run again. I like the power delivery of the pie motor but was hoping for more than one season of riding trouble free. Thanks for the advice, hopefully it works.

[Hugh]

In the "ticket" system the good folks at GM sent me a link to a video showing how to test the mosfets in the controller. I did that and promptly ordered a replacement controller. Once it arrives the roof which had to be removed to fit the trike in my truck will be reinstalled, the front vent area will be closed due to the weather turning colder and it will be ready to ride again. Fingers crossed.

[Hugh]

Bikemad, you were right about the controller. I have been busy but swapped in the new one last night and the motor works again.

[Bikemad]

Hi Hugh,

It's good to hear that you've got your trike working again.
Fortunately for you, it's a lot easier to replace an external controller. 

If a MOSFET fails in a short circuit state with an internal controller, you can't easily unplug the three Phase wires to allow the wheel to turn easily again and continue riding using just pedal power. 

Alan
 

[Hugh]

Well the motor does turn so the controller works but something is wrong internally. Last night the wiring to the controller was tidied up and with zip ties the wires were fastened so as not to allow any movement. Today Oct 1 was a good day for a test run to the grocery store. The motor has  some initial resistance before starting and once underway makes a considerable knocking noise. It doesn't make that noise when the wheel is off the ground but with me in the seat ie weight on the wheel it is unrideable. Also noticed that previously even from a standstill the twist throttle would engage the motor, now you need to pedal to get the wheel turning before the throttle will work.
By unrideable I mean a loud knocking from the motor and I can feel the resistance as if some internal piece is rubbing. I only did a few circles around my garage because I did not want the new controller to malfunction.
I had opened a ticket and sent a couple pictures of the wheel and they replied it looked like my wheel has an internal controller, they thought someone had bypassed it to hook up the external controller. I know when I ordered it I asked for a Magic Pie motor with an external controller.

[Bikemad]

Hi Hugh,

Have you been able to sort the problem via the ticket process, and if so, what was the cause?

Regarding your "bypassed controller", it looks to me as if your motor might be a MPIIIx which may have replaced the older MP2x:



Your motor appears to have the later finned heatsink cover (but without any internal circuit board and electronics) similar to this pre-production version of the MPIIIx which used the original plain/smooth controller cover:





Is your wiring and external controller similar to that shown above?

Alan
 

[Hugh]

Actually the folks at golden motor.ca have been quite helpful, so no complaints about them. When I replaced the controller the motor turned on but differently than before.  Originally when the Grin twist throttle was used from a full stop the motor would engage instantly. When the new controller was installed I had to give the wheel a spin with my foot (this with the trike on jackstands) to get the motor to engage.
Then I decided to take it out for a ride and there was still a knocking type of noise from the motor itself and I could feel the resistance the motor had to turning. I thought maybe my disc brake mount could be the culprit so I removed the caliper, and the motor still had that internal noise. Note the noise is barely audible with the trike on stands but with a riders weight it is loud enough that someone standing nearby can hear it. The last reply on the ticket system asked for a video of the motor running but I am unable to provide that.
So I'm convinced there is something out of place internally in the motor housing that is rubbing. If I can figure out how to take the motor apart to look at it I might do so but I really don't want to throw any more money at this thing. I currently have one BBSHD equipped fatbike thats been running reliably for over 6 years summer and winter, another BBS02 equipped delta trike also running great for several years. This MP motor has let me down twice now, the first was my fault for not noticing spokes loosening. On that one I learned how to respoke and true a wheel so that turned out okay but this time I'm stumped.

[Bikemad]

Hugh, I have just been studying your previous photo and it looks as if the disc mounting bolts are too long and the ends of the bolts appear to have been rubbing against the ribbed cover, causing the visible circular (arc shaped) gouges:



Although the binding bolts would produce a certain amount of unwanted friction when the motor rotates,

Placing washers under the heads of the six disc mounting bolts should cure the binding problem, but I'm not convinced that this is the entire cause of your problems. 

When the motor does not run without first being spun, it is usually because the external controller is running in sensorless mode. (later internal controllers don't appear to have a sensorless mode.)
The external controllers will automatically switch to sensorless mode if they detect abnormal Hall Sensor input signals. This could be due to a failed Hall Sensor, or a break/poor connection somewhere in the Hall Sensor wiring.
The controller should automatically revert to sensor controlled mode once the cause of the abnormal Hall Sensor input has been rectified.

Ensure that the Hall Sensor connector is fully seated into the controller and then check the voltages (relative to the Black Hall Sensor wire) on each of the Yellow, Green and Blue Hall sensor wires to see if they continually alternate between 0V and ~5V when the wheel is rotated slowly by hand.
Take a look at this post and this video for more details on testing the operation of the hall sensors.

Also check that the three Phase connectors are tight and pushed fully onto their corresponding terminals (Yellow Wire -> Yellow terminal, Blue wire -> Blue terminal and Green wire -> Green terminal).

I am also concerned that the retaining clip that holds the cable against the axle is missing in your photo,:





Without this clip, the cable can rub against the inner edge of the disc mounting assembly and eventually chaff through the wires. 

A suitable tie wrap (zip tie) can be used if you no longer have the original retaining clip, but check carefully for any visible signs of damage to the cable before fitting the tie wrap.

Alan
 

[Hugh]

Good eye, I was trying to open up the motor and had removed that clip for the attempt. It was put back on right after. Everything seemed so tight that not wanting to break anything all the screws, etc were put back. You are right about the grooves from the disc brake screws. When I first bought the motor last year I ran it with the trike on stands for maybe 4 or 5 minutes. As soon as I noticed the screws washers were placed under them and about 2 months ago the proper shorter screws were ordered and installed.
The 3 wires are fully and properly seated on the terminals at the controller, I triple checked that as soon as the new controller was installed. Per your info that just leaves the internal hall sensors.

[Hugh]

My yellow trike has been dismantled and the Magic Pie motor is sitting against the wall. Since I have nothing to lose over the next couple months I will take it apart to see if I can troubleshoot it.