Magic Pie died after 200 km bought 1 month ago!

[sdaniels]

Hi all,
after enjoying the pie for 2 weeks all of a sudden the motor did no spin anymore. After a couple of checks I found that the 5 Volt signal coming from the pie connector is just 1.2 Volts. There are no beeps coming from the controller. The 3 lamps on the battery gauge are on. I tried to reset (press brake and click 5 times the cruise control) but nothing happened. I read the forum and tried to troubleshoot. I did a shortcut from the +5 volt to the white throttle signal but the motor did not give a sign. So I guess the controller is gone. Any Ideas on how to solve the problem are appreciated.

I'm quite disappointed with the product. I was using it for 2 weeks and it is already broken.

[MonkeyMagic]

Hey sDaniels, does the cruise control button spin the wheel at half speed ?

Cheers

[sdaniels]

unfortunately not. no movement from the motor, no beebing nothing. I thinking of take a measure directly on the controller but I don't want to loose warranty. But I don't get any answers from GM. by the way do you know how to open the hub casing?

[Bikemad]

By the way do you know how to open the hub casing?

Start by removing the axle nut, washers and the nine fixing bolts on the freewheel side of the hub. The cover will come of with the freewheel unit still attached, so the freewheel does not need to be removed first. If you put a piece of tape next to one of the holes on both the hub and the cover you can make sure it goes back in exactly the same place.

With my Magic Pie, I found the easiest way to "break the joint" between the cover and the hub was to knock the centre of the axle on the opposite side with a large rubber mallet.
A block of wood and a hammer could be used instead, it's surprising how hard I had to hit it before it finally popped free, as there's a lot of mass in the stator which tends to absorb the impact.

Once the joint has been freed, the cover should come away with a little bit of gentle wiggling.
If the bearing is still too tight on the axle, try a squirt of penetrating oil and warming the cover up with a hair dryer and it may come away leaving the bearing behind if you're lucky.

Alan
 

[karen]

Found this post, might be helpful. Says something a bit down there about it...
http://goldenmotor.com/SMF/index.php?topic=2103.0

[sdaniels]

Ok got it open, thank you. No I measure the same 1.2 volts between the smal black and red lead. :-(.

So does this mean the controller has smoked?

Does anyone have a responsive contact in GM? I wrote already 3 mails to Nick also for some other topic, I never got any answer. The email to zhourenli@goldenmotors.com did not work and came back immediately.

Is it possible to fix the controller? Any Idea how to repair this 2 week old Magic Pie? Did some of you have similar problems and actually got support from GM? Do they give support or just sell and forget?

[karen]

loose the s in goldenmotors, and it should work?
zhourenli@goldenmotor.com
And I got help:)

[Bikemad]

I measure the same 1.2 volts between the small black and red lead. :-(.
So does this mean the controller has smoked?

It does sound like it might be the controller, but there's also a slim chance that it could be a wiring fault or poor connection. If the red lead has been damaged and is partially touching against another damaged wire or ground connection, this could cause the low reading.

I would first check for the correct battery voltage between the large red and black wires on the controller itself, before disconnecting (unsoldering) the thin red lead from the controller and re-checking the voltage between the thick black wire and the controller +5V contact.
If the correct battery voltage is being delivered to the controller, but the +5V contact is still only 1.2 Volts without the wire attached, then it's almost certainly going to be a faulty controller.

If however, the +5V contact does read ~5 Volts with the lead disconnected, then I would use an ohmmeter to first check the red wire for continuity, and then check to ensure it is electrically insulated from the other wires within the Pies wiring harness and the hub casing.

If you require further help with any of these checks, please let me know.

Alan

[sdaniels]

I did some measures directly on the controller.
Between the thick red and black I have 54 volts. I removed the small red from the print and measured again on the print on the ground and +5 and I get only 1 volt.

I'm quite sure some components on the controller have ceased function.

I will try to call the local dealer in order to get a replacement Magic Pie.

I wondering if it is bad design after all since I was using the bike under normal condition on a flat road. The motor was not under load or any stress, or if I just got a faulty product.

This is quiet frustrating ...

[Bikemad]

The results of your checks confirm that the 5V regulated supply on the controller has failed, but unfortunately the actual cause of this failure still remains unknown. This particular fault should not have anything to do with the load on the motor, and it may just be that a component on the controller has just failed for no apparent reason.

Without knowing how robust the 5V supply is, I don't know whether it would be damaged if the thin red wire was accidentally grounded somewhere causing a direct short. If the 5V supply has some form of built in current protection (eg. a suitable resistor), it should be virtually bullet proof and able to withstand a direct short, but I'm not going to check this by deliberately shorting mine out, just in case!

Tom has previously indicated to Karen that failure of the 5V supply can happen if you incorrectly connect the battery leads (Reverse polarity) but from your account of the failure, I would say this is definitely not the cause:

It worked perfect for 2 weeks, then all of a sudden after a few flickering lights on the battery gauge the motor does not work anymore.

I still don't understand why the battery gauge lights would have flickered, unless there was an intermittent connection somewhere on the gauge wiring.

I think you will just have to wait and see what your local dealer has to say regarding a warranty replacement .

Alan
 

[TRK]

Could the flickering lights of the battery gauge maybe indicate a grounding problem?  Perhaps the black wire is the problem instead of the red wire?

[Bikemad]

Perhaps the black wire is the problem instead of the red wire?

As the throttle and battery gauge share the same common ground wire to the Pie, it could be a possibility. 

If the common ground failed (leaving the throttle and battery gauge still joined together, but isolated from the ground connection), the 54V from the battery gauge might have travelled through the gauge and then back through the throttle hall sensor in a reverse direction (assuming that it's possible), and then along the thin red wire to the controller, causing damage to the +5V regulated supply!
                                                                   
I think there's a good chance that it may have happened this way (it would certainly explain the flickering lights on the battery gauge), but I'm not prepared to test this theory out on my Pie either.

If the controller has a resistor specifically to protect the 5V supply, I suspect that putting 49Volts (54V-5V) directly across it would be a bit too much for it to cope with.

Alan
 

[sdaniels]

Somehow it looks to me that these kind of failure should be discoverd in a test phase of the components. I'm also expecting the device to be designed robust so that it can handle certain shortcuts. Maybe not 10 times the normal input voltage, but still I consider the product as "Early Life Failure".
When I had a look at the controller I found that the 3 thick leads yello, blue, türkis had been scratched on the isolation due to some force applayed from the plate where the controller is mounted on.

For me it looks like there is no big chance that I can fix the controller my self. I'm looking forward to get an answer from Tom soon and maybe the forcast of a replacement wheel, but unfortunately non of the official Goldenmotor staff nor the local dealer here in Switzerland is answering on email or telephone.

I'm still hoping to get the bike up and running one day an not that I have to ship back everything!

[MonkeyMagic]

Hey sDaniels Son

Any updates? I'm thankfully all sorted. Hope you get back on the road soon and your Pie doesn't get stale...

Let us know how you go

[sdaniels]

Hi Monkey Magic,

I called local dealer but they are not gonna replace the faulty pie. They do not know anything about that the official warranty cards says that one should contact the local dealer.

Unfortunately no replay from Tom. I don't know if I should start a refund on paypal or not. I'm not sure if I'm to inpatient but the bike is now unused for a week and I don't have any direction on what I can do or if they will replace it or not.

Hope it is gonna be a happy end