My Magic Pie went dead (Pairing Magic pie with ecrazyman 1500w controller)

[Avantgarder]

I disconnected the controller and measured resistance between the 3 power cables :
Green to blue : 0.3 ohm.
Green to yellow : 0.3 ohm.
Blue to yellow : 0.3 ohm.

Haul sensor measurements (Fluke is in Diode mode)

Fluke red pen to red haul sensor cable. Fluke black pen to Blue, Green and Yellow:
All gave 1.3 except Yellow

Fluke red pen to black haul sensor cable. Fluke black pen to Blue, Green and Yellow:
All gave 0.65 except Yellow

I opened the motor again and found that all the cables I routed are perfect.
The "yellow" haul sensor is dead.

Can anybody tell me the exact specification or brand of the haul sensor ?
It fits a ~ 2mm x 3mm notch in the perimeter of the motor

[Bikemad]

The Honeywell ss41 hall sensor is commonly used as a replacement and can be purchased from most electrical component suppliers, but if you can't find them at your local supplier, check out this post on ES regarding purchasing hall sensors.

I suggest you change all three sensors, not just the yellow one. The Honeywell sensors are "latching" (they remain switched until an opposite magnetic field turns them off again) so they might operate slightly differently to the existing sensors, using three matching sensors should ensure you end up with a smoother running motor.

Take a look at this post and this video for more details on testing the operation of the hall sensors.

If anyone is interested, this post has a link to a video demonstrating the difference in operation between a motor type latching hall sensor and a throttle type linear hall sensor.

Alan
 

[Avantgarder]

Thanks Alan,
I ordered 3 of the ss41.
Shipping from the US will take about 10 days to arrive and once they arrive I'll report my progress.

[Avantgarder]

Here is closeup of the notch for the sensor.
David from GM got back to me today and told me that in addition to replacing the defected sensor I will also need to configure my external controller for a phase of 120 degrees.

[Leslie]

Youre using that Ecrazy controller, Im prerty sure they default @ 120 deg,  that software is awesome.  Not the phase currents can be higher than the input current.  Sort a puts a spanner in the math regarding torque and voltage vs Amps. 

BTW its hard to test hall sensor.  Its good to power them on and test them the voltages between black and color wires rotating the wheel to see if all are working..

It sounds like you got a handle of all this Ebike stuff now and soon you will be riding trouble free...


I pulled my bike apart to rebuld as I thought my back rack was bent, it turned out my DIY rack was rock solid but the rear dual suspension was twisted due to the bike falling over loading the trailer all the time.  I solved the bike falling over thing by welding a bike stand to the trailer.  But I don't like this bike any more twisted a little. 

I have an old Currie Tech 26" MTB  gracefull Momma...  So I rigged my old ecrazy controller up, and internal converted to external MP and it didnt work, could be anything.  I looks to the spare GM MP2 with modded but original internal motor,  I Hard wires it and wooosh off she went.  This little internal MP2 was clocking up to 2500 watts on the CA. 

The MP internal controller is a little sluggish off the mark but my low to mid end torque is amazing.

[Leslie]

Youre using that Ecrazy controller, Im prerty sure they default @ 120 deg,  that software is awesome.  Note the phase currents can be higher than the input current.  Sort a puts a spanner in the math regarding torque and voltage vs Amps. 

BTW its hard to test hall sensor.  Its good to power them on and test them the voltages between black and color wires rotating the wheel to see if all are working..

It sounds like you got a handle of all this Ebike stuff now and soon you will be riding trouble free...


I pulled my bike apart to rebuld as I thought my back rack was bent, it turned out my DIY rack was rock solid but the rear dual suspension was twisted due to the bike falling over loading the trailer all the time.  I solved the bike falling over thing by welding a bike stand to the trailer.  But I don't like this bike any more twisted a little. 

I have an old Currie Tech 26" MTB  gracefull Momma...  So I rigged my old ecrazy controller up, and internal converted to external MP and it didnt work, could be anything.  I looks to the spare GM MP2 with modded but original internal motor,  I Hard wires it and wooosh off she went.  This little internal MP2 was clocking up to 2500 watts on the CA. 

The MP internal controller is a little sluggish off the mark but my low to mid end torque is amazing.

[Avantgarder]

I got the Honeywell SS41 hall sensors.
I have some concerns regarding my motor though:

1. The sensors I got are original Honywell SS41 sensors labeled "S41"
 The 3 sensors I have on my motor (only one is defected) are labeled "40P 822". Not an original ?
2. The honywell is trapezoidal and the ones I have are rectangular
3. The honywell is a bit too big for the notch I have. I don't like the idea of machining the metal so close to the delicate motor wiring.
4. Assuming I'll resolve the notch space issue, Should I have all of them replaced to the honywell ?
5. How do I connect the honeywell sensor ? Assuming the sensor label is facing away from the motor axis how do I wire the red black & yellow cables ?

[Bikemad]

I'm very surprised by the rectangular sensors, is there any chance you can post a picture of your stator?

The attached picture of my Magic Pie should help you identify the wires and orientation of the Honeywell sensors.

Alan
 

[Avantgarder]

Alan,
Thanks for the image. Which side of the trapezoid is suppose to face the axis of the stator ? the narrow one or the wide one ?

Regarding my stator, Have a look a few posts above your last post. I attached a closeup of my stator.

[Bikemad]

The wide side faces the axle and the narrow side facing outwards.

Unfortunately, the image does not show the recess in enough detail to determine whether the outline of the slot is rectangular or trapezoidal:



When I replace my hall sensors, they were bonded in so tight that I had to completely destroy them and remove them "bit by bit", and it was difficult to see the exact shape of the slot until I had carefully chiselled out every minute part of the smashed sensor (and the adhesive) using a tiny jewellers' screwdriver.
(A tiny screwdriver that Jewellers use, not a screwdriver borrowed from a tiny jeweller ). 

Alan
 

[Avantgarder]

Exactly the same problem I'm facing.
I had to chisel  the epoxy glue with a(n eventually destroyed) screw driver.
As for the notch I had  to machine it with a tungsten carbide burr which I "borrowed" from my dentist 
I widened it 1mm from each side to accept the slightly bigger ss41.
I hope the sensors exact location can withstand a tolerance of 1mm to the right or to the left...
What do you say Alan ?

[Bikemad]

What do you say Alan ?

I say you must have a very understanding dentist!

Anyway, try to position the sensor as close as you can to the centre of the original slot, but I don't think it will make a huge difference to the timing of the phase switching if they're slightly out.

Alan
 

[Avantgarder]

"understanding dentist"
lol !!!!

[Avantgarder]

I'll start from the end :  Finally I saw a little light in the darkness...My ebike is running !
Here is the process I had to go through + pictures:
In this picture you can see the result of the work with the tungsten carbide head. The notches are now wider and can accept the SS41 hall sensors.

DANGER !!!
WHEN USING THE TUNGSTEN CARBIDE BURR, MAKE SURE YOU PROTECT THE MOTOR COILS WITH A FEW LAYERS OF THICK TAPE.
THE BURR HAS A TENDENCY TO RUN LOOSE AND CAN DESTROY YOUR MOTOR.

[Avantgarder]

The next step is to fix the sensors to the notches with high quality epoxy putty.
The sensors must not be welded to the wires yet. Doing that will cause the sensors to move from a straight position. I learned it the hard way