MP3 how to open cover?

[MAGICPIE3FOCUSPOWER]

Can anyone explain or has any pictures how to open MP3 side covers?

Thanks in advance!

[MAGICPIE3FOCUSPOWER]

No one?

Thanks!.

[ThunderhorseMaker]

I too would like some pictures, advice, or instructions on this matter also.

Now that I must replace hall sensors: opening the MP3 is a must for me.

There must be someone of there who has done it by now!

[Bikemad]

If you simply need to access the controller, you will have to remove the cooling fan assembly first, as shown in Gary's video.

To gain access to the Hall Sensors, it should be possible to remove the cover and cooling fan as a single unit, without having to disturb the controller and its connections.
 
Mark the cover in relation to the hub using a marker pen or similar and then remove the nine cover retaining bolts.

Thread the axle nut onto the the axle on the freewheel side until the side of the nut is level with the end of the axle and then give the nut/axle a big smart tap using a wooden or rubber mallet (or a block of wood and a hammer) to loosen the joint between the cover and the hub on the controller side.
If the joint doesn't separate first time, hit the nut/axle a bit harder and hopefully the joint will eventually separate. If however, the silicone jointing compound is too stubborn, and won't allow the cover to separate from the hub, you may need to resort to using a thin flat bladed screwdriver to carefully prise/force the joint apart, just like Gary did with the controller cover in his video.

Once the joint has been separated, the side cover assembly should then slide off relatively easily, revealing the stator assembly and the windings. If it doesn't want to slide easily, and you can find a couple of long bolts to thread into the disc brake fixing holes, you should be able to easily screw them in evenly and extract the cover.
Make sure the bolts are positioned well away from the main wire going into the controller as you won't want to damage that.

It might be possible to change the Hall Sensors without having to remove the stator assembly, provided they pull out of their locations easily, but it might make the job a lot easier by removing the stator assembly completely.

To do this, place a piece of old carpet, or some towels or thick cardboard etc. on the ground to protect the paintwork, and then place the wheel in the centre with the axle vertical and the controller housing uppermost.

You now need to push down on (and climb onto) the wheel rim, whilst trying and keep the stator centred within the magnets so that it will hopefully allow the hub to slide down the axle until the stator is well clear of the magnets.

DO NOT PUT YOUR FINGERS BETWEEN THE STATOR AND THE MAGNETS.
THESE MAGNETS ARE EXTREMELY POWERFUL AND COULD GIVE YOU A NASTY NIP IF YOU WERE TO RELEASE THE PRESSURE ON THE RIM!

You should be able to hold the stator by the axle and simply lift the whole assembly out, assuming you're not too weak after wrestling with the wheel.

Alan
 

[MAGICPIE3FOCUSPOWER]

Alan thanks!

 

[MAGICPIE3FOCUSPOWER]

I managed to open the cover with the big bearing.
But how can I remove the cover with the little bearing?

Thanks!

I have found this, but still can't open it.

Is there a way to adjust or tightening the mp3's axle/bearings?

Unfortunately the bearings are not adjustable, as they are simply held in position on either side of the stator by the two side covers.
Here are some photos of my MPIII's bearings:

The left hand bearing has an unusually large inside diameter (85mm) to allow it to fit over the outside of the stator's tubular extension piece that houses the speed controller.


The right hand bearing is the same size as the earlier Pies, and it appears to have some form of locking compound holding it firmly inside the housing:

The inside of the bearing fits nicely over the machined surface of the axle next to the circlip:


I think the most likely place for any play to occur will be between the inside of the large bearing and the cylindrical part of the stator, but you will probably have to remove the disc brake mounting/fan assembly in order to see it more clearly.

Any play developing between the bearing and the stator assembly would result in movement as indicated by A and B on this photo of an early Magic Pie:


Alan

[Bikemad]

I managed to open the cover with the big bearing. But how can I remove the cover with the little bearing?

I want to replace the internal MP III controller, because I don't trust it anymore
The  5V output is very unstable, also it will travel from 2V to 5V.

If you're only replacing the controller, I don't understand why you would want to disturb the nicely sealed side cover by removing it.
Simply removing the controller should have been sufficient to allow adequate access to the phase wires and the hall sensor wiring:



However, if you have tested the hall sensors and found one or more of them to have failed, it would be better to leave the remaining side cover in place and remove the stator assembly instead, so the bearing in the centre of the cover can be used to keep the stator more centralised, which should greatly assist you in guiding the stator through the magnets during the process of removal and refitting.

To remove the stator, place a piece of old carpet, or some towels or thick cardboard etc. on the ground to protect the paintwork, and then place the wheel in the centre with the axle vertical and the controller housing uppermost.

You now need to push down on (and climb onto) the wheel rim, whilst trying and keep the stator centred within the magnets so that it will hopefully allow the hub to slide down the axle until the stator is well clear of the magnets.

The magnets are very powerful and it will require a fair bit of force before the stator will come away from the motor housing.

DO NOT PUT YOUR FINGERS BETWEEN THE STATOR AND THE MAGNETS.
THESE MAGNETS ARE EXTREMELY POWERFUL AND COULD GIVE YOU A REALLY NASTY NIP IF YOU WERE TO RELEASE THE PRESSURE ON THE RIM!

Once the stator is completely clear of the magnets, you should be able to take hold of the axle and then simply withdraw the whole stator assembly.

If you still need to remove the other cover for some other reason, you would need to use a suitable length of wood (a piece of an old broom handle etc.) and place it between the stator spokes and work your way around the outer portion of the cover, whilst gently tapping the wooden drift with a hammer or mallet until the cover eventually comes loose.

Alan
 

[MAGICPIE3FOCUSPOWER]

Thanks you!

Yes figured it out, just punch on the axle and the cover went off.

I was just curious what is behind the cover.

Also the big bearing is bad quality?
When you turn the bearing you can feel it's not running smooth....

How can I remove this big bearing?

[Bikemad]

I suggest you price up a replacement bearing before you attempt to remove the original one, as some of the ones I found were quite expensive.

Here are the relevant bearing details:



Replacing the bearing is unlikely to be an easy task, as there is no direct access to drift it out without possibly causing damage to the side cover.

It may be necessary to use a special drift of approx 86mm diameter, which should hopefully just fit inside the alloy casing and locate against the inner race of the bearing so it can be tapped out.
 
If the bearing has been sealed into the housing with bearing locking compound (to eliminate any unwanted movement) it will be much more difficult to remove.

It's possible that a press (either hydraulic or mechanical) may need to be used to gently ease the bearing out of the housing.

Alan
 

[MAGICPIE3FOCUSPOWER]

Yes I am aware of the price for the real brand bearing.
But the orginal one is only 30 USD.

Maybe I will put some grease in.
First I didn't now why the wheel is making clicking noise, now I know.....

[Adamsavage79]

Sorry to bump such an old thread. I'm wondering if you were able to remove the bearings and replace them ?

[Bikemad]

MAGICPIE3FOCUSPOWER has not visited the forum since 2014, so it might be better to send an email. 

Alan