Magic pie 3 modding.

[Judd90]

hey guys just a few questions in regards to the Magic Pie 3,
I can't seem to find a lot of information on how/what I should be doing to let my pie take more voltage/amps as well as how to test the hall sensors in my motor.
I have recently purchased a 48v 45A controller from ballarat electric bikes in Australia because I'm led to believe my internal one has just died for no reason (bought hub and internal controller second hand)and its got me thinking while I have my hub opened should I be upgrading the phase wires and drilling holes in air flow holes in the casing so that it keeps it nice and cool at higher temps? I got told I would have to "wind" the hub and do something with the gears? in any case even if I only upgrade the phase wires what size should I go to and which phase wires are which? does it matter where you plug them into the controller, sorry I'm new to all this. thanks for the help!

[Bikemad]

If the external controller draws an actual 45 Amps at 48V, the 2.2kW should make your Pie powerful enough to produce  wheelspin under heavy acceleration at low speed (and hopefully a lot of drifting fun when it doesn't spin).

You will obviously need to use longer phase wires to reach your external controller, so it might be a good idea to use 10 gauge wires or even thicker if possible to reduce the voltage drop across the wires. The Phase wires are usually colour coded Green, Yellow and Blue (the same as the Hall sensor wires) and it is very important to get them all connected correctly to avoid damaging the new controller.

There are 36 possible combinations of the Phase and Hall sensor wires, but only 3 of those 36 combinations will allow the motor to run correctly in the forward direction.

Drilling holes in the side covers should allow better cooling, but it will also allow bugs, water, dirt, small stones and grit etc. to make its way into the motor. I would be tempted to try the motor without any cooling holes first to see just how warm the motor gets during use. If it does get very warm, then you can perhaps consider drilling holes to improve the cooling.

As I live in the UK, we don't often experience high ambient temperatures, so I would be more concerned about water getting into the motor. I would suggest using some suitable rubber grommets to fill the holes and hopefully keep all the nasty things out of the motor when the weather is not hot or the motor is not being used.

Unless you enjoy major hassle (and are prepared to risk ruining your motor completely) I would completely forget any thoughts about rewinding the motor.
With a 48V battery, and the standard windings, it should be more than fast enough to cause plenty of minor injuries. 

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

Alan
 

[Judd90]

Thanks heaps for your help Alan, I will swap out my phase wires for some 10gauge ones later on in the week now that I know what size should be fine for those amps. And I think il do what you said and just see how it goes without drilling the holes and see how the temperature goes. And that video was really helpful thanks. Never thought to just type in hall sensor test bescause of how many other things have hall sensors. Always typed in hub motor hall senaor and didnt find any helpful ones. yhanks again Alan

[Andrew]

Try and get teflon coated wire for phases. It is strong/tough and will take warm temperatures.
I would say 12awg would be enough. With thicker wire you may have problem with threading the phase wires and hall wires through the axle.

[Bikemad]

With thicker wire you may have problem with threading the phase wires and hall wires through the axle.

The MPIII does not have the wires running through a slot in the axle under the bearing like the earlier Pies had, so it is much easier to fit thicker wires if you want them. The only clearance problem you may encounter is where the wires are secured to the axle in the centre of the disc brake mounting (cooling fan assembly).
If the wires were much too thick, the inside of the brake disc mount might rub against the insulation of the wires and cause problems.

If you are not using a disc brake (or an internal controller) you could simply remove the cooling fan assembly altogether and use really thick cables if you wanted to minimise the voltage drop on the phase wires between the external controller and the stator windings. 

Alan