# PMAC motor design ideas



## tylerwatts (Feb 9, 2012)

Folks
I'm trying to work out in my mind the optimum motor configuration for a single speed EV drive train. 

I'm working towards PMAC for simpler DIY manufacturing potential and have some questions. The design I am going for is an Axial Flux PMAC design. I read today that power transformers have different lamination metals with specific grain flow that promotes excellent Flux transfer in the direction of grain flow but poor in all others. So... 

Would it make sense to try use/recycle this material in my motor design? How? Should I 'roll' the steel into a cylindrical form to wrap windings around or should I stack flat plates to form the core Flux path? 

What is the best orientation of the core? I have seen MARS motors use dual stators with 'axial extensions around which the windings wrap but I want a single stator with dual rotors and a Halbach array of magnets for efficiency and amplified magnetic field. 

Please share views, experience and suggestions.

Thanks.


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## Zak650 (Sep 20, 2008)

Hi,
I'm putting twin me0913 motors in my VW Bug. I've never taken the motors apart but Ripperton in electric bike forum has more completely modified these motors than anyone else on the planet. From the photos on his thread it looks like the stators are made by winding strip material into a spiral donut, welding the donut to a backing plate, then cutting the stator winding slots. Cooling and more powerful magnets have been the biggest difficulties he has had to overcome making it into a serious track bike. Look at his thread and I'm sure you will learn a lot.
Zak

http://www.diyelectriccar.com/forums/showthread.php/ripperton-electric-track-bike-41173.html


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## tylerwatts (Feb 9, 2012)

Thanks Zac. I know the thread well and have followed his motor build closely. Not heard about the way the stator is built but it supports my ideas. Don't know what material is used. I imagine it too could use uniform-directional transformer lamination. Thanks for the info


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## Zak650 (Sep 20, 2008)

tylerwatts said:


> Thanks Zac. I know the thread well and have followed his motor build closely. Not heard about the way the stator is built but it supports my ideas. Don't know what material is used. I imagine it too could use uniform-directional transformer lamination. Thanks for the info


I don't know for a fact that they are made in that manner but I have 40 years experience in manufacturing and it seems the most reasonable way. You'd have to come up with sheared and coiled lamination stock which might be possible from a small motor manufacturer but I wouldn't bet money on that possibility.


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