Building the optimal motor!

Ok so with the DIY motor tread and the Doing the math thread already going this thread will be to get the basics together before I start my motor build from scratch..
I will build a scaled down version for the DIY chalange first to see what I can lern before atempting rear wheel motors for the srt4 and A Nitro Harley conversion!
The Goal will be low Rpm Hi efficiency Eg wheel motor and Iron-less core Iron core will be concidered.

My thoughts are if wound properly Hi efficiency is possible with out blowing controlers all the time. Eg the Diameter of the motor helps increase the torque whill using the same amps.
Is there an optimal surface speed for a magnet to pass a coil of copper??

Axial flux is definatly the most likely route I will go and possibly multi layer to get powerdensity up as well as efficiency.

Arlo
The thing that I learned to date on AF is that it depends on the load and the employment of the motor which characterizes the design.

• AF designs innately need to spin fast with small Radius-Arms.
• To produce higher torque densities then more stators are required, however the addition is not precisely linear – though it is more cost-effective to have at least two stators.
• Increasing the pole-count slows the motor down like any other motor.
• Weight of the motor is significantly reduced if using a coreless design, however more magnets are required, and likely they will be wedge/pie-shaped.
• Custom shaped magnets are very expensive!

Commentary:
I have noodled over this a bit and my hope was to get to a point where the design of a hub-sized equivalent could be developed, and to possibly enlist in a group-buy of magnets to drive the cost down. As it is – I do not have a single source for my design; the one online source that does give instant quotes is I fear hugely gouging. :|

The alternative is to develop a design using off-the-shelf (OtS) magnets which could create a significant savings at the cost of efficiency. <Shrug> Throw another stator in. :wink:

With DtM thread, we still have to discuss the Alternate Non-Halbach Design, as well as the Rim-Motor Design. I’ve been off-line with Eric doing other important calcs which we hope to report shortly.

With regard to Controllers, I too am concerned that the OtS units may not accommodate our needs: Sinusoidal waveform is required for Coreless, and you can wager that is an optional target in the BBC thread.

Best, KF

Arlo did u check axel borgs book ? He has diy axail motor.

Im going to dedicate time to reading evey thing I can. What about magnet shap vs winding shape vs size ect. is that any simple rules to folow?

Arlo,
I suggest reading what I’ve read; the three books I have on the subject are:

• Electric Motors and Drives, 3rd Ed. By Austin Hughes, 2006; ISBN 978-0-7506-4718-2
  This was my “beginner book” on the subject in general, and very easy to grasp. A perfect stepping-stone.
  
• Brushless Permanent Magnet Motor Design, 2nd Ed. By Dr. Duane Hanselman, 2006; ISBN 1-881855-15-5
  A good reference on the covering the subject – though light on AF. Provides a huge reference of examples having various motor PM/Teeth relationships with appurtenant data.
  
• Axial Flux Permanent Magnet Brushless Machines, 2nd Ed. By Gieras-Wang-Kamper, 2008; ISBN 978-1-4020-6993-2
  Very deep on the subject at large in one technical pass. Bone-up on your math! Includes a CD-ROM of all book examples written for MathCAD. Leans a bit on industry examples – which I find limiting in comprehending the theory. Now that I have studied it from cover to cover I have more questions. :wink:

Best, KF

Thanks for this. I have 5 in my cart on amazon and I hadn't pulled the trigger just because they're are so many. There was a great electric motor/transformer book I used entitled "energy conversion" back in school but I think I borrowed it from a friend just for the class and I don't own it anymore.