[major]

I have some ideals about building my own motor for a ev even though it is popular just to fork out the cash and buy one. I wanted to run my thoughts out to the public for a perspective other than my own on the subject. Here is what I was thinking about doing.

I was thinking about using sheet metal and make a plate diagram. Then cut a bunch of plates out using that diagram and sand the sides down on the plates to make ever thing nice and neat. Then taking those plates and stacking them to make my rotor. Then spot welding, braze solder what have you to stick all the plates together. Then wind the coils around the rotor.

Using sheet metal again and a spot welder, braze, solder what have you I would then make a stator and wind coils around that. I dont want to use magnets because I want this to be able to run at higher tempatures.

My only problem is I have to finish the design aspect of this and how all this would fit together. I want to be able to use more than one motor on the ev because I need to use a little more power.

I have some other ideals but am only talking about the motor for now. Does anyone know how I would go about completing a design for this mechanically and how to calulate the amps, torq, and voltage on this thing so I would now what size to of parts to use?

On the rest of this I would use basic metal working and basic sheet metal construction. Im not use to working with that kind of stuff but I would have to learn along way. Hopefully saving some money in the process.

Hey LloydB,

Armature lamination thickness is like .018 or .025 inch thick. Core length maybe 5 to 6 inch. Maybe 49 slots. That's like 12,000 little rectangles to cut out while holding dimensions to .001 inch tolerance

After all that, I doubt you'll be happy with the performance. Better save up the money and buy a motor.

Regards,

major

 

[major]

This was the exact question I was going to ask.
I know you said that performance would not be satisfactory but could you please elaborate on a suitable design? Or point me in the direction of some good web reading on the subject?

I wish to build an EV to trial out a battery system I have been scheming up, and wanted a cheap test subject to try it out on before I go ahead and spend the money on a more advanced system.

Kind Regards

Hi datahar,

I guess I don't understand. Would you go out and read a few web sites and step into an operating room and perform surgery? Ground up motor design is complex and requires a great deal of solid fundamentals and then more specific knowledge in the area of electromagnetics and energy conversion as well as machinery design and process techniques. But barring spending 4 to 6 years at university and 5 or so in the field, read the web and go for it.

Not trying to be rude here. But realistic. Cedric Lynch did similar to what you suggest and has Agni Motors to claim for it. Maybe it can be done again. By you? I don't know. But I bet chances are slim. You want to do an EV, buy a motor. You want to design motors, forget about the EV for many years.

Just my opinion.

major

ps....Most text on the subject of DC motor magnetic circuit design have been out of publication for 60 years or longer. I had to buy microfilm reprints of them back in the 1970's. Occasionally I see scanned versions of similar text on web sites for sale. They give you a few pages to view for free, but hide the bulk of it. Of course now-a-days, they have magnetic finite element analysis simulation programs. Learn how to use one of those. Good luck.

 

[major]

However, if you have the means to produce a motor well then you could start with this download.
http://greenev.zapto.org/electricvw/Electric_VW/PDF_Books.html
It is a book on electric motors.

Looks like a good general text on electric machinery. One which may have been studied at university. But does not begin to touch on specifics such a DC motor armature winding patterns or magnetic circuit geometry (slot and tooth dimensions).

 

[major]

Wish me luck. I have some equations to try to go over.

So LloydB,

What you're saying is you don't mind cutting out 12,000 little rectangles? Kool Bit of advice. Make a knotcher die. Cut out each rectangle with a single stroke exactly the right size.

Glad you realize the limits of human hand workmanship capability and are willing to buy bearings

Good luck Dude.

major