Re: [CAD_CAM_EDM_DRO] Magnets.....OT?

Hi Ray,

I have the magnets out and was going to make a tube so they could be slipped
inside one at a time with the North/South being checked with a compass.

I can buy enamelled copper wire in most sizes and I have a large 12 volt 10
amp transformer with a big enough bridge to do the job. I also have many
smaller transformers around the 2 amp mark. I don't understand the "500
circular mils"? And I'm a bit thick where ohms law is concerned. Could you
lead me by the hand on this?

Regards,

Terry

> First off, I wouldn't use a car battery, I'd use a doorbell transformer

(or

> something about 12V at a couple of amps) and a 4-diode full wave bridge.
> The pulsating DC will give you better magnetizing that straight DC. Number
> of turns? As many as possible, depends on what wire size you use. You'll
> have to size the wire to carry the current you can generate. We used to

use

> about 500 circular mils of wire size per amp of current. That's just a
> starting point. Also, your chuck is made from interleaved north & south
> poles (at least mine is). You'd make a U-shaped pole that would just span
> one north-south pitch, magnetize there, then rotate just one pole to the
> other side, magnetize there, and sort-of 'walk' the electromagnet down the
> chuck, pausing at each step to do the magnetize thing (I dunno if you have
> to leave the chuck handle engaged, or not). This will keep the proper N-S
> orientation. Catch me off-list when you have more info, and I'll help if I
> can.
>
> RayHex