Don Foreman wrote:
...
Focus on keeping the current to a level that won't burn out the
winding. Don't worry about saturation in a DC electromagnet. Having
it saturate is not a problem. ...

I have kinda' backed into that conclusion - given that it's not
saturated when it's outputting 2000v, and seeing the heating that I'm
getting so far (120v).

It's a bit surprising that, for given core cross section and winding
window area, the max flux possible with a copper winding is
independent of wire size. Voltage and current change, of course, but
Bmax doesn't for given current density in the copper.

It makes sense from the fact that flux is a function of amp-turns. 1
amp through 100 turns or 100 amps through 1 turn. In my MOT
electromagnet it's a lot easier to put higher voltage & less current
through 2000 or so turns of secondary than small voltage & large current
through 120 turns of primary.

The attraction force you get will be B^2*A / 2*muzero where B is flux
density, A is area, muzero is 4*pi*10E-7 newton/amp^2. Flux density
will depend on the total magnetic circuit including whatever is being
attracted.

I suppose before I had started my experiments I could have used that to
calculate force. I would still have verified it, but it would have
given me a better idea of where to start.

Thanks,
Bob