Because it is DC I can use a permanent magnet core as Cody did.
I want to wrap it in some MU metal to help concentrate the magnetic fields too.
I do not mind if there is a repulsion force after the initial blast of attraction from the capacitor.
To reduce eddy losses I need the thinnest wire possible - but worried about it melting from heat...
I understand more turns increases magnetic force, however if I wind backwards down the shaft, & then up again in multiple layers would this have counteractive effects?
A low resistance wire is good eg copper, iron would carry more magnetic force how ever has higher resistance, copper is diamagnetic so creates an opposing magnetic force, alumium is paramagnetic, good conductivity (heck it's even used in some permanent magnets), though I've heard it can heat up quickly - reaching it's currie point & being blasted away with great force, if it was semi moulten that would not be good.
I've some smaller capacitors that I will start off with, not even sure if my microwave cap is functional.