So I made a diagram, will this work?
Not as drawn. The positives go to one pole of the Spdt switch, the negatives to the other but the copper bar (Electromagnet? has nothing connected to the other end. Take the negatives to the other end of the wire around the bar,and then it should work. You only need the one end of the switch connected to the positive, and the center connected to the bar. If you leave the connectors on the batteries, they will drain into each other even with the switch off. This circuit has the potential of a lot of current, depending on the batteries, so be careful it could get dangerously hot. Forget the conductive tape.
