Here’s my own short demonstration of the “magneto-electric train.” It is surprisingly easy and cheap to put together. I used a AAA battery as the power source, and a pair of strong neodymium magnets I had on hand; to give the train more “oomph,” additional magnets could be used on either side of the battery. I used 18 gauge copper wire for the coil, and wrapped it around a 1/2” ring stand to coil it. It is important that the wire be uncoated — otherwise current will not flow and nothing will happen! The 18 gauge wire seemed like the right balance of being easy to bend but rigid enough to hold a shape. Also, it was all I could find at short notice.