How do i get my Rail Gun (AlexTheGreat's design) To fire?

I have everything the same as him except my rails are slightly bigger. The distance between them is 1.6mm, and im using aluminum wads. When i fire it, i see a large spark with a bang and sparks go out the rails but the aluminum stays in place! The only problem with this is that its just staying in place, its not welding itself.

I had the same problem with his coil gun. I was merely connecting the two leads instead of using a relay to complete the circuit. If you are just creating a spark at the joint, it probably is your problem. Try PMing him.