The
First, roll one
Roll the second paper
Glue the paper cylinder to the plate; try to glue it exactly at the center of the plate..
Start making the coil, keep the magnet inside so you don't crush the paper cylinder..
Fold the business cards as the picture shows..
If the magnet is not high, try to make small three tight fold.
Glue the cards to the foam plate. Try to align both business cards. (Parallel)
Now, put the plate so the business cards and the magnet stick to the base. The "base" can be a solid cardboard or wood. Anything flat and rigid works fine. I did use a cardboard. Using wood, the sound is better as wood vibrates less than cardboard.