Wrap the aluminum skin on the cone frame and attach with small picture hanging nails. Glue the inside of the skin to the frame with Goop. Place Goop around the outer skin at the cone rim to glue it to the rim. After the Goop has dried, remove the nails in the skin. Magnets must be clamped to prevent movement of the magnets.
All magnets have the same side facing out.
Will explain Magnetic layout later. Create 2 more cones the same way, except the top cone. The Top cone rim should be solid 4 diameter. After all cones are assembled, file the tips to a very sharp point of 30degrees exactly at the cross section of the cone angle. Cone height will be 4 from point to rim.