Buckfevr,
I left the foam ball about 1/2" tall at the center and cut the groove so that there was about 1/8" of foam left for the arrow to ride on. My digital cam is Kaput right now so.......Get one of those foam balls, a knife, some scissors and some super glue and you'll come up with something.......It's by far the best I've found, and I tried everything I've ever seen or read on the internet or in magazines.

"What we do in this life echos an eternity"