Jack, last summer I made two tops out of small, plastic water bottles. One was filled with sand, and the other with clay kitty litter. Both tops have large acorn nuts, like those you have, as "tips".
I took them with me to Miamisburg, and several attendees spun them in the parking lot. They actually spin quite well! They don't work too well for tricks, although someone (Mark Hayward?) managed to boomerang one of them....