Go to the hardware store and get a 4- in. PVC coupling. It is double ended and has two rubber inserts, so it’s like getting 2 for one.
Take the cap off one end and it fit on your chuck. Cut in ½ – in. with a parting or detailing tool. This gets squares up the end.
Expand the opening in the cap some.
Use the screw-on end to place the ball, line it up, and screw the cap on. It tightens sufficiently to hold the ball securely.
Use a Jacob’s chuck in the tail stock and drill a pilot hole thru the ball. Use this to line up the bottom for the foot when you flip the ball, if you’re making one.
Drill a hole in top with a Forster bit in your desired width to begin hollowing.
Sand the outside up thru microfiber grits and inside to yout desired finish. I finished with coats of McGuires polish.
Turn the top, finial and foot as desired.