There are collets that will take objects like billiard balls, i have dozens of them. But for a one-time app, not exactly cost effective.
The simplest way to do one, is to do it on a drill press. Get a short piece of plastic Shed.40 drain pipe, coupler, or other short ring.. I know 1-1/2" will work, not sure if 2" will be too big (don't have any 2" here to check at the moment). Like 1/2" or 1" tall, whatever keeps the ball center from touching table
If you are in a hurry, place the ball in the ring, center it up by eye, and start drilling. You will be able to tell by where the drill lips (not center) hit first as you start in. Adjust accordingly so the lip is hitting the same all the way around the beginning hole..
*better* if you have a DP vise, put the ring against the back jaw and snug the ball in with something soft to protect the front. Drill as before. The added mass of the vise will make it easier to control.
If you have a DP with enough daylight so the head or table would not need moved: Clamp a nice parallel surface piece of wood across the table. Drill it with a hole saw, say 1-3/4" dia, but smaller will work. Don't drill through (to avoid scaring DP table) But use a chisel to pop out enough wood that the CB sets down tight all around the perimenter. Now it is centered (so long as your board is parallel).
Change the holesaw for your desired bit, and have at it.
If you have a faceplate for the lathe, find a washer or ring such that the center hole that will clear your intended drill/tap size by a good bit. Press the CB into the center hole/register of the faceplate, put the ring over it, and with your 3rd hand :thumbup: put some clamp bolts in the FP slots to hold the ring in place, retaining the CB sandwiched to the faceplate, automatically centered in the FP center hole.
Again on the lathe, if you have a big enougn chuck (tall enough jaws) obviously use that. If the chuck jaws are not tall enough and it takes top jaws (2 pc jaws) you can bore a tall set of soft jaws as necessary, using the lathe tools.
If this is production & your lathe takes 5c collets, you can get a deep series 2" or 3" with closer ($$$$) and bore it to take the CB. You can find these on eBay and often cheap at machine shop auctions. Just not when you need one this week....
Attached pic is what the 5c deep series step collet ("emergency collet") and closer would look like (top left) the rest of the stuff is using shop made inserts in the bored collet for other projects. Sorry, this is the only photo i have that is fast for me to find. Hardinge sells the collets and the closers if you are in a hurry.
smt