Hopefully this will help ya. But,...This is certainly NOT the only way you can turn a pot.
Just the way I do it.
1st) Find center in your blank. I use a forsner bit to make the center of my pedestal.
Then trim off the corners. Use this chuck, and by expanding, hold the pot. Do the
Outside of your pot first.
2nd) Find an old motorcycle inner tube. Make a wide rubber band, and use it to protect
your pot from the jaws of the next chuck.
Change out your chuck, and hold your pot from the outside, and turn the inside.