"George" George@least writes:
Or a NOVA, which has a taper capable of being used as a bumper on
its own which is also threaded for homebrew attachments like inside
steady cones, jam chucks and such.

Even my Grizzly center has a pop-out point, so you can turn a wooden
taper to fit it.

Or gee, just turn a stick with a hole on one end, and use the center's
regular point to hold it in place.