I use a much older version of this1/2 inch shaper arbor
I have 2, one for each side. I do quite a bit of buffing between pen making and hand tool refurb.
I have also used 1/2 inch coarse thread bolts 2 washers and a nut. Hold it with the drill chuck.
For the pen making, I'm building a 3 wheel buff for use in lathe mode using 1/2 inch all thread, 2 nuts and washer per buffing wheel and some 1/2 inch PVC spacers between the wheels.
Drill a tapered hole in one end of the rod using a 60 degree starter bit to seat on a 60 degree live center in the tail stock.
Rod is held with my 1/2 inch collett chuck at the head, the drill chuck could also be used (If I could find mine, it's still MIA. I'm sure as soon as I purchase a replacement it will turn up.)
I may build a 2 wheel model of this for my metal buffing wheels.