Guy by the name of Brad came up with this little adapter to convert the a Regal vise into true rotary.
He got into quite a battle with the maker of the Regal that there was talk of lawsuits!
And, the Regal company said using it would negate the warranty.
Brad finally came up with his own "Concorde" vise , similar to, but different from the Regal.
The "Concorde" Vise
It comes with an aluminum weighted base which is somewhere I can't find right now.