James Smith posted an "upgrade" to his dubbing block on old Fly Fisherman BB when it was on outdoorsbest.forum.com

I hope James won't mind me quoting him. He wrote, ""I came up with a very simple idea to add power to these dubbing brush twisters if you have a Dremel, electric drill or battery powered drill. I simply inserted a stainless steel set screw into the twisting knob. You can then put an Allen/Hex wrench into your Dremel or Drill, insert it into the set screw, and you're in business. I tried these out and it works great, REALLY speeding up the twisting process."

Another variation was by "Ducksterman" using flexible vinyl tubing to connect a motor to James Smith's dubbing brush wheel. His photos are below.