I don't personally own one but have seen dozens of posts regarding it on pen turning forums.
The first thing I would notice is that the piece being turned is mounted on a mandrel which means it would have to be hollow. I'm sure one could machine a clamping system to hold the columns somehow.
Secondly, the fact that a Dremel is used, I wonder what the lateral forces on the Dremel would amount to. I suppose with some good carbide ball mills and a really slow feed rate, one might pull it off. Also, I think the depth of cut is set manually by how you set the Dremel and the bit in the collet.
Third, since it is designed to cut wood I wonder if the stiffness of the Beall's frame and shafts would be adequate for metal.
I have seen some pretty intricate designs made on wooden pens. I have something similar that was sold by Sears that you could mount a full sized router to for fluting and spiral cutting wood rounds up to 3" dia. and 24" long. The Beall machine really is pretty small. Good news is that it didn't cost anywhere near $300. Bad news is that I don't see them listed on the Sears site. At least I couldn't find it in the 10 minutes that I looked.
I would be curious as to how difficult it would be for one of you guys with the "cool tools" to beef up the basic design of the Beall w/ some heftier steel drill rod and commercial gears with a micro adjustable mount for, say a 1HP trim router? Since I'm just a wanna be at this point, I'd love to hear what others have to say. Very nice concept. I likes it!
Ed