Dime and or Nickel radius powered shaper

[DaveK]

I think this is close to what you are talking about. I have used it for years and it works great.
http://www.porper.com/index.cfm/fus...f6515eef2-CB9F2289-20ED-7D0A-C05E1B4B2CC41D3A

Yes, that's the same type of radius cutter / ball cutter.

Sherline sells theirs for $120 :

http://www.sherline.com/2200pg.htm

The Taig is way less money at $20.10 !

http://www.taigtools.com/c1210.html

They are also easy to build, which is why it's a common DIY project for small lathe owners.

Dave