I originally posted this at another site. Maybe some here will find it usefull.
It's how I machined the bottom radius of the crankcase for my build of Gail Graham's Lobo Pup Twin.
It should be noted that the bulk of material was removed in the mill prior to this operation. This is more of a finishing op.
The Dremel FexShaft is held in a tool block that was bored on center with the lathe.
This is the YouTube description-
"This video shows a crankcase being machined on the lathe with a Dremel Flex Shaft. The crankcase is on an arbor and is being indexed by hand. The 1/8 endmill is set on center and is cutting on the tangent point of the radius. This was an experiment that worked out far better then I had hoped."
-Bob