Speaking of tangents, etc....

Group,

One of my customers has a high speed 5 axis vertical machining
center, X,Y,Z plus rotate and tilt of the vertical head. They make
high-end musical instrument parts.

The usual cutter is a full radius ball end type which causes problems
on certain contours where the actual point of cut is near the tip of
the cutter. At the tip the peripheral speed is near zero, meaning
the feedrate has to be so slow that it's unproductive. That's where
the two extra head motions come in. The cutter can be oriented so
it's never normal to the contour being cut.

One of their big problems was how to instruct the machine to
correctly orient the head. They use the latest and greatest from
Mastercam which apparently wouldn't do the job. Last I heard, they
were hiring a Mastercam expert to develop a post processor to handle
the head movement. The cost of the post was estimated to be
$15K!!!! Fairly complicated stuff.

Doug