Cutting speeds

Hi,

I know this will sound like a really purile question and I'm really aiming
it at those who do small work on desktop machines but here goes...

How do you decide on an appropriate feedrate for materials and cutters you
haven't used before? For example, say you were presented with a piece of
titanium sheet and asked to cut out several identical parts using, say, a
dental burr - how would you decide on the best feedrate to use or, at least,
choose one that wouldn't break the tool or dull its cutting edges? I know if
I'm working on my manual lathes or miller that I can adjust the speeds and
feeds to get optimum performance simply by using my ears and the feel of the
handwheels but this isn't possible with a cnc machine as you have to program
in a feedrate and then just hope its Ok.

Wise words from the knowing would be greatly appreciated.

Ian
--
Ian W. Wright
Sheffield UK
www.iw63.freeserve.co.uk