Re: [CAD_CAM_EDM_DRO] CNC on a lathe

Chris and Dee wrote:

>Another question for everybody. And for this question I need to
>clarify that I'm NOT a machining wiz - in fact I don't even have my
>own lathe yet.
>
>If a lathe is converted to CNC, I thought that it would make
>machining complex tapers and rounds or spheres much easier. But as I
>looked at the current manual devices that cut these shapes - say the
>spherical ends - the cutter rotates with the device. Which seems to
>make sense because then your cutters' angles are always 'correct' in
>respect to the tangency of your cut surface.
>
>For a CNC lathe, how do you go about cutting a spherical end without
>changing tool bits?
>
>If this is a stupid question, I do apologize.
>
>

You use a circular cutting tool. There is an indexable carbide insert
that is round. You can't
cut a complete sphere, as there would be nothing left to hold the part
on the chuck. But, if you have
a tool holder that will expose slightly more than 180 degrees of the
round insert, you can
do all the external sphere work you could want. Boring most of an
internal sphere
would require a holder with a "hook" on the end.

Jon