On Mon, 16 Aug 2010 13:02:39 -0700, Tim Wescott wrote:
On 08/16/2010 12:07 PM, Karl Townsend wrote:
....
On Mon, 16 Aug 2010 10:38:00 -0500, Pete C. wrote:
Vice-Grips are not intended as machining clamps. Try the clamp bars
in the holdown kit, they are intended for the use and will give you
high clamping pressures when used properly.
....
The majority of parts you make will have workholding issues. This is
probably the number one thing that separates a good CAM programmer from
a terrible one. You have to know how to make a part before you automate
it.

I'm big on optional stop in my program for clamp moves. Often a clamp
can be moved while the machine runs. If you got it moved before it gets
there, flip optional stop off and machine keeps going. if you didn't
finish, machine stops and waits for you.

Does anyone make NC clamps to automate that operation?

I really wish I were being flippant here, but I have this horrible
suspicion that it's been done, and commercialized.

Some palletized parts loaders (IIRC Haas Quickcube) can present
parts at all angles. On dual pallet systems a person can be
changing part positions on one pallet while the system works with
parts on another pallet. I saw several pallet systems (sort of
like at http://www.youtube.com/watch?v=iG3L2uHqdE0) in use when
I toured a small-town factory making high-lift booms (like in
picture at http://www.terexutilities.com/) for Terex.

OT - In following video, part transfer is manual - a person
keeps walking around in a circle of 7-8 machines transferring
motor parts: http://www.youtube.com/watch?v=AUPji7L9aSs&NR=1

--
jiw