On Wed, 24 Oct 2012 18:22:44 -0700, Bob La Londe wrote:

wrote in message
news:1dc7f24a-ef69-4599-
...
I am looking at making many 1.5" holes with a countersink 1/2" deep in
large steel plate. The depth tolerance of the countersink is critical.
The plate varies in thickness and can be slightly bowed. How do I
control the depth of the countersink on a CNC machine? I can't just go
to the same Z position every time. The plate is too big to probe every
location and correct for depth, or at least I don't want to take the
time to do it. I found a spring loaded tool on the web but it is too
small.

Any ideas or tools I don't know about????

Thanks in advance. Any constructive replies are appreciated.


I guess it really depends on what your expertise level is and the
flexibility of the machine.

1. Make your own spring loaded tool.
2. Add a probe of some type next to the countersink, and do each
countersink as a probing operation. (Microswitch on a stick?) 3. Do a
probing operation first as a complete program for the whole plate at
each hole location.

I'm not a CNC guy, but for 1 & 2, make sure you're not riding on a chip,
and for 3, make sure that the bows & ripples of the plate don't change
from the time you probe to the time you countersink.

--
My liberal friends think I'm a conservative kook.
My conservative friends think I'm a liberal kook.
Why am I not happy that they have found common ground?

Tim Wescott, Communications, Control, Circuits & Software
http://www.wescottdesign.com