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.

wrote in message
...
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.

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

On 10/24/2012 5:50 PM, wrote:
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 assume you know about these type countersinks:

http://www.2linc.com/countersink_depth_stop.htm

One brand is Severance and are called Micro-stop countersinks.

--


___________________________________

Keep the whole world singing . . .
Dan G
remove the seven

On 2012-11-13, DanG wrote:
On 10/24/2012 5:50 PM, wrote:
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 assume you know about these type countersinks:

http://www.2linc.com/countersink_depth_stop.htm

One brand is Severance and are called Micro-stop countersinks.

It would work with springy workpieces which need to be clamped
down to a stable level support (the "slightly bowed" ones), but not for
variations in thickness -- unless the CNC machine is also fitted with a
spring-loaded shank. I've got a couple of the Severance ones in
drill-press size, and like them for constant depth, but I don't think
that they would work well in what is described as the problem.

Hmm ... maybe this has the spring give in the shank, and thus
might well do the job. Those springs look serious.

Good Luck,
DoN.

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