Re: [CAD_CAM_EDM_DRO] Coordinate Measuring Machine

On Sun, 04 Dec 2011 07:31:36 +0100, you wrote:

>Almost all probe designs I have seen are not, in my mind, adquate.
>Basically, because their premise is that creating a "touch" is
>sufficient without any regard to the plane, direction, etc of the contact.
>Thus they make a point cloud in a fairly repeatable, but by no means
>accurate manner.

ALL the CMM machines I've seen use Renishaw type probes. So in everybody
else's mind they are perfectly adequate.

The probe is touched off and calibrated against a home device (often a
sphere of known dimensions) and then the measurements take place.
Repeatability is excellent.

That type of probe design is easy to make, the patent has expired and
was never enforceable anyway, as the idea was prior use.

Steve Blackmore
--