smiller@wet.UUCP (Gregory Shane Miller) (06/16/91)
I'm interested in getting sources for laser light based units which measure
distance. I have two specific applications in mind:
[1] We have a 3 AXIS CNC machine and would like to use a laser light
beam to measure the distance from the head (Z axis) to the object
being machined (in our case a piece of FR4 copper clad).
[2] In the production of the CNC machines, I would like to have two
of these units mounted at right angles to one another with their
beams pointing at the CNC machine. Then as part of the quality
control, I could move the machine through a standard test, and
then by using the light beams as a second measuring system, I could
find and correct problems like:
[a] stepper/servo motors missing steps. This is really great
for stepper motors.
[b] non-perpendicularity in the X,Y axis
[c] if the X,Y axis is slightly bowed or "snakes".
I'm looking for a system in which can do accurate measurements down in the
.0000x range. Does such a laser/optical test system exist? Is there an easier
method to accomplish the same thing? Thank you for any replies.
(smiller@wet.UUCP).
BTW - this technique has a couple of pratical disadvantages when it comes
to setup. In [2], how should one position the laser beams at exact
right angles (perhaps an interference test could be made). Second,
even if you could, how should one place the test object such that it
is not rotated somewhat with respect to the laser beams? Can enough
of the laser beam even bounce off a CNC machine or FR4 copper clad
and return to the optical measuring unit?
--
G. Shane Miller [ smiller@wet.UUCP (415) 453-4926 ]