Re: Up and Down; Is Z- away from the part or into the part?

--- In CAD_CAM_EDM_DRO@y..., "Daniel J. Statman" <dan.statman@r...>
wrote:

> I do not know what a commercial machine does, but I have found that

it does

> not matter at all

Do not listen to Dan, you will hurt yourself!


All axes are defined by the RS-274G. Those identified in the NIST
274 documents are accurate. You can find it at the EMC site.

Machine zero for the Z axis is up(safe position). All tool motion
toward the table is negative as far as the machine coordinates are
concerned. All programming should be relative to tool movement,
whether the tool actually is moving or the table. This is identical
to the layout of the cartesian coordinate system in which the upper
right quadrant is + in X and + in Y, and the lower left quadrant is
minus in X and minus in Y. Therefore anything you draw in Autocad,
Intellicad, Vector, Bobcad, Turbocad, or whatever Cad system will cut
correctly in X and Y.

You can reset your zero points to any position within the volume of
your machine travels. For example if you position the tool over the
lower left corner of the table and set X and Y to be zero (with a G92
for example), ALL additional motion will have to be programmed as
positive values in X and Y.


For safety, and especially if you are new at it, program your mill
from the top of material and your lathe from the face of the part.
You will then know that ANY minus value is cutting or crashing, so be
alert. "Program your Mill" means that your tool , with the offset in
effect will just touch the top of the part when Z=0, as in

N001 G01 Z0.0

Best Regards,

Fred Smith
IMService We are THE source for low cost Cad-Cam