ACU-RITE MILLPWR 2 Axes - Manual (Page 25)

DRO
MILLPWR ®
Operation Manual 2-8
Establishing Datum
Datum, also known as workpiece zero or absolute zero, is the point of reference that
MILLPWR bases all of the part's coordinates from.
It is necessary to establish datum for every job. Datum's location may be indicated on a
print; if it's not, establish a datum that enables most of the part's dimensions to be entered
directly, with the least amount of calculations.
When establishing datum, you may find it easiest to locate a known point on each axis, such
as the edge of the part or a location on the vise or fixture.
Refer to the procedure below as a basic guide for establishing datum. Decide to "touch off"
using an electronic edge finder, a mechanical edge finder or a tool. Datum may be set at a
point on the top surface or a position above or beneath the surface. X and Y datum may be
set on an edge, or offset into or off of an edge, or where there's no material present (such as
in the center of a circular part). There are many possibilities-- do what’s easiest for a partic-
ular job.
MILLPWR will retain datum even after the system has been powered down.
(See Finding Home).
Define datum one axis at a time. Begin here with the X-axis:
• From the DRO screen, press the DATUM softkey.
• Insert the proper tool into the spindle.
To establish datum:
Where and how datum is establish will vary from
job to job. One of the most common methods of
establishing datum is described below. Apply the
same principles when setting datum for future jobs,
making adjustments to the procedure as needed.
The following example will establish datum at the
corner where the left, front and top surfaces of the
part intersect. This is accomplished by "touching"
each face with the tool used to cut the part.