ACU-RITE CNC 3500i - Manual (Page 54)

28 2 Machining Fundamentals
2.1 F
u
ndamentals of P
o
sitioning
Designation of the axes on milling machines
The X, Y and Z axes on your milling machine are also referred to as tool
axis, principal axis (1st axis) and minor axis (2nd axis). The assignment
of the tool axis is decisive for the assignment of the principal and
minor axes.
Polar coordinates
If the production drawing is dimensioned in Cartesian coordinates, you
also write the part program using Cartesian coordinates. For parts
containing circular arcs or angles it is often simpler to give the
dimensions in polar coordinates.
While the Cartesian coordinates X, Y and Z are three-dimensional and
can describe points in space, polar coordinates are two-dimensional
and describe points in a plane. Polar coordinates have their datum at a
circle center (CC), or pole. A position in a plane can be clearly defined
by the:
 Polar Radius, the distance from the circle center CC to the position,
and the:
 Polar Angle, the value of the angle between the reference axis and
the line that connects the circle center CC with the position.
Tool axis Principal axis Minor axis
X Y Z
Y Z X
Z X Y