Acu-Rite CNC 3500i user manual Designation of the axes on milling machines, Polar coordinates

2.1 Fundamentals of Positioning

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.

Tool axis	Principal axis	Minor axis
X	Y	Z
Y	Z	X
Z	X	Y

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.

28 2 Machining Fundamentals