OVERVIEW

Helical milling uses an optional control system feature called helical interpolation. In its simplest definition, helical interpolation is an operation where a circular interpolation uses three axes simultaneously. This could be a misleading statement because it implies a three dimensional arc or a circle. Such an arc or circle does not exist anywhere in the field of mathematics. Yet, it is true that the G02 or G03 circular interpolation command does use all three axes - for example,

G03 X.. Y.. Z .. .. F..

This type of operation is only available for CNC machining centers as an optional feature. Let's look at the subject of helical milling a little closer.

HELICAL MILLING OPERATION

What exactly is helical milling? Essentially, it is a form of a circular interpolation - it is a programming technique to machine arcs and circles combined with a linear interpolation in the same block, during the same motion.

Previous topics that were related to circular interpolation presented one major feature of that subject. In circular interpolation, there are two primary axes used within the selected plane, with the intent to program an arc motion or a circular motion.

For example, in the G17 XY plane (the plane that is most common), a typical format of the circular interpolation will be in two forms:

Using arc centers IJK for CW and CCW motion:

G02 X.. Y.. I.. J.. F..G03 X.. Y.. I.. J.. F..

Using radius R for CW and CCW...