Re: [CAD_CAM_EDM_DRO] linear, circular, and helical interpolation?

cdoughty@... wrote:

> Hi All,
> Can anyone explain what linear, circular, and helical interpolation
> means and why one should have it?

Linear interpolation means the machine will move in a straight line from the
start point to end point, at any angle required. Without linear interpolation (on
some CNC controls) the two axes will move in an uncoordinated fashion, with
the axis that needs to make a shorter move getting there first. This will cause
a move that has a 'dog leg' in some part of the movement.

Circular interpolation means that the machine will move in a circular motion,
for some part of, or an entire circle. This is very useful for boring a large round
hole in a part with a smaller diameter end mill.

Helical interpolation means that two specified axes of a machine will move in
a circular motion, and a 3rd axis will move in a linear motion, with all 3 axes
arriving at the end point at the same instant. This can be used with a variety of
thread milling tools to mill a thread of arbitrary size, without needing to have
a tap for that size hole.

Jon