TABLE OF CONTENTS Normally, a programmed tool motion for a CNC machining center represents the dimensions of the drawing, perhaps with cutter radius offset in effect. Occasionally, there may be times when the machining tool path that has already been programmed once must be repeated, but machined as smaller or larger than the original, yet still keep it proportional at the same time. To achieve this goal, a control feature called the Scaling Function is used. Note the following two important items:
Scaling function is an option on many controls and may not be available on every machine
Some system parameters may be used for this function as well
For even greater flexibility in programming, the scaling function can be used together with other programming functions, namely with Datum Shift, Mirror Image and Coordinate System Rotation - subjects described in the last three chapters.
The control system applies a specified scaling factor to all programmed motions, which means the programmed value of all axes will change. Scaling process is nothing more than multiplying the programmed axis value by the scaling factor, based on a scaling center point. The programmer must supply both the scaling center and the scaling factor. Through a control system parameter, scaling can be made effective or ineffective for each of the three main axes, but not for any additional axes. The majority of scaling is applied to the X and Y axes only.
It is important to realize that certain...
