Owner's manual

Introduction to Programming

Chapter 10

10-39

Cutting Speed

The term “cutting speed”refers to the velocity of the surface of the

revolving cutting tool relative to the workpiece. Cutting speeds are

determined by the spindle speed in revolutions per minute (rpm) and the

diameter of the cutting tool in the following equation:

Metric Units English Units

3.14159xDxN 3.14159xDxN

V = --------------- V = -----------------

1000 12

Where : Is :

cuttingspeed in metersorfeetperminute

diameterof the toolin millimeters orinches

rpmofthe spindle

Or, stating t he equations in terms of required spindle rpm:

Metric Units English Units

N = 318.30989 --- N = 3.81972 ---

From the metric equation, if a desired cutting speed is known, for example

V = 100 surface meters per minute using a cutting tool with a diameter, D

= 100 millimeters, the spindle speed, N is equal to approximately 318 rpm.

Spindle speed is programmed with an S--word. In this above example the

S--word would be S318.