Wuhan Huazhong Numerical Control Co., Ltd HNC-18iT, Programming Manual

Page: 18 / 145

1. General
14
1.5 1.5 1.5 1.5 Spindle Spindle Spindle Spindle Speed Speed Speed Speed Function Function Function Function
The cutting speed (v) refers to the speed of the tool with respect to the workpiece when the
workpiece is cut. The unit of the cutting speed is m/min. As for the CNC, the cutting speed
can be specified by the spindle speed (N) in min
-1
.
N
·
min
-1
Chuck
V: Cutting speed
v m/min
Figure 1.18 Cutting Speed and Spindle Speed
The formula to get the spindle speed is:
D
v
N
π
∗
=
1000
N: the spindle speed
v: cutting speed
D: diameter value of the workpiece
Example: When the diameter of workpiece is 200mm, and the cutting speed is 300m/min,
then the spindle speed:
m r
D
v
N / 478
200
300 1000 1000
≈
∗
∗
=
∗
=
π π
The constant surface speed refers to the cutting speed even when the workpiece diameter is
changed, and the CNC changes the spindle speed.