Chapter 2 - page 21
MCO-TCO work mode
2.6.2.1 OPERATING AT CONSTANT SURFACE SPEED (CSS)
When Constant Surface Speed operating mode is selected (CSS), the CNC assumes the spindle range
selected at present.
In this operating mode, when a new constant surface speed is selected, the following cases may arise:
a)
The spindle is stopped
The CNC selects the new speed but does not apply this until the spindle moves.
b)
The spindle is started
The CNC, depending on the position of the axis, calculates and makes the spindle turn at the
corresponding rpm. speed for the Constant Surface Speed to be as defined.
As the axes move, when working at Constant Surface Speed, the following cases may arise:
a)
The spindle is started
The CNC moves the axes to the F programmed.
As the X axis is moved, the CNC makes the spindle speed (rpm.) match to maintain the constant
surface speed selected.
If the tool tip moves away from the turning axis the spindle revolutions therefore go down, and
if it gets nearer, they go up.
The CNC limits the spindle revolutions to the maximum speed set «SMAX».
b)
The spindle is stopped but a spindle speed S is selected
The CNC calculates, in millimeters/minute, the feedrate corresponding to the last programmed
"S" and moves the axis.
For example, if «F 2.000» and «CSS 500»:
F (mm/min) = F (mm/min.) x S (rev/min) = 2 x 500 = 1000 mm/min
The axis moves at a feedrate of 1000 millimeters/minute
c)
The spindle is stationary and there is no spindle speed S selected.
The axes will only move in rapid and only if
and the relevant axis key are pressed.
