Cutting Rate (Svc) - Siemens SINUMERIK 840D sl Programming Manual

6.2

Cutting rate (SVC)

Function
As an alternative to the spindle speed, the tool cutting rate, which is more commonly used in
practice, can be programmed for milling operations.
The control uses the radius of the active tool to calculate the effective spindle speed from
the programmed tool cutting rate:
S = (SVC * 1000) / (R
where:
The tool type ($TC_DP1) of the active tool is not taken into account.
The programmed cutting rate is independent of the path feedrate F and G function group 15.
The direction of rotation and the spindle start are programmed using M3 and M4 respectively
and the spindle stop using M5.
A change to the tool radius data in the offset memory will be applied the next time a tool offset
is selected or the next time the active offset data is updated.
Changing the tool or selecting/deselecting a tool offset data record generates a recalculation
of the effective spindle speed.
Conditions
The programming of the cutting speed requires:
• The geometric ratios of a rotating tool (milling cutter or drilling tool)
• An active tool offset data record
Fundamentals
Programming Manual, 09/2011, 6FC5398-1BP40-2BA0
* 2π)
T
S: Spindle speed in rpm
SVC: Cutting rate in m/min or feet/min
R : Radius of the active tool in mm
T
Spindle motion
6.2 Cutting rate (SVC)
93