Siemens SINUMERIK 840D SL Operating Manual page 249

Feedrate (F)
The feedrate F (also referred to as the machining feedrate) specifies the speed at which the
tool moves when machining the workpiece. The machining feedrate is entered in mm/min,
mm/rev or in mm/tooth. The feedrate for milling cycles is automatically converted when
switching from mm/min to mm/rev and vice versa.
It is only possible to enter the feedrate in mm/tooth during milling; this ensures that each
cutting edge of the milling cutter is cutting under the best possible conditions. The feedrate
per tooth corresponds to the linear path traversed by the milling cutter when a tooth is
engaged.
With milling cycles, the feedrate for rough cutting is relative to the milling tool center point.
This also applies to finish cutting, with the exception of concave curves where the feedrate is
relative to the contact point between the tool and workpiece.
The maximum feedrate is determined via machine data.
Converting the feedrate (F) for drilling and milling
The feedrate entered for drilling cycles is automatically converted when switching from
mm/min to mm/rev and vice versa using the selected tool diameter.
The feedrate entered for milling cycles is automatically converted when switching from mm/Z
to mm/min and vice versa using the selected tool diameter.
Spindle speed (S) / cutting rate (V)
You have the option of either programming the spindle speed (S) or the cutting rate (V). You
can toggle between them using the <SELECT> key.
In the milling cycles, the spindle speed is automatically converted to the cutting rate and vice
versa.
● Spindle speed and cutting rate remain valid until you program a new tool.
● Spindle speeds are programmed in rev/min.
● Cutting rates are programmed in m/min
● You can set the direction of rotation of a tool in the tool list.
Converting the spindle speed (S) / cutting rate (V) when milling.
Milling
Operating Manual, 02/2012, 6FC5398-7CP40-3BA0
Radius compensation to right of contour
Radius compensation to left of contour
Radius compensation off
Radius compensation remains as previously set
7.7 Tool, offset value, feed and spindle speed (T, D, F, S, V)
Creating a ShopMill program
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