Siemens SINUMERIK 840D sl Turning Operating Manual page 305

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.
For milling and turning cycles, the feedrate during roughing is relative to the milling or cutting
center point. This is also applies to finishing, with the exception of contours with inner curves.
In this case, the feedrate is relative to the contact point between the tool and the 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)
The spindle speed S specifies the number of spindle revolutions per minute (rpm) and is
programmed along with a tool. The speed specified relates to the main spindle (S1) or counter-
spindle (S3) when turning and axial drilling, and to the tool spindle (S2) when drilling and milling.
The spindle starts immediately after the tool change. The spindle stops upon reset, program
end, or a tool change. The spindle's direction of rotation is specified in the tool list for each tool.
Cutting rate (V)
The cutting rate V is a circumferential velocity (m/min) and is programmed together with a tool,
as an alternative to the spindle speed. The cutting rate is relative to the main spindle (V1) or the
counter-spindle (V3) for turning and axial drilling, and corresponds to the circumferential
velocity of the workpiece at the point that is currently being machined.
However, for drilling and milling, the cutting rate is relative to the tool spindle (V2) and
corresponds to the peripheral speed at which the cutting edge of the tool machines the
workpiece.
Converting the spindle speed (S) / cutting rate (V) when milling
As an alternative to the cutting rate, you can also program the spindle speed.
For the milling cycles, the cutting rate (m/min) that is entered is automatically converted into the
spindle speed (rpm) using the tool diameter - and vice versa.
Turning
Operating Manual, 06/2019, A5E44903486B AB
9.8 Tool, offset value, feedrate and spindle speed (T, D, F, S, V)
Machine manufacturer
Please refer to the machine manufacturer's specifications.
Creating a ShopTurn program
305