HEIDENHAIN TNC 640, User Manual, Page: 217 / 948

Programming Aids | Cutting data calculator
5
HEIDENHAIN | TNC 640 | Conversational Programming User's Manual | 10/2017
217
5.6 Cutting data calculator
Application
With the cutting data calculator you can calculate the spindle speed
and the feed rate for a machining process. Then you can load the
calculated values into an opened feed rate or spindle speed dialog
box in the NC program.
You cannot perform any cutting data calculation in
turning mode with the cutting data calculator because
the feed rate and spindle speed data are different in
turning mode from milling mode.
Feed rates in turning operations are often defined in
millimeters per revolution (mm/1) (
M136
), whereas the
cutting data calculator always calculates feed rates in
millimeters per minute (mm/min). Furthermore, the
radius in the cutting data calculator is referenced to the
tool; turning operations, however, require the workpiece
diameter.
To open the cutting data calculator, press the
CUTTING DATA CALCULATOR
soft key. The control shows the soft
key if you
open the on-line calculator (press the
CALC
soft key)
open the dialog field for spindle speed input in the TOOL CALL
block
open the dialog field for feed rate input in positioning blocks or
cycles
enter a feed rate in manual mode (press the
F
soft key)
enter a spindle speed in manual mode (press the
S
soft key)
The cutting data calculator is displayed with different input fields
depending on whether you calculate a spindle speed or a feed rate:
Window for spindle speed calculation:
Code letter Meaning
R: Tool radius (mm)
VC: Cutting speed (m/min)
S= Result for spindle speed (rev/min)