n = V
c
· 1000
π
· D
c/eff
f
z
=
V
f
n · z
V
f
= n · z · f
z
P =
a
e
· a
p
· V
f
18000
V
c
=
π
· D
c/eff
· n
1000
f
n
= z · f
z
f
n
=
V
f
n
T = I
f
V
f
Q = a
e
· a
p
· V
f
1000
n =
250
·
1000
= 2275 U/min
π
·
35
V
f
=
2275
·
3
·
0,6
= 4095 mm/min
Q =
(25
·
1,5
·
4095) = 154 cm
3
/min
1000
P =
(25
·
1
,
5
·
4095) = 8
,
5 kW
18000
FORMULAS AND
CALCULATION EXAMPLES
Formulas
Calculation Example
Definitions:
Calculation of revolutions of
main spindle in [min-1]:*
Calculation of feed per tooth in
[mm/tooth]:
Calculation of feed per min. in
[mm/min.]:
Calculation of power requirement
in [kW]:*
Calculation of cutting speed in [m/
min]:*
Calculation of machining time in
[min]:
Calculation of machining time in
[min]:
Calculation of chip volume in
[cm3/min]:
* Please note: For flat con-
tours use true mill diameter to
calculate cutting speed (see
Surface Finish section).
* Please note: The formula gi-
ven for calculating the power
requirement is valid for machi-
ning steel only.
width of cut [mm]
depth of cut in [mm]
cutter diameter in [mm]
true tool diameter in [mm]
feed per tooth in [mm]
milling length in [mm]
feed per revolution in [mm/U]
revolution in [rpm]
power requirement in [kW]
chip volume in [cm3/min]
machining time in [min]
cutting speed in [m/min]
feed per min. in [mm/min]
no. of effective teeth
35200
03 12 840K
(P40, PVTi coated)
Ø 12 x 3,97 mm
35 mm
3
1,5 mm
25 mm
1.1730, roughing
Vc = 250 m/min
fz = 0,6 mm
Milling cutter:
Selected insert:
(see Cutting Material p. 421)
Size of insert:
Milling cutter diam.:
no. of effective teeth:
Depth of cut:
(see Operation Data Table)
Width of cut:
Material to be machined:
Selected cutting speed:
(see Operation Data pp. 392, 393,
408)
Selected feed per tooth:
(see Operation Data pp. 394-401 +
410-417)
Calculation of revolutions
Calculation of feed per min.:
Calculation of chip volume:
Calculation of power requirement:
a
e
a
p
D
c
D
eff
f
z
l
f
f
n
n
P
Q
T
V
c
V
f
z
formulas for calculating the true mill diameter can be found in the Surface Finish selection.
215
Formulas and calculation examples
