Fagor DDS Series Hardware Manual page 207

For lathe work, a cutting blade forces against the part to be machined, while
this is turning. See figure F. H5/3
The power required, Pc is calculated as follows:
L
D
F. H5/3
Machining for lathe. Cutting power.
V Cutting speed in m/min
K Relative cutting resistance in N/mm²
s
d Cutting depth in mm
L Length of the blade, or feedrate per full turn in mm
D Diameter of the part machined in mm
N Spindle turning speed in rpm
s

Mechanical efficiency (varies from 0.7 to 0.85)
c
Cutting efficiency. Cutting volume per kilowatt every minute
S
c
in (cm³/kW)/min
In the case of a milling machine, the cutter is mounted on the spindle itself
and turns with this to cut the material. See figure F. H5/4
The power required, Pf is calculated as follows:
f
F. H5/4
Machining for mill. Cutting power.
K
Relative cutting resistance in N/mm²
s
d
Cutting depth in mm
W
Cutting width in mm
f
Feedrate in mm/min
N
Spindle turning speed in rpm
s

Mechanical efficiency (varies from 0.7 to 0.8)
f
Cutting efficiency. Cutting volume per kilowatt every minute
S
f
(cm³/kW)/min
.
d
·d·N
s
(m/min)
V =
1000
K ·d·L·v
s
P = =
c
60·1000·
c
.
f
K ·d·W·f d·W·f
s
=
P =
f
60·1000²· 1000²·S
f
  Selection criteria
5.
d·L·v
(kW)
S ·
c c
(kW)
·
f f
HARDWARE
Ref.1912
DDS
· 207 ·