2 - Fagor Automation

Selection criteria
5.
SELECTING CRITERIA
Asynchronous spindle motor and servo drive selection
232
DDS
HARDWARE
Ref.1209
212
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:
F. H5/3
Machining for lathe. Cutting power.
V Cutting speed in m/min
Ks Relative cutting resistance in N/mm²
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 s
c
S c
Spindle turning speed in rpm
Mechanical efficiency (varies from 0.7 to 0.85)
Cutting efficiency. Cutting volume per kilowatt every minute
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. H5/4
Machining for mill. Cutting power.
Ks Relative cutting resistance in N/mm²
d Cutting depth in mm
W Cutting width in mm
f Feedrate in mm/min
N s
f
S f
f
D
L
Spindle turning speed in rpm
Mechanical efficiency (varies from 0.7 to 0.8)
d
V = ·d·N s
1000
P c = K s ·d·L·v
60·1000· c
(m/min)
= d·L·v
S c · c
Cutting efficiency. Cutting volume per kilowatt every minute
(cm³/kW)/min
f
P f = K s ·d·W·f
60·1000²· f
d·W·f
=
1000²·Sf ·f (kW)
(kW)