Fagor QC-PDS - Page 183

 Selection criteria
SELECTING CRITERIA
Asynchronous motor selection
5.
· 183 ·
Ref.2003
QC-PDS
HARDWARE
For lathe work, a cutting blade presses against the part to be machined
while it turns. See figure F. H5/3
.
The power required, P
c
is calculated as follows:
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 in this case P
f
is calculated as follows:
For drill work, the bit is mounted on the spindle and turns with it to drill
into the material. See figure F. H5/5
.
F. H5/3
Machining for lathe. Cutting power.
V
Cutting speed in m/min
K
s
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
Spindle turning speed in rpm

c
Mechanical efficiency (varies from 0.7 to 0.85)
S
c
Cutting efficiency. Cutting volume per kilowatt every minute
in (cm³/kW)/min
F. H5/4
Machining for mill. Cutting power.
K
s
Relative cutting resistance in N/mm²
d
Cutting depth in mm
W
Cutting width in mm
f
Feedrate in mm / min
N
s
Spindle turning speed in rpm

f
Mechanical efficiency (varies from 0.7 to 0.8)
S
f
Cutting efficiency. Cutting volume per kilowatt every minute
(cm³/kW)/min
L
d
D
V =

·d·N
s
1000
(m/min)
P
c
=
K
s
·d·L·v
60·1000·

c
=
d·L·v
S
c
·

c
(kW)
f
f
P
f
=
K
s
·d·W·f
60·1000²·

f
=
d·W·f
1000²·S
f
·

f
(kW)