Owner manual

28
f
n
l
m
D
m1
Finishing
1) Select optimum insert style to suit com-
ponent/process.
2) Use optimized a
p
for that insert shape/
application choose feed
eg. CNMG 120408-SF 1105 – f
n
0.15
mm, a
p
0.25 mm.
3) Calculate SCL for component feature
eg. Dia 450 mm, l
m
= 150 mm.
4) Select cutting speed from:
CNMG 120408-SF 1105 a
p
0.25, f
n
0.15
mm’ diagram eg. v
c
= 50 m/min, see
page 30.
Spiral cutting length (SCL) predictive machining
SCL was introduced by Sandvik Coromant
for the machining of HRSA due to the typi-
cally short tool life. One insert normally
machines one pass and is then indexed. It
is important to be able to predict for:
•Roughing–addingastopintheprogram
to change the insert
•Finishing–cuttingdatawhichensures
that the pass is completed with a predict-
able wear so as not to have to change
during the cut or recut the pass.
SCL is a method of calculating the length
of cut required for a particular feature and
then confirming with our specific recommen-
dations to ensure a reliable process.
Each SCL graph is unique and only applica-
ble for that insert, geometry, grade, depth
of cut and material. For finishing we give
you a range of cutting speeds to allow for
different length of cut requirements. For
roughing we have identified the optimum
parameters for each insert style and give
you one length.
Application process flow
Roughing
1) Select optimum insert style to suit com-
ponent/process.
2) Use optimized v
c
, a
p
and f
n
for that
insert shape/application and note SCL
capability eg CNMX 1204A1-SM S05F
v
c
50 m/min, f
n
0.35 mm, a
p
1.7 mm.
3) Note SCL capability for that insert
SCL = 450 m, see page 30.
4) Calculate SCL for component feature
D
m1
= 450 mm, l
m
=150 mm.
5) Confirm calculated SCL with insert capa-
bilities – program required number of
insert changes
eg. 606/450 2 edges required.
SCL =
D
m1
x π
x
l
m
1000
f
n
SCL =
450 x 3.14
x
150
= 606 m
1000
0.35
SCL =
450 x 3.14
x
150
= 1414 m
1000
0.15
Note. How to calculate, see page 118-119.