12
Kongsberg XN / iPC 2.0
93
Acrylic or Multi Purpose bits
1. Acrylic Bits
(A) are polished, extra sharp for
acrylic, wood etc.
2. Multi Purpose Bits
(MP) have a higher
wear resistance, and are suitable for
aluface, plastics, MDF, plywood, wood etc.
Multi Purpose Bits
can be identified by a
small tooth at the tip (left hand bit on the
picture).
Feed rates
One-flute Bits
do have a good chip flow, and
allow for large feed rates. 0.1-0.2 mm/tooth
(0.004-0.008 in/tooth) can be a starting point
for optimization in most materials:
This gives a feed rate of of 4-8 m/min (2.6-5.2
ips) at 40.000 RPM, and 6-12 m/min (3.9-7.9
ips) at 60.000 RPM.
Light materials, like PVC foam can be run much
faster.
The surface finish or the
Power Consumption
will normally determine the final
Feed Rate
for
an application.
A large drop in RPM, or a high %Watt value in
the display, indicate too high
Feed Rate
.
Large diameter bits require more power than
small diameter bits.
Worn bits increase the
Power Consumption
.
Number of passes in thick materials
The
Number of Passes
depends on
Material Type
,
Milling Depth
and
Bit Diameter
.
Use a
Pass Depth
that makes the groove free of chips, normally that is a depth equal to the
Milling Diameter
.
Material hold down
Material Hold Down
may be a limiting factor. Small parts cut loose can be a problem.
This can be done to improve the situation:
1.
Use
Milling Bits
with smaller
Milling diameter
.
