Die & Mould Making - CNC - Computer Numerical Control

46
EXTENDED TOOLS IN ROUGHING OF A CAVITY
To maintain maximum
productivity when
roughing a cavity it is
important to choose a
series of extensions
for the cutter. It is a
very bad compromise
to start with the longest
extension, as the
productivity will be very low.
It is recommended to change to extended
tools at pre-determined positions in the
program. The geometry of the die or mould
decides where to change.
Cutting data should also be adapted to
each tool length to keep up maximum
productivity.
When the total tool length, from the gauge
line to the lowest point on the cutting
edge, exceeds 4-5 times the diameter at the
gauge line, tuned, tapered bars should be
used. Or, if the bending stiffness must be
radically increased, extensions made of
heavy metal should be used.
When using extended tools it is important
to choose biggest possible diameter on the
extensions and adaptors relatively to the
cutter diameter. Every millimeter is important
for maximum rigidity, stiffness and
productivity. It is not necessary to have more
than 1 mm radially in difference between
holding and cutting tool. The easiest way
to achieve this is to use oversized cutters.
Modular tools increases the flexibility and
the number of tool combination
possibilities.