GRINDING, HONING & SURFACE FINISHING TECHNOLOGY TO EXPAND HORIZONS
inserts. Says Thompson: “Traditional PCD
rotary cutting tools feature flat PCD tips
brazed onto a carbide tool body. While the
PCD will extend cutting edge life, by design
the cutting geometry is a shear (straight)
edge with a flat hook face. This inherently
limits the performance of the tool.”
With solid PCD-tipped tools, tool
designers can have greater flexibility to
create unique geometries specific to
various cutting applications, in the same
way this is done for conventional carbide
tools, he says, with this applying to not
only to the cutting profile but, importantly,
to flute and gash geometry, both critical
to chip formation and evacuation.
He continues: “Another important
consideration is that while the smallest
tool diameter for brazed PCD tools is
typically 6 mm, solid PCD-tipped tools can
be made much smaller. Micro tools –
drills and end-mills – are gaining
widespread use in the 3C market, with
the EDGe capable of producing drills of
0.3 mm and milling cutters under 3 mm.
“Finally, unlike coated carbide tools,
these new drills and end-mills can be
resharpened many times, effectively
extending the tool’s usable life.”
Referring specifically to the EDGe
machines, ANCA highlights that of all the
forms of PCD machining processes,
rotary erosion that is used by the EDGe
is by far the best suited to producing
solid PCD-tipped drills and end-mills. Wire
erosion cannot create flute or gash
forms, and laser ablation has highly
expensive upfront costs and is ultimately
uneconomical on anything but the very
smallest of solid tools.
ANCA’s EDGe has both electrical
discharge machining and carbide
grinding capability. This is an important
consideration, given that these solid
PCD-tipped tools will naturally require
the flute and OD form to extend into
the carbide. With both electrical
discharge machining and grinding
capability, ANCA says users have
the choice to select the optimal
process for different materials. ■
Solid PCD-tipped tools are now
easily manufactured on ANCA’s
EDGe, courtesy of new
software
tools of 300-off was produced automatically
using the Rollomatic’s fully integrated robot
loader for lights-out running overnight, the
company reports. Produced to high quality
and well within the desired tolerances across
the entire batch, the cycle time from solid bar
was under eight minutes.
Marlor makes full use of the easy-to-set
auto loader during the evenings and nights,
and manufactures lower quantity special tools
during the day. Cross reports that the quality,
surface finish and repeatability from the
machine are stunning, whilst the extended
wheel life and dressing frequencies have
been a revelation. Cycle times have been
dramatically reduced, with the company citing
another example of a long-length throughcoolant
drill for an aerospace application that
used to take seven minutes to manufacture
but is now produced in two on the Rollomatic
machine. In quantifying improvements in
quality, Marlor says the Rollomatic
easily holds tolerances of under
3 micron on tool diameters
over larger batches of tools
and previously it simply
couldn’t achieve that.
A new software
development is allowing
those with ANCA tool
grinding machines to enter
different markets, too. Explains
ANCA ( www.is.gd/sibuja ) with
respect to the new software for its EDGe
machine: “Those with existing machines now
have opportunity to create new tool
geometries not possible before.” The
company is talking about solid PCD helical
end-mills and drills. As a 5-axis CNC
machine, the ANCA EDGe with its rotary
EDGe process is ideally suited to create
complex 3D cutting tool forms and can now
do so for such tools.
Continues the company: “There has
always been a demand for end-mill type
cutters but, in the absence of a
manufacturing method to make such tools
out of solid PCD, they were
normally made with brazed
planar PCD on a carbide body.
Now, with the new end-mill
software and availability of
solid PCD-tipped tools, we
have an option to make these
new helical tools that can be expected to
have better cutting performance. It gives
customers options for new tool types that
might allow them to differentiate themselves
in the market.”
The demand for these types of end-mill
tools is coming from customers operating in
the 3C (electronics manufacturing) market,
mostly in Asia, but the solid tipped drills
have applications in aerospace market,
for CFRP stack hole drilling. For the latter
market, customers making these tools
are predominantly in the US and Europe,
ANCA advises.
Duncan Thompson, product manager
at ANCA, who is responsible for the
technical direction and commercialisation
of new machine and application
developments, explains in more detail
about the new development and its
importance. “This capability is coming
at just the right time for PCD
cutting tool
manufacturers, as
there is an alignment
of market and
technology
developments
making solid tipped
PCD tools
economical and
desirable. Users of
PCD tools are asking for
longer life and better cutting
performance than is possible with a
shear cutting edge on a traditional PCD
tool. The aerospace and 3C industries, in
particular, are driving this. Additionally,
the solid PCD tip production processes
have matured and with that have become
more affordable.”
Solid PCD-tipped tools offer
advantages. Most important is the
complete flexibility in tool geometry.
The EDGe machine’s ToolRoom
software now allows users to create
helical cutting tools, both drills and
end-mills, that boast far superior
cutting
properties,
compared to
equivalent
tools that
have brazed
planar PCD
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