is featured in the cover story of Tooling
While walls shake, tools keep part in spec...
As published in Tooling and Production
A material called FR4 is a glass-filled plastic, difficult
to machine and very abrasive on tooling. It is one
of several materials used by Fluke Metal Products Inc.
in Bothell, WA, to produce precision devices for avionics,
medical equipment, surface mount technology and electromechanical
On a typical production day earlier this year, a 12´´-diameter
flat ring of this FR4 material was being machined with
an IBAG HF100 high-speed spindle integrated in a Compumachine
Vibra-Free vertical machining center.
Robert Fluke (right), president of Fluke Metal Products,
and George Passino, manufacturing engineering manager,
inspect a precision- machined FR4 ring component
in front of the company's IBAG-equipped VMCs.
Four-hundred square pockets, each 0.022´´ x
0.022´´ x 0.065´´ deep, were
being milled at 45,000 rpm using a 0.10´´ diameter
carbide end drill. By way of a size comparison, that
tool's diameter is about three times the thickness
of a human hair.
The machining conditions were challenging enough by
most standards. Then they got tougher. An earthquake
hit--literally. Mick Crotts, CNC operator at Fluke,
comments on what happened next:
"I was well into the job when the earthquake
hit. It was big--a 6.8 on the scale. The room was shaking,
the lights started swinging, I thought the building
was going to come down. We all ran outside and waited
until it was over. When I came back in, the machine
was still running at 45,000 rpm, milling the tiny pockets.
The cutter hadn't broken, but one of the concrete building
floors had a crack about a half-inch wide and five
When the dust had settled, Crotts took the finished
part off the machine and brought it up to Quality Control
(QC) for checking.
"It was amazing," he says. "The part
was perfect. I can't believe the rigidity of that IBAG
spindle and the Vibra-Free machine. Even though everything
in here was shaking like crazy, the part came out right
History of quality
Robert Fluke is president of the company his father
founded in 1957. He oversees a facility that employs
65 people and runs 24 hours a day, Monday through
Thursday and two eight-hour shifts the rest of the
week. Most of the people at Fluke Metal Products
have exceptionally long tenure, take advantage of
the overtime opportunities and display a strong sense
of company loyalty and pride in their craft.
Machining 0.022´´ x .022´´ x
0.65´´ deep pockets in glass-filled, abrasive,
FR4 material with a 0.010´´ diameter end
mill at 45,000 rpm. The IBAG HF100 high-speed spindle
provides excellent rigidity and concentricity for a
tool that is only three times the thickness of a human
"Over the years," says Fluke, "we've
evolved from a design engineering firm into a production
company specializing in close tolerance components
and assemblies. In addition to our CNC lathes, turning
centers, machining centers and other production equipment,
we have an extensively equipped QC department."
Unusual for a company of this size are six full-time
QC specialists to verify the customers' specifications
on all part runs. Verification printouts are provided
on request at no charge. In addition, parts are deburred
to a 20-power magnification as a value added service,
"Quality is number one," says Fluke, "then
delivery, then price. When we marry all three criteria
together, then we have a happy customer that stays
Need for speed
Customers do stay with Fluke Metal Products, from Washington
to North Carolina, to New York and New Jersey. The
company's reputation for delivering intricately machined
precision components, in short batches, encouraged
Fluke to take the next step--from traditional production
machining to high-speed production machining.
"We needed more rpm," he says. "The
speed from the machines we had just wasn't enough.
Our average batch runs on the machining centers are
between 50 to 100 parts. That calls for frequent changeovers
and setups. We had to have faster throughput, and that
calls for faster rpm and more productive chip loads.
The faster we can mill the pocket, so to speak, the
better we can get our prices in line with the customer's
perspective. We had to go to high-speed machining to
CNC operator Mick Crosby holds a glass-filled plastic
ring component similar to the one that was machined
'perfectly' despite being in-the-cut during a 6.8
Fluke dispatched three of his top people to IMTS 2000
in Chicago to check out high-speed vertical machining
centers. They quickly narrowed the field from several
down to the Vibra-Free with the HF100 IBAG spindle.
Featuring hybrid ceramic ball bearings, an open-loop
Vector control and a chilled water cooling system,
the IBAG HF100 spindle delivers up to 50,000 rpm at
After witnessing the success of their first machine,
they soon had a second Vibra-Free VMC installed, also
with the IBAG HF100 high-speed spindle. This machine,
though, was a 5-axis model that incorporated a rotary
table (C-axis) on a trunnion (A-axis), with all five
axes under the machine's Fanuc 16i CNC control.
A+ tooling system
George Passino, Fluke's manufacturing engineering manager,
especially likes IBAG's SKI-25 tooling system. "With
a lot of other systems," he says, "you
have to go to a comparator and actually dial in each
of the tools to the holder. With the IBAG SKI-25,
we typically just insert the tool and begin machining.
Because of the quality of the holder, we rarely even
check them any more. That means one less thing our
operators have to do when they're constantly changing
tools, changing parts, changing setups."
Passino reviewed some of the jobs currently being
machined with the IBAG high-speed spindles.
"This part is made of Techtron PPS," he
says, holding a tiny part up to the light to show off
its fine detailing. "It's a high-heat part, one
of a family of five similar parts used to guide wires
in a capacitor-checking machine for the computer industry.
Using a 0.015´´-diameter end mill, we take
a series of eight cuts of about 0.010´´ deep
at 45,000 rpm and a feedrate of 30 ipm. It's a very
good test of the spindle's rigidity and concentricity
since the thickness of each wall of the wire guides
is only .010´´. The machining cycle is
only a few minutes, compared to the 30 minutes it took
previously on a more traditional VMC at 15,000 rpm."
Referring to the part that was being machined during
the earthquake, Passino says they had previously tried
machining the part on the 15,000-rpm VMC. Completing
the job took close to four hours. With the IBAG spindle
on the Vibra-Free, the job is completed in 80 minutes.
That includes not only the 400 0.022´´ x
0.022´´ pockets, but also 400 pocket "tails," each
0.120´´ long x 0.015´´ wide
x 0.018´´ deep. Each corner radius generated
is 0.005´´. Repeatability is exact for
each pocket and each tail. There is no margin for error
because of the super-accurate end use of the part in
a capacitor check-sort system.
On the 5-axis machine, the 50,000-rpm IBAG spindle
is at work machining a capacitor insert test plate.
The material is the highly abrasive, glass-filled FR4
plastic. A 2´´-diameter wheel cutter on
a 3´´-long shaft cuts 18 positioning slots
at 20-ipm feedrate.
"Three inches is a long reach to get to the part," says
Passino, "and would make a lot of people nervous
in high-speed machining. But this IBAG spindle is very
rigid and does a great job at handling that long length
with a big diameter wheel."
A second wheel cutter puts in 60-degree angles at
60-ipm feedrate. Then, 0.014´´- and 0.020´´ diameter
long-reach end mills complete the final geometries
of the slotted part. The finished parts are assembled
into a circular component used in four-array capacitor
This Techtron PPS wire guide features 0.010´´ thick
walls cut to a depth of 0.080´´ at 45,000
rpm with the IBAG high-speed spindle in 6 minutes versus
35 minutes with a conventional 15,000-rpm spindle.
Back on the 3-axis Vibra-Free, the IBAG HF100 spindle
is realizing a 30-percent time savings in machining
a pair of aluminum avionics parts. Each will serve
as an LCD frame with pockets for control and call-up
"All the parts we produce have a common thread," says
Passino. "They are close tolerance, high-precision
components that have some sort of cosmetic, value-added
finish to them. Because of the precision and complexity
of the components, we machine almost all of the fixturing
and tooling for them right here on the Vibra-Free VMCs
with the IBAG spindles. If the part has to be to 0.0002´´ tolerance,
the fixture must be no more than 0.0001´´ tolerance.
The fixture has to be half or less in order to give
us the opportunity to hit the nominal on the part."
According to Fluke, the direction his company is taking
will be more and more into the high-speed end of machining. "We
have to keep ourselves positioned on the cutting edge
of machining technology" he asserts, "so
that we can continue to support our customers better
than our competition."