August 2008 Edition
VERTICAL MACHINING CENTERS
Know Your Options
After it took advantage of a new machine’s high-speed option, a medical parts manufacturer saw immediate results
With repeat work, KBK workers can add the fixture, call up the program, and go, saving setup time
Just as there is no profit in missed opportunities, there are
also no advantages in neglecting the abilities of new equipment. Advanced
capabilities of a top-of-the-line machine don’t profit the owners if its
potentialities are not being used to capacity. That’s why it’s important to
learn to use all of the bells and whistles when putting a new purchase into
production. The expanded capabilities can save time and money.
KBK Tool & Mfg., Skokie, IL, specializes in CNC milling and
turning in almost any material. About 70 percent of the company’s machined parts
go into medical diagnostic equipment and surgical instruments.
"Those customers expect and require close tolerances and
ultra-precision parts. They are uncompromising," Ken Hedeen, owner of KBK, said.
"We keep them happy with parts produced on the Bridgeport 760 XP³ machine."
With its high-speed option, the vertical machining center
from Bridgeport, Elmira, NY, a division of Hardinge, Inc., has improved KBK’s
operation by decreasing cycle times, thereby providing a faster turnaround for
its customers.
Surprising Speeds
A job that took four to eight hours for programming and setup has been replaced by putting on a fixture plate and calling up the program. The difference is time-in-cut instead of idle time.
"When I began looking for a machining center I wasn’t aware
that Bridgeport had high-end solutions," Hedeen said. "When I read the company’s
product brochure I was impressed by the specifications. That’s what really got
me interested. I figured no one would put those capabilities in writing if the
machines couldn’t perform them."
After purchase, KBK put it to immediate use. But, the
machine’s fast setup left the company unaware of its high-speed options until
Kyle Klaver, an applications engineer from Bridgeport, showed KBK the parts it
was producing could be made at much faster feed rates, within the same tolerance
bandwidth.
"Klaver blew us away," Hedeen said. "We’d been interpolating
at 6 ipm, that shot up to 30 ipm. What really got our attention were cycle
times, they dropped by one-third."
KBK was making aluminum parts with cycle times of 45 to 50
minutes. By making full use of the Bridgeport’s capabilities, times were cut by
30 percent.
Crucial Turnaround
Hedeen said that customers aren’t willing to wait two weeks
for order fulfillment and with the Bridgeport added to KBK’s machine arsenal,
they don’t have to. The higher-end technology lets the company turn jobs faster,
with more efficiency.
"We often use fixture plates on the machine, especially if we
know we’re going to be repeating the job," he said. "With repeat work, we throw
on the fixture, call up the program, and go."
Programming a part on the Fanuc control for the Bridgeport 760XP3, a KBK operator was able to hold a true position of 0.001" without making any adjustments
Hedeen said he likes the 30-tool, side-mounted, swing-arm
automatic tool changer as well, because the operator can leave tools in the
changer for repeat jobs, making setup time negligible – the tools are there,
ready for use when the program is loaded in the control.
"A job that may have taken four to eight hours for
programming and setup has been replaced by putting on a fixture plate and
calling up the program. The difference is time-in-cut instead of idle time,"
Hedeen said.
The other thing that Hedeen said he likes about the
Bridgeport toolchanger is that it’s mounted to a supported shoulder on the
machine’s column, engineered to support its weight. This eliminates vibration
transfer into the cutter while the tool changer is rotating.
Hitting Unthinkable Tolerances
After acquiring the Bridgeport, KBK acquired a Zeiss CMM. The
company uses it to certify its products to provide traceability for the parts it
makes for the medical and aerospace industries.
"It’s exciting to run a new part on the
Bridgeport and put it in the CMM," Hedeen said. "We
just look at each other and say, ‘Wow,’ because the part’s
right on. We’re hitting tolerances of 0.0005", total – not
plus or minus – and we hit 0.0003" as well.
"My programmer came to me and said he’s
holding true position of 0.001"
and the first programmed part came out perfect. He didn’t
have to make any adjustments, and he’d never been able to do
that in his years of programming experience," Hedeen said.
KBK is able to go after jobs it couldn’t
before learning to ring the machine’s bells and blow its
whistles. Bridgeport
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What do you think?
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www.ModernApplicationsNews.com or e-mail the editor at
pnofel@nelsonpub.com.