|
Company engineers looked at a variety of options available to them. Quality,
reliability and performance testing led them to the Makino A-Series horizontal
machining centers (HMCs) as the best fit for the company’s needs.
According to Danny Burleson, manufacturing engineer at Curtiss-Wright Motion
Control, the group now operates three Makino Horizontal Machining Centers (HMCs):
2 A55Es and 1 A77E with an added fifth-axis. “We have realized great
time-savings and efficiency with the Makinos, well beyond what was originally
anticipated in the initial testing—with an uptime of about 98 percent,” says
Burleson.
A Pioneering Company
Curtiss-Wright was incorporated in 1919, but the roots of the company date
back to the first powered flight in 1903. By World War I, founder Glenn Curtiss
had grown the company into the largest aircraft manufacturer in the world,
producing more than 10,000 planes
during the span of the war. This equates to more than 100 planes a week!
Eventually the company grew, acquiring a variety of other companies including
Wright Aeronautical, the company founded by the Wright Brothers. It was listed
on the New York Stock Exchange in 1929 as Curtiss-Wright Corporation, where it
still trades today.
The Curtiss-Wright Corporation now operates in three business segments:
Motion Control, Flow Control and Metal Treatment. While about half of the
company’s sales are related to aerospace, the other half are spread over a large
number of markets. Headquartered in Roseland, New Jersey, the company has
manufacturing, distribution and parts facilities around the world, including the
Shelby location.
Investigating the Options
When Danny Burleson looks to replace a machine, he looks at maintenance
records and the cost of upkeep in making determinations on which machines are simply costing more to operate than
they are producing.
Three years ago, Burleson wanted to upgrade a twin-spindle machining
center that the company used to
manufacture aluminum transmission housings for commercial aircraft.
He says he was looking for speed,
reliability and accuracy in his decision making. He also had very strict
tolerances that had to be met for the aerospace work that he would be doing with
the machine.
He attended a high-speed machining seminar at Makino, sent the programs and
specs for a transmission housing test to Makino and his local distributor,
Beckman Precision, and he was impressed with the results.
“We wanted to see what the cycle time would actually be—to see the gain we
would get with Makino,” Burleson says. “We needed a machine that would give us
the most speed and still maintain accuracy, with Z-axis positioning critical. We
have a tight positional tolerance on two holes that are 12 inches apart.”
Service was also at the top of the list in buying a new machine from
Burleson’s point of view. Not only the availability of technicians but also of
spare parts.
Burleson’s first perception of Makino’s service was realized when he
contacted the company for pre-sale information, and he says the experience
overall has been great. After the machine was installed at the company, and a
comprehensive training course was conducted, the machine was able to produce
parts immediately.
“The aerospace industry involves a lot of technology and Makino offers
support and technical advice whenever we need it,” Burleson says. “Makino also
offers free seminars throughout the year on topics that include both high-speed
machining and aerospace topics that Curtiss-Wright continues to take advantage
of today.”
Immediately Measurable Results
Curtiss-Wright used that first Makino A55E with a pallet changer to
manufacture aluminum housings for commercial aircraft including a transmission
housing for a Boeing 737-700 Trailing Edge Wing Flap Actuator. The spindle
allows for
additional face taper contact, which Burleson says is imperative to his
operations.
Cycle times on this part have surpassed Burleson’s expectations. “We had a 30
percent cycle time reduction on the transmission housings just with the speed of
the machine. Once we optimized our programming, and took advantage of the
spindle speed and the high-pressure coolant—especially on deep-hole
drilling—we’ve seen improvements of close to 50 percent. And, we’ve eliminated 5
tools from the process through cluster tooling.”
 |
 |
 |
| Curtiss-Wright had a 30 percent cycle time reduction in machining aluminum transmission housings. |
Tool accuracy is maintained across the board, and from tool change to tool
change. The company has seen an increase in repeatability from +/-0.0001 to +/-
0.00008, and an automatic tool change savings of 1.6 seconds per change. “All of
our parts—all of our housings—are checked 100 percent
on the CMM and everything is great,” says Burleson.
Tool life savings of 25 to 30 percent has been gained with the Makino because
operators can push the spindle beyond what they’ve been able to do with other
machines. “We have permanent packages where we have to take the tool holders out
of the machine and set them aside,” Burleson says. “Most of these are boring
bars. When we replace them we don’t have to go back and readjust to maintain
tolerances.”
Productivity has also increased measurably as well on the housing. “In 2000,
when we purchased the A55E, we were up to 22 ship sets. There were 8 housings
per ship set, per month totaling 194.3 hours. That went down to 126.19 hours per
month, at a savings of 36
percent in time alone,” Burleson says.
When Curtiss-Wright bought the first A55E, the company intended to only
machine 3 housings on it instead of the 4 it was machining on its existing
twin-spindle machine. But, Burleson says with the speed and accuracy seen with
the Makino, the company was able to increase this number to 5—which
automatically increased projected output production by 40 percent.
|
|
|
The second A55E has given the company a 36 percent improvement
over previous processes machining F-16 tie bars made of 13-8 stainless.
|
|
|
In-house capabilities have improved through lean manufacturing using the
Makino, so all parts only travel 528 ft internally, down from 896 ft. Two hours
are saved in set-up, down to 1.5 hours from 3.5, and run time is down to 58
minutes from 85 minutes with a 31
percent or 27-minute savings in time.
Customer Satisfaction
Based on the company’s success with
the Makino A55E, when it came time to upgrade another horizontal machining
center, Burleson says he went back to Makino for a second machine. On the second
A55E and on the subsequent A77E with a fifth-axis table, stainless steel tiebars
are machined for military vehicles.
Both of these machines are used exclusively for stainless steel machining.
Burleson says the second A55E has given the company a 36 percent improvement
over previous processes machining F-16 tie bars made of 13-8 stainless.
Because the parts are manufactured for internal use, Burleson says his own
internal customers can seem more demanding than external customers.
He says that anytime he is faced with choosing the proper machine for incoming
jobs, the Makino is always considered. This is especially true if the part
requires tight tolerances, sizes, position or is just a very complex part. “Not
that our other machines aren’t accurate,” Burleson says, “but the Makinos are
probably the top machines on the shop floor right now.
“When we brought the first Makino into production,” Burleson says, “everyone
saw the speed of it versus the other machines and they were amazed at how fast
it rapids and how fast tool changes are. It has gotten a lot of attention.”
In fact, Burleson says that the maintenance engineers at Curtiss-Wright were
concerned that the speed of the machine would mean more mechanical problems and
downtime. But, with an uptime of 98 percent that has certainly not proven to be
the case.
Burleson and Larry Broome, a machinist for Curtiss-Wright in the Motion
Control area, both agree that the Makino machines have made their jobs easier.
“Operators love to run the machines,” Burleson says. “They’re good machines and
very user friendly. And, not only does that make the Makinos look good, it makes
me look good!”
Broome says the other operators don’t mind filling in for him on the Makino.
“They call it gravy all the time because it is so good to run!”
|
