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Ingersoll was founded in
Cleveland, OH in 1887, primarily as a heavy machine manufacturer. The
company moved to Rockford, IL shortly thereafter and has operated at its
present location for more than a century. Ingersoll International employs
about 4,000 people, worldwide: approximately 2,000 in the U.S. and about the
same number in Germany. Ingersoll subsidiaries focus primarily on the
manufacture of special machine tools and cutting tools.
 Ingersoll
Cutting Tool Company in Rockford employs about 550 people and consists of
three facilities: steel products, with about 40,000 sq.-ft. of manufacturing
space; carbide inserts, with about 28,000 sq.-ft. of production space; and a
prototype and repair center. Scott Wenstrom, senior manufacturing engineer
in steel products, has responsibility on the shop floor for just about all
aspects of cutting tool production; including fixture design,
troubleshooting, and assigning required work to the proper machines. With 15
years’ experience at Ingersoll Cutting Tools, and 10 years in his current
position, he supports the activities of nearly 100 people involved in
manufacturing precision cutter bodies.
The cutting tools produced in
the steel products shop are mainly for unique applications, with about 36%
being standard designs and 64% specials. During 1999, steel products volume
totaled about 40,000 units, although this figure is not entirely
representative of the overall manufacturing picture. The tooling ranges in
size from small ½" diameter endmills to aluminum scalpers with diameters in
excess of 100". Typical lot sizes vary from one to 30 pieces for a wide
variety of standard, nonstandard, and engineering special tools. Much of the
tooling is manufactured specifically for its sister company, Ingersoll
Milling Machines, that is involved in making high-velocity (40,000 rpm)
milling machines.
 Most
of the shop’s production is batch-processed on 13 five-axis machining
centers, two CNC (computer numerical control) grinders, and an assortment of
manual grinders. Of the two CNC grinders, the Kellenberger Kel-Varia from
Hardinge Inc. (Elmira, NY) is the one used in making HSK-type high-speed
tools. Otherwise, standard tooling product is manufactured in a production
cell comprised of another CNC grinder and an assortment of other machines.
According to Wenstrom, the
Kel-Varia (the company’s first) was installed in December 1998. Previously,
the shop had one CNC grinder in its operation, with four other CNC grinders
installed at Ingersoll Milling Machines. With the pressure of increased
production volume and higher precision requirements, Ingersoll Cutting Tools
decided to expand the steel products shop by adding another CNC grinder.
While reviewing the alternatives, Wenstrom narrowed the search to the
Kellenberger machine. In the final analysis, having CNC on the B-axis and an
excellent reputation for service gave the nod to the Kel-Varia.
In making the decision,
Wenstrom studied machines in North Carolina, in the Milwaukee area, and
locally in Rockford that were involved in similar applications. Based on his
own experience and discussions with a North Carolina tooling manufacturer
(who was doing work similar to Ingersoll Cutting Tools), he was able to
collect some good information on the Kel-Varia’s operation. “When I talked
with their engineers and shop floor people to get their opinions on
service,” says Wenstrom, “the majority of the answers were, ‘We don’t know,
since we never had to use it.’”
What Makes Grinding
Integral HSK Tooling So Tough?
Ingersoll Cutting Tools was
one of the first cutting tool companies to pioneer in manufacturing HSK-type
tooling. Early in the 1990s, the company teamed up with Ingersoll Milling
Machines in a project to build a line called the “Ford Factory of the
Future.” This project featured the development of several groups of
high-speed machines and nontraditional transfer-line equipment with HSK
tooling.
Most of the tooling
manufactured to HSK designs is integral; that is, the shank and the cutting
tool are one piece. This is in direct contrast with several other makers of
cutting tools that use a standard adapter with an endmill. This two-piece
arrangement often has many inherent problems such as rigidity and runout.
However, according to Wenstrom, manufacturing the tooling as a single unit
presents some unique processing difficulties as well.
Inside the HSK taper, there
is a 30° clamping angle to accommodate the drawbar in the machine tool. From
the shoulder of the tool to that angle, there is a relatively tight
tolerance. Wenstrom explains, “If that were the only dimension that had to
be maintained to the shoulder (about ±0.001"), it wouldn’t be a problem. You
could measure the stock, grind the excess off the shoulder, and be done with
it. By making the tool integral, we also try to maintain a dimension over
the insert at the opposite end from the same shoulder. So, we end up holding
two dimensions from the same datum (or feature point) in opposite
directions. That makes a very small window where the shoulder must be
located.”
Wenstrom recalls that
Ingersoll Cutting Tool’s steel products shop learned a lot about the tight
tolerances involved, right from the beginning. “We knew what we wanted the
machine to do,” he says. “Unfortunately, the one grinding machine that we
had couldn’t do what we wanted it to do. The process was achievable, but it
was very labor-intensive.” Originally, manufacturing the HSK tooling
involved two separate operations. The taper and the shoulder were done in
one operation, followed by grinding the V-groove on another machine.
“Luckily, the operator at that time was very experienced,” he adds, “which
bridged the gap between the (manual) machine’s shortcomings and what was
needed.”
Now, the Kel-Varia’s setup
with in-process gauging and automation has made life a lot easier for the
shop. The machine’s features significantly reduce the cycle time and labor
involved in producing a good part. On average, depending on the particular
HSK tool design, a part that would take as much as 1½ hours of manual
grinding to complete now can be finished in 15 minutes. In addition,
grinding the tooling features in one setup on the Kel-Varia has paid
dividends for Ingersoll Cutting Tools by producing parts with precision the
first time, with much less scrap and wasted effort.
Another major advantage for
the Kel-Varia is its CNC B-axis, which gives it the ability to achieve much
more precise results. Accuracy and repeatability are further ensured by
having hydrostatic ways on the X- and Z-axes, where other grinders may have
this feature only on the Z-axis. Wenstrom is quick to point out that there
is nothing custom about their Kel-Varia. As far as delivery and installation
were concerned, he says, “We received the machine, and a week later the
service representative came in to train the operator and me. It went really
smooth, and he still supports the machine on a day-to-day basis, if needed.”
The Kel-Varia is
presently running on one shift, 10 hours per day, six days per week, with
the ability to expand to two shifts if needed. Most of the company’s HSK
tooling is manufactured for sale with the milling machines made by Ingersoll
Milling Machines. The market for this type of tooling to other customers is
expanding as well, although it is still a relatively narrow niche. As the
use of HSK tooling becomes more prominent in the marketplace, the steel
products section of Ingersoll Cutting Tools is positioned to manufacture
some of the most precise products of this type available anywhere.
Kellenberger, A Hardinge Co
- July 2000
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