Hommer Tool and Manufacturing Company (Arlington Heights, Illinois)
employs about 40 people. Its equipment includes six CNC lathes,
one CNC machining center, grinding, honing and wire EDM equipment.
The company emphasizes precision processes and quality workmanship.
It accepts mostly shorter run jobs with tight tolerances, many for
the injection molding industry.
James "JR" Hommer, vice president, was looking for a way to
reduce the time it took to complete a very difficult boring job.
The job took 21 minutes per part to complete with multiple roughing
and finishing processes. It required 10 minutes of hone time.
The material used for the cylindrical workpiece was Inconel,
a strong, resilient aerospace alloy that can be tough to machine.
Hommer Tool, a job shop specializing in close tolerance round tooling,
had to remove 0.060 inch of material and keep tolerance within ±
0.0005 inch.
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Hommer Tool and Manufacturing Company dispensed
with its honing operation and reduced the multiple roughing
and finishing processes to a single, two-sided operation on
a lathe using BIG Kaiser's twin cutter roughing head. This reduced
the job time by 12 minutes.
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The diameter of the bore was 1.290 inches and the depth was 9 inches—a
diameter to length ratio that would exceed any published standards,
according to Mr. Hommer.
Application engineer Jeff Stone of BIG Kaiser
Precision Tooling, Inc. (Elk Grove Village, Illinois), and distributor
Tom Senger, West Side Industrial Supply (South Elgin, Illinois),
came up with a possible solution. They proposed dispensing with
the honing operation and reducing the multiple roughing and finishing
processes to a single, two-sided operation on a lathe using BIG Kaiser's
10.315.301 twin cutter roughing head.
BIG Kaiser twin cutters have not often been considered for applications
on lathes, and Mr. Hommer had to be persuaded that the same tool
would do both roughing and finishing within the tight tolerance.
"No one had samples to prove the process," he says. "It was putting
a lot of risk on me." On the other hand, none of Hommer's other
tooling suppliers had a competitive bid for the job, so Mr. Hommer
decided to take the chance.
Everyone was pleased with the results. "It cut a 21-minute job
to 9 minutes" Mr. Hommer says. Considering that Hommer's contract
called for producing 2,000 of these pieces for a military application,
saving 12 minutes per piece meant significant cost reduction.
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Left to right: Jeff Stone, JR Hommer and
Tom Senger display the tooling and workpiece.
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"We don't like to talk specific dollars, but we can say that Kaiser
tooling helped to make this a profitable contract," Mr. Hommer says.
"We used a carbide bar with coolant through," says Mr. Stone. "The
bar length was 13.8 inches, long enough to cut a bore 12.1 inches
deep. This is an in-stock item at BIG Kaiser, where our competition
was quoting specials."
"Running a twin cutter on a lathe requires much closer attention
to setup detail than in rotating tool applications," Mr. Stone adds.
"We have to align the inserts parallel to the ways of the machine.
In this case, we were using one insert for roughing and the other
side for finishing, making two operations with the same tool. The
cutting edges of the inserts have to be positioned precisely on
the centerline and the length of the tool must be precisely parallel
to the centerline of the bore to be machined."
Hommer used a 11.654.968 TiAlN-coated insert. They roughed out
0.040 inch at 100 SFM/0.003 IPR and finished at 200 SFM/1.8 IPR,
removing 0.020 inch of material.
"‘Never been done' has never been a term in our vocabulary,"
says Mr. Hommer. "We welcome new manufacturing challenges!"