Schnipke Engraving Co.

Automatic Wire-changing EDM Gives Business
Surgical Precision
Founded more than 50 years ago as a family-owned industrial
engraving business, Schnipke Engraving Co. in Ottoville, Ohio,
has evolved into a dual-facility organization that specializes
in ultra-precision injection molding as well as automated and
manual assembly. These and other exacting manufacturing
processes, such as electrical discharge machining (EDM) with
automatic wire changing capability, allow their tooling division
to generate complex molds engineered for critical applications
in the medical, defense, aerospace, and other precision
demanding industries.
According to John Hoskins, director of sales and marketing
at Schnipke Engraving, the company continues to follow
its founder, Leonard Schnipke’s mantra. “The impossible we
do immediately. The miracles take a little longer.” In following
this philosophy and serving its diversified customer base,
the Schnipke Engraving has pioneered and developed a wide
range of productive and proprietary processes.
Schnipke Engraving exacts precise control over its production
processes – from the fabrication of molds to the actual injection
molding and through to the assembly of tight-tolerance
components. And Ron Schnipke, Leonard’s son and vice president
of tooling, said that the company consistently designs,
fabricates molds and produces components that meet and
exceed customer requirements. In fact, the Schnipke Engraving’s
mold manufacturing methods have continuously evolved
in parallel with business growth and customer demands for
increasingly complex molded products.
As part of its high-precision moldmaking operations, Schnipke
Engraving’s EDM equipment is a key manufacturing technology.
“When we started designing and fabricating mold cavities,
EDM came right along with it,” said Ron Schnipke.
The tool room’s first EDM machine was a manual die sinker,
and today, Schnipke Engraving employs a sinker as well as
several wire-type EDMs. Of all its EDMs, the company’s most
recently acquired system is an AgieCharmilles CUT 3000 wire
EDM from GF Machining Solutions that features dual-wire
spools and automatic wire changing.
With twin wire spool capacity, the CUT 3000 permits immediate
and fully automatic wire changing capability for switching
from one wire diameter to another. “We needed something
that we could change over quickly.” Schnipke said. With other
wire EDM machines, changing wire diameters is time consuming
– the new machine takes less than a minute to switch,
without operator intervention. The CUT 3000’s wire guide
system allows for using wire diameters from 0.002” (0.05 mm
or slightly less than the diameter of a human hair) up to 0.012”
(0.30 mm).
The AgieCharmilles CUT 3000 uses patented GF Machining
Solutions Universal Wire Guide technology. Two stationary
three-point V-guides – an upper and lower – are all that is
required to accommodate the wide scope of wire diameters.
Operators simply enter the desired wire diameter size into
the machine’s control, and the guides compensate for the
difference between one wire diameter and the next. But most
importantly, the machine is always aware of wire center to
maintain exact part location and size once a wire diameter
change has occurred and cutting resumes.
All of Schnipke Engraving’s EDMs can run lights out for continuous
production and maximized machine utilization time.
However, Schnipke added that the newer CUT 3000 takes the
tool room to the next level when it comes to speed, accuracy
and very fine, intricate high-precision cuts. Plus, with automatic
wire changing, parts can be roughed using more costeffective
large-diameter wire, then, finish cut with high-end
high-performance smaller-diameter wire to get the desired
radii in the corners.
While the mold building facility occasionally uses copper EDM
wire, it generally works with stratified wire. Schnipke Engraving
normally use copper electrodes on the sinker EDM, along
with a wide range of tool steels for their molds.
Where appropriate, Schnipke Engraving produces micro-scale
mold features via high-speed milling. The shop considers a
0.250”-diameter cutter to be “large,” and the application of
0.080”-diameter and 0.040”-diameter tools is commonplace.
Tom DePotter, director of new product development, said,
“Schnipke Engraving combines a variety of tactics to ensure
that its processes are robust and consistent. The company’s
advanced CAD system, for instance, enables us to create 3D
models of molds and rotate them to see every aspect of the
mold. Sigma Soft analysis software helps predict how the
component material will move through the mold. It’s this application
of technology that allows us to get it right the first
time,” DePotter said.
Verifying fabrication results are as important as controlling
the molding processes itself. “Completed parts of the molds
get measured in the QA lab or machine side,” added Schnipke.
“On-machine probing can generate problems if you have any
wear on the ball screws. If you don’t measure your tooled
pieces off line, you are measuring any possible error right into
the mold measurements itself, versus utilizing an independent
measuring system.”
Schnipke Engraving has developed its own automation technologies
to maximize productivity and part accuracy, which
have revolutionized the production and assembly of many
surgical device components.
The combination of advanced fabrication processes, EDM and
high precision machining, intelligent automation and lean
principles continue to enhance Schnipke Engraving’s capability
to respond quickly to customer demands. Hoskins said,
“Faster fabrication helps us condense our lead times. Our
customers are constantly asking us to go faster. We are part of
their product development process. They have market windows
when they introduce new product; we have to hit their
target objectives, because if they miss their window they lose
their competitive edge.”