G.H. Tool & Mold

Success Story:
G.H. Tool & Mold
EDM I Milling I Laser Texturing I Tooling & Automation I Customer Service

Auto Castings Fuel Shop’s High-Performance
Machining
The lighter automobiles become, the heavier the workload
gets at G. H. Tool & Mold. The Washington, Mo., business
specializes in aluminum die cast molds, serving practically
all the major automakers. And as those companies continue
to reduce the weight of cars in efforts to lower emissions and
conserve fuel, they do so by incorporating more die cast components
as opposed to stamped ones.
Automotive work makes up over 90 percent of G. H. Tool &
Mold’s output, and in the past, the 150-person shop produced
molds mostly for housing-type parts for power transfer
components, valve bodies, alternators and others. But over
the past couple of years, the shop has manufactured an equal
number of molds for structural and suspension components
as well.
The design-to-order company produces complete die cast
molds and replacement parts for existing molds in the field.
Job lot sizes are between one and 10 parts, most of which are
made from a superior grade tool steel. Part machining cycle
times vary anywhere from 30 minutes to eight hours, and
tolerances typically run between +/- 0.0005 to 0.002”. Service
parts for molds usually takes five weeks to finish, while a
complete mold is done in as little as 10 weeks.
To fulfill increased demand from its automotive customers,
G. H. Tool & Mold relies heavily on Mikron high-speed milling
machines along with a recently acquired Mikron highperformance
5-axis milling machine, all from GF Machining
Solutions (formerly GF AgieCharmilles) and acquired through
distributor Hartwig Inc. in St. Louis. These systems deliver the
speed, accuracy and surface finish capability the shop needs
to produce its high-quality precision molds in the shortest
amount of time possible.
G.H. Tool & Mold has three Mikron HSM (high-speed machining)
800 milling machines that sport 36,000-rpm spindles and
two HSM 500s with 42,000-rpm spindles. With these 3-axis
machines, the shop takes quick, light cuts using small diameter
cutters at high feedrates to shorten overall part cycle
times.
The newer 5-axis machine is a Mikron HPM (high-performance
machining) 800U-HD (High Dynamics) with a 20,000-
rpm spindle, 60-tool storage capacity and more power for
aggressive cuts – in both roughing and finishing operations.
The machine’s High Dynamics technology delivers 1G machine
acceleration rates, and the machine rapid traverses at 1,771.7
ipm in the X and Y axes and at 1,378 ipm in Z.
The HPM 800U-HD’s Step-Tec HSK A63 in-line spindle generates
63.7 ft-lbs of torque at 4,450 rpm for high metal removal
rates, while also providing the fast spindle speeds necessary
for producing superior part surface finishes. It incorporates
oil-lubricated ceramic hybrid bearings and is vector-controlled,
enabling thread cutting without the use of a compensating
chuck.
According to Danny Straatmann, programming manager at G.
H. Tool & Mold, the shop does practically all of its really critical
machining on the Mikrons. They are the shop’s “fast movers,”
he said, for lighter smaller components and for both soft
and hard machining – typically around 46-48 Rc. Their speed,
along with accuracy and rigidity, result in far better surface
finishes, and hard machining capability allows G. H. Tool &
Mold to mill parts to finished size from hardened materials,
thus reducing the amount of die-sinking electrical discharge
machining time required.
The Mikron machines get their extraordinary rigidity from
a special base material, yet they require no foundation. GF
Machining Solutions constructs its monobloc (single-casting)
machine bases from polymer granite that possesses extremely
high vibration-dampening properties, providing strength and
rigidity essential for high-speed, high-performance machining.
Single-casting constructions of the Mikron machines also
ensure machining accuracy and better thermal stability for
excellent workpiece surface quality and minimal tool wear.
Additionally, GF Machining Solutions outfits the machines

Whenever possible, the shop uses modular-type fixturing and
workholding systems from System 3R on its Mikron machines.
The modular systems make it possible to easily move parts
from one machine to another.
In addition to speed and rigidity, Straatmann pointed out that
ease of programming and control functionality are other key
benefits of the Mikron. For example, the shop’s HPM 800U-HD
features GF Machining Solutions’ Smart Machine functions.
These include spindle vibration control, crash protection and
monitoring.
Smart Machine functions detect any imbalance in cutting
tools, including instances where an operator improperly balances
a tool for high-speed machining. An unbalanced tool
can damage the machine’s spindle as well as ruin parts that
have undergone several valuable processing hours.
with absolute optical linear glass scales on the X, Y and Z axes
that operate with a measuring step of 0.02 µm to guarantee
unmatched positioning precision.
For its first foray into 5-axis machining, G. H. Tool & Mold
acquired two larger sized machines that achieved 5-axis capability
through spindle movement. These head/head-configured
machines, according to Straatmann, were fine for long narrow
parts, but fell short when it came to smaller more intricate
work.
“Often, with the two original machines, we’d have to reposition
parts to access certain features needing to be machined,”
explained Straatmann. “Plus, the spindle heads on these
machines – because they provide the 5-axis movement – are
really big, which lessens their agility and reach capability. Our
HPM 800U-HD, on the other hand, achieves simultaneous
5-axis motion through its tilt/rotary table. This configuration
moves the part around the spindle as opposed to moving the
spindle around the part. And because there is much less mass
to move around, the Mikron is an extremely faster and much
more accurate machine.”
The shop can also run shorter tooling on the Mikron – due to
its rotary/tilt table configuration – and thus easily access deep,
intricate part cavities. Plus, the table eliminates any issues
associated with long tooling overhangs.
The function basically monitors G acceleration and shops,
such as G. H. Tool & Mold, can set a specific level between 1
and 12 Gs. So, if the spindle reaches the specified force level,
the machine will automatically stop the process or initiate a
tool change to a properly balanced tool.
Besides fast spindle and axis speeds, a special tool changer
on the HPM 800U-HD also contributes to shorter part cycle
times at G. H. Tool & Mold. The changer is designed/mounted
at an angle, which places it closer to the spindle at one end.
Instead of the tool magazine being straight along the side of
the machine, it angles inside closer to the spindle. This shortens
the distance the spindle must travel for a tool change,
resulting in faster tool changes and reduced non-cut times.
Plus, the changer’s door will only close if tools are the proper
length. So if a tool is longer than the machine can accommodate,
the tool magazine door will not close.
Advanced machine designs and features, such as those on the
Mikron machines, enable G. H. Tool & Mold to further shorten
its die cast mold turnaround times and remain a go-to shop
for major automakers. And according to Straatmann, continuously
implementing new ways to boost efficiency and productivity
are essential for keeping pace with the surging automotive
industry.
As a result, G.H. Tool & Mold was able to transition many of its
smaller intricate parts from the older 5-axis machines to the
Mikron. And for many of those parts, the HPM 800U-HD not
only improved surface finish quality, but also slashed average
machining cycle times by half.
“We did look at other brands of machines, but cost-effectiveness
and machine performance, along with service and
support from both GF Machining Solutions and Hartwig,
convinced us to stay with Mikron. Every part run on our older
5-axis machines has undergone evaluation, and we now run
many of them on the HPM 800U-HD. If it fits within the machine
travels, we run it on that machine.”

GF Machining Solutions
GF Machining Solutions
560 Bond Street
Lincolnshire, IL, 60069
USA
Website: www.gfms.com/us
Email: info.gfms.us@georgfischer.com
Phone: 847-913-5300
© Machining Solutions, 2015
The technical data and illustrations are not binding.
They are not warranted characteristics and are
subject to change.
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