 The Modig Profileline for aircraft
extrusion longeron and stringer machining has become very popular among the world leading
aircraft manufacturers. Companies like Boeing, SAAB, Airbus, Raytheon, and some
subcontractors have already invested in a number of machines.
The machine is very cost effective, depending on the following
examples:
The investment is relatively low.
The machine provides high productivity (one company reduced their
lead-times from three weeks to three hours).
The system floor space is small yet has the capacity for aluminum
extrusions up to approximately 40’.
The fixturing and tooling costs are small.
The machine can be built to specification requirements. Machines have
been installed with 20,000 and 45,000 maximum rpm spindles. Additionally, the system is
available with either Heidenhain, Siemens, or GE/Fanuc CNC controllers.
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 The
Modig Profileline has a unique design with two rotary tables as the workpieces holding
fixtures. The left rotary table is attached to the X-axis and the right rotary table moves
on a U-axis (moves parallel to and is mounted on top of the X-axis).
This arrangement provides:
While moving the X-axis the two rotary tables move parallel to each
other.
The right rotary can be moved left or right relative to the left
rotary table (closer or farther away for maximum workpiece support).
With the U-axis, the workpiece can be shuttled through the machine in
both directions with high accuracy, regardless if the final part is 1" long or
40’.
The rotation of the rotary tables is performed by two servo motors
connected in the control as a gantry function (they work in tandem).
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 The
clamping of the workpiece is very simple with a three jaw chuck arrangement: one fixed
reference jaw and two moving clamping jaws in each chuck. This simple setup makes it easy
to design custom jaws to fit a wide range of extrusion profiles. The jaws are clamped by
hydraulics. The jaws attach to the chuck on a precision slide and lock
in place with a spring-loaded button. This provides fast changeovers from one workpiece to
another with minimum of hand tools and time.
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 One type
of jaw is equipped with rollers which, when using a low hydraulic clamping pressure, makes
it possible to pull or push the workpiece through the chuck while machining maintaining
the reference and accuracy. When machining with roller jaws, the
spindle can be positioned very close to the left rotary table while the right rotary table
pulls or pushes the workpiece past the cutting tool. This method provides good rigidity
for machining.
The roller jaws can also be custom designed to fit different extrusion
profiles.
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 Modig
also provides a solution to machine joggled parts (the joggle machined into the workpiece
during the processing of the workpiece). To compensate for the reference surface changing
when the part is joggled, the reference jaw can be moved from its original position. The movement is controlled by an adjustment arm, assembled to the machine
base, which connects to the jaw holder of the reference jaw. The cross table (Y-axis) is
moved in or out to position the reference jaw to the required position relative to the
part reference. After the jaw is set, the adjustment arm is retracted.
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 The
system can be either fully manual or fully automatically loaded. An example of the
available options is an automatic workpiece magazine as shown above. The operator loads
the magazine as extrusions are used; the machine automatically picks up the extrusions,
feeds them into the machine, and processes the parts. The magazine can
store 10 extrusions at a time allowing unmanned processi ng of parts for a length of time.
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 With reference to the previous
page for optional loading solutions, this photo shows a small parts catcher basket than
can automatically unload small parts are they are completed. This parts catcher is mounted
to the back of the right rotary table. This catcher can handle parts from 1" to
8". Modig also has automatic unloading systems to handle finished parts up to
40’ long. |
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