Tuesday, January 29, 2013
Thursday, January 3, 2013
Richard Childress Racing Puts CNC Machining On Fast Track With NC Simulation
Affordable
NCSIMUL cuts hours from first piece production cycle
Richard Childress Racing (RCR), one of the predominant names in NASCAR
Sprint CUP racing, knows a little bit about the value of getting on track and
up to speed quickly. It is part of the organization’s culture. So when its
machine shop, where custom parts are manufactured for RCR race cars, was losing
four to eight hours of machine cycle on critical “first piece” parts, it was a
detriment to that culture of speed.
Rick Grimes, Manufacturing Manager for RCR, said, "We have to turn
parts quickly in this business. We are a week-to-week operation. Our shop is
frequently asked to program a part from scratch and get it out to the machine,
then get the parts made and out to the track before the next race. Naturally,
we are eager to do whatever it takes to reduce the time between creating the
model and having the completed first piece in our hands."
Ironically, to speed things up the shop was in the habit of slowing
processes down to avoid potential crashes that could scrap a part and miss a
deadline. Tedious hours were spent at the CNC machine controllers, meticulously
stepping through first piece part programs, one line at a time, to avoid a
potential cutting tool crash.
Of course, the obvious solution was to use some sort of process
simulation package. RCR's PTC Pro/Engineer software came with a basic
simulation utility that allowed the programmer to view movement of the tool
around the part. However, it did not simulate the path of the tool and holder
in relation to the machine itself or the vices and fixtures set up on the
machine’s table. During product research, the programming team found highly
sophisticated software available to do this, but also discovered that those
complex packages can cost far more than the CNC machine itself. In addition,
learning to use this high-end, complicated simulation software was a
time-consuming proposition. This was not an option for an organization that
must turn new part design and production around in less than a week.
Giant
Step
First piece manufacturing took a giant step forward at RCR in 2010 when
its CAD software reseller, 3HTI, suggested that they take a look at a new
simulation software package called NCSIMUL, developed by Spring Technologies, a
French company that had just established a North American subsidiary organization
headquartered in Cambridge, Massachusetts. NCSIMUL is an affordable yet
comprehensive software solution for simulating, verifying, optimizing, and
reviewing CNC machining programs. It can be used in conjunction with CAD/CAM
software. In the case of RCR, it was PTC Pro/Engineer.
Clifton Kiziah, Manufacturing Engineer at RCR, was assigned the task of
learning and implementing the software.
Training sessions were divided into small, digestible modules that he
was able to fit into his hectic schedule. Total time spent in training took
less than two days and these hours were spread out over several weeks.
He was then ready to apply the software, which is designed to improve
CAM generated CNC manufacturing programs in three ways: First, the software
analyzes the CAM program itself, so that coding errors in the program can be
corrected before the postprocessor generates G-Code that is sent to the
machine. Second, the software analyzes the G-Code itself to see how the program
performs in relation to the part, the machine setup, and the machine itself.
Errors are flagged so that the user can correct the code and eliminate any
potential crashes. Third, the software verifies the part geometry against the
model, based on the toolpaths themselves and a kinemetric model of the specific
machine tool that the part is to be cut on.
Grimes said machine model and machine-specific license for NCSMUL was
part of the purchase price. He said that ensuring that the NCSMUL's machine-
specific features operated flawlessly was a team effort between RCR, machine
tool builder Okuma, and Spring Technologies.
Lost
Time Recaptured
Kiziah said that performing a complete simulation with NCSIMUL takes
about 15 minutes. All of this happens at the PC computer
desktop, so that no machining time is lost while the next CNC manufacturing
program is being analyzed. Grimes said that his shop might be called upon to
manufacture unique first piece parts several times a week. Before the company
installed NCSIMUL, many hours of machining time were lost while painstakingly
slogging through the code. This lost time has now been recaptured.
For example, RCR was called upon to machine a heavily revised Oil Cooler
Valve Body for the Inline Oil Filter Assembly, a critical part of a race engine’s
oiling system. RCR had machined the
original Revision A part several years earlier, but, Revision B had extensive
changes to it. The Valve Body part runs
on the 4-axis Okuma MA-500HB Horizontal Machining center because of its
complexity. There are two operations
with multiple B-axis rotations.
RCR faced some challenges with this new revision. Due to the extreme complexity of the part,
some surfaces had to be partially machined in the first operation and then
completed in the second operation. “Before NCSIMUL, we had no way to program and
simulate the second operation using the stock that remained from the first op”
said Kiziah. NCSIMUL allowed RCR to
accurately know how much stock remained for removal in the second
operation. RCR was even able to export
the Op 1 remaining stock from NCSIMUL for use in Pro/Engineer. Once the second operation was programmed and
posted, both operations were simulated together in NCSIMUL. This was done to verify that all surfaces of
the part had been properly finished without any program errors or collisions
between tooling and fixturing. In the
past, without NCSIMUL, RCR would have had to blindly proof the program out on
the machine. If some surfaces didn’t clean up, the operator and machine would
have had to wait around until the programmer re-worked the program. This would
in turn waste several hours of machine time.
Without NCSIMUL, the original Rev. A 1st piece part took 8
hours to proof out. This time around,
with the power of NCSIMUL, the Rev. B 1st piece part was proofed in
only 4 hours.
Similar savings are accumulating throughout the week, saving time,
reducing costs, and making RCR even more competitive at the track.
For more information on NCSIMUL go to: www.NCSIMUL.com
For more information on RCR go to: www.rcrracing.com
For more information on 3HTI go to: www.3hti.com
For more information on NCSIMUL go to: www.NCSIMUL.com
For more information on RCR go to: www.rcrracing.com
For more information on 3HTI go to: www.3hti.com
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