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Attendees <br>
-------------- <br>
Martin Hardwick, STEP Tools, USA <br>
David Odendahl, Boeing, USA <br>
Rich Morihara, Boeing, USA<br>
Thomas Raun, Iscar, USA <br>
Charles Gilman, GE, USA<br>
Paul Wendorf, AMT/MTConnect, USA<br>
Brian Sides, Okuma, USA<br>
Dan Slansky, ARC (Boeing retired), USA<br>
Parker Sykes, SME (Rolls Royce retired), USA<br>
John Horst, NIST, USA<br>
<br>
Many thanks to OMAC for hosting the meeting and to ARC for
organizing the excellent meeting facilities.<br>
<br>
We discussed how the Advanced Digital Machining Consortium will
deploy 3D models on the shop floor. Actions that can be taken
include the development of CAM translators and the development of an
infrastructure for shop floor program measurement and optimization.
We discussed if the ADMC needs its own laboratories.
STEP-Manufacturing has been a virtual organization for many years,
but running experiments is time consuming. A dedicated facility will
be more efficient but more expensive. A dedicated facility will
allow us to test issues more progressively, and without concern
about changed conditions since the last run of an experiment.<br>
<br>
We discussed the CAM data exchange pilot. The next target is to
rough mill the male and female halves of the mold. We discussed how
to model the machining requirements. We agreed that STEP-NC should
be extended to include a "Simulation Model". This model will show
the types of tool paths computed by an OEM for the operation but in
a non-binding way. The exact requirements will be shown by the CAD
geometry of the TO-BE model. For roughing operations this geometry
will have a generous tolerance budget.<br>
<br>
We discussed the REST architecture for manufacturing models. A
similar architecture has been developed for in-process models at GE.
They use the term stage model to describe the TO-BE state for a
manufacturing operation after a setup has been completed. The
STEP-NC models are more fine grain because they also describe the
state of the part after every workingstep (tool change). GE
encountered problems when they used numbers to describe sequencing
for stage models, but they are a simple solution for workingstep
sequencing. <br>
<br>
We discussed the representation of assemblies. The STEP model for
design assemblies stores one copy of a shared item even though it is
used thousands or millions of times in a large structure. For
manufacturing there are issues with this representation when some of
the copies require special manufacturing operations. For example, a
more precise profile for some of the rivets on an air foil. We
postulated that the REST architecture can allow these details to be
represented as an exception within the REST directory structure
using appropriate naming conventions. The goal is to allow
additional PMI to be defined for just the items in question without
requiring additional data to be defined for all of the other parts.
<br>
<br>
We discussed a demonstration of five axis cutter compensation. The
demonstration will use a STEP-NC simulator to predict the to-be
dimensions of a part from the as-measured dimensions of a tool as
determined by a tool pre-setter. The machined dimensions will then
be confirmed using an on-machine probe, and five axis cutter
compensation will be used to correct for the tool wear and return
the part to the required design tolerances.<br>
<br>
<img src="cid:part1.02000900.02040809@steptools.com" alt=""><br>
<br>
A configuration for the demonstration is shown above. It uses
MT-Connect to communicate the as-measured dimensions of the tool,
and the as-measured dimensions of the part. The machine tool uses
the STEP-NC program and the STEP-NC simulator to determine where the
part should be measured and to compute the appropriate five axis
corrections. The stage model defines the tolerances that must be met
at the end of the operation. The surface on the stage model
determines the direction and the probe determines the size of the
compensations.<br>
<br>
We will hold an industry information day on May 7th and 8th to
solicit participation in the demonstration. The first day will be
held in conjunction with the ISO SC4 meeting in Philadelphia and
will focus on the current and future possibilities for using 3D
standards on the shop floor. The second day will be hosted at NIST,
or another suitable site, and will feature a demonstration of the
results of the CAM data exchange pilot plus a discussion of the
requirements for the 5-axis cutter compensation demonstration. We
will then have the summer months to complete the demonstration in
time for the IMTS show in September.<br>
<br>
Action Items<br>
-----------------<br>
1. STEP Tools to participate in the next MT-Connect TAG meeting
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