[step-manufacturing] Minutes of December 2nd Conference Call

[Martin Hardwick]

Attendees
Martin Hardwick, STEP Tools, USA
David Loffredo, STEP Tools, USA
Vincent Marchini, Ameritech, USA
Mikael Hedlind, KTH, Sweden
Qiuling Huang, KTH, Sweden
Yujiang Li, KTH Sweden
Fred Proctor, NIST, USA
Bengt Olsson, Sandvik, Sweden
Alain Brail, Airbus (retired), France
Arnaud KREMER,  Ecole Nationale Supérieure d'Arts et Métiers, France

Apologies for absence
David Odendahl, Boeing, USA
Sid Venkatesh, Boeing, USA

NIST is holding a model based engineering workshop from December 12th to 
December 16th and the plans for implementing a pilot CAM data exchange 
will be discussed.

http://www.nist.gov/el/msid/tdpsummit_2011.cfm

KTH gave a demonstration of cutting tool data exchange using AP-242 
files enhanced with ISO 13399 semantics. They exported a file from NX. 
Imported the file into ST-Machine and a custom application. Changed the 
tool length in the custom application and read the new data back into NX.

ftp://ftp.steptools.com/private/CAM_exchange/KTH_cutting_tool_data_exchange_ISO13399_enhanced_AP242.pdf
ftp://ftp.steptools.com/private/CAM_exchange/KTH_ISO13399_enhanced_AP242_NX_export.stp

We discussed the export of kinematics using AP-242. A general feature is 
being used to define the linkage points between the cutting tool and the 
spindle and between the fixture/part and the machine tool bed. However, 
the general feature is being described using a new data pattern because 
of a new restriction in AP-242 that only allows each feature or 
tolerance to contain one face. This constraint was imposed by one of the 
modules deep within the the STEP infrastructure and came about because, 
for highly theoretical reasons, the owner of the module thought it would 
be a good idea. The cost to add the rule was 5 minutes but the 
consequence for the rest of STEP is deeply disturbing .

For example, the fishead has tolerances defined on its eye and on 
several walls. The cylinder that defines the eye is made up of two faces 
because this is how many CAD systems model holes and some walls are 
defined by two faces divided by a rib. In practice many features and 
tolerances contain multiple faces and the new rule is not practical. A 
protest has been sent by STEP Tools to the US STEP community, and KTH 
will do the same for the EU STEP community.

A new version of the Presentation XML was demonstrated using the Firefox 
and Chrome browsers. The XML has been augmented to include tool path and 
cutting tool data.

A recording of this conference call is on the ftp site.  The next 
conference call will be at the regular times on Friday December 16.

ftp://ftp.steptools.com/private/Undecided/stepmanuf_telecon_20111202.wmv

Martin Hardwick
Team Leader