[step-manufacturing] Minutes for the meetings on Feb 13 & 14

[Martin Hardwick]

Attendees
--------------
Martin Hardwick, STEP Tools, USA
David Odendahl, Boeing, USA
Rich Morihara, Boeing, USA
Thomas Raun, Iscar, USA
Charles Gilman, GE, USA
Paul Wendorf, AMT/MTConnect, USA
Brian Sides, Okuma, USA
Dan Slansky, ARC (Boeing retired), USA
Parker Sykes, SME (Rolls Royce retired), USA
John Horst, NIST, USA

Many thanks to OMAC for hosting the meeting and to ARC for organizing 
the excellent meeting facilities.

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.

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.

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.

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.

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.



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.

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.

Action Items
-----------------
1. STEP Tools to participate in the next MT-Connect TAG meeting
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.steptools.com/pipermail/step-manufacturing/attachments/20140219/f3c10b9b/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: image/png
Size: 14809 bytes
Desc: not available
URL: <http://lists.steptools.com/pipermail/step-manufacturing/attachments/20140219/f3c10b9b/attachment.png>