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Attendees<br>
---------------<br>
Alain Brail, AlBavis<br>
Martin Hardwick, STEP Tools<br>
David Loffredo, STEP Tools<br>
Mikael Hedlind, KTH<br>
David Odendahl, Boeing<br>
Bengt Olsson, Sandvik<br>
Fred Proctor, NIST<br>
Leon Xu, Boeing<br>
Larry Maggiano, Mitutoyo<br>
Ian Stroud, EPFL<br>
Stephen Newman, University of Bath<br>
Brian Kindilien, CCAT<br>
Chris Pfeifer, CCAT<br>
Sid Venkatesh, Boeing<br><br>
<br>
Apologies for Absense<br>
--------------------------------<br>
Aydin Nassehi, University of Bath<br>
Magnus Lundgren, KTH<br>
Bob Ericksson, Pratt & Whitney<br><br>
The latest version of the Moldy data includes flute count and spindle
power data. We discussed how to use this data to generate appropriate
feeds and speeds for each CNC that needs to machine the part. The
following formulas have been suggested by Sandvik<br><br>
<font size=2>Parameters to adjust:</font> <br>
<font size=2> flute count -goal is to
maintain chip load by adjusting speed and feed.</font> <br>
<font size=2> speed&feed override
-goal is to maintain chip load by adjusting speed <u>and</u> feed</font>
<br>
<font size=2> feed override -goal is to
change chip load by adjusting the feed</font> <br><br>
<font size=2>Machine tool limitations:</font> <br>
<font size=2> speed max -goal is to
maintain chip load by adjusting speed and feed down to speed max</font>
<br>
<font size=2> feed max --goal is to
maintain chip load by adjusting speed and feed down to feed max</font>
<br><br>
<font size=2>Logic</font> <br>
<font size=2>=====</font> <br><br>
<font size=2>Change of flute count:</font> <br>
<font size=2> speed = speed_old * (flute_new /
flute_old)</font> <br>
<font size=2> feed = feed_old * (flute_new /
flute_old)</font> <br>
<font size=2> run logic for changed machine tool
limitations</font> <br><br>
<font size=2>Change of speed&feed override:</font> <br>
<font size=2> speed = speed_old *
overr_speed&feed</font> <br>
<font size=2> feed = feed_old
*overr_speed&feed</font> <br>
<font size=2> run logic for changed machine tool
limitations</font> <br><br>
<font size=2>Change of feed override:</font> <br>
<font size=2> feed = feed_old * overr_feed</font>
<br>
<font size=2> run logic for changed machine tool
limitations</font> <br><br>
<font size=2>Changed machine tool limitations:</font> <br>
<font size=2> if speed > speed_max then</font>
<br>
<font size=2> speed =
speed_max</font> <br>
<font size=2> feed =
feed_old * (speed_max / speed_old)</font> <br>
<font size=2> if feed > feed_max then</font>
<br>
<font size=2> feed =
feed_max</font> <br>
<font size=2> speed =
speed_old * (feed_max / feed_old)</font> <br><br>
The data generated by these algorithms needs to be saved in a file that
is specific to the use of this STEP-NC program on this machine.<br><br>
A new version of the Boxy part has been generated by KTH. This version
contains extensive in-process CAD models showing the "state" of
the part before and after each workingstep and showing the volumes
removed in each workingstep.<br><br>
We discussed two sets of challenges. The first challenge is how to
document the two setup's in one STEP-NC file.<br>
1. The simple STEP-NC solution is to put each setup in a different STEP
file. The better solution is to model both setups in the same file. There
is some support for multiple setip's in the STEP-NC DLL. A new version of
the STEP-NC data needs to be created with these setup's to verify the
functionality.<br>
2. Tolerances need to be defined for the in-process models so that the
system can check the configuration of the second set-up before machining
begins and possibly check other models during the machining as
well.<br><br>
The second challenge is how to improve the accuracy of the machining
simulations.<br>
1. The simulator always put the part in the middle of the table, but in
practice most CNC engineers would put the part off-center to avoid
singularities.<br>
2. A simulation of the part on the Trunnion machine shows that the
default axis configuration is a poor choice. Post processors allow the
user to select the "front" or "back" of the axis.
Similar constructs are available in STEP-NC and we need to test
them.<br><br>
We discussed meeting logistics. We decided that SC4 T24 should meet for
two days - Thursday September 24 and Friday September 25th with the
meeting on the 25th possibly finishing early to allow for plane
connections. The demonstrations will be given on the first day. Stephen
Newman will produce a list of the equipment available for a live demo.
The second day will be used for planning follow-on meetings and
activities. Martin Hardwick will produce an agenda. <br><br>
The agenda for the SC1 meeting on Monday, Tuesday and Wednesday is being
developed by Ian Stroud. The Wednesday agenda will focus on the machine
tool model and will be a joint SC1/SC4 meeting. Martin Hardwick and Ian
Stroud will coordinate the agenda for this part of the meeting.<br><br>
The T24 meeting on Thursday and Friday will be open to all visitors.
Previous meetings have included representatives from CAD, CAM, CNC and
Machine Tool vendor companies. Overseas visitors are always welcome.
There are no nationality restrictions for this meeting.<br><br>
The next conference call will be at the regular times on Wednesday July
15.<br><br>
A WMV archive of the meeting is at
<a href="ftp://ftp.steptools.com/private/Bath/stepmanuf_telecon_20090603.wmv" eudora="autourl">
ftp://ftp.steptools.com/private/Bath/stepmanuf_telecon_20090603.wmv<br>
<br>
</a>Action items<br>
------------------<br>
1. Boeing to test the new feed-speed generation by changing
the flute count of a tool and machining a Moldy part.<br>
2. STEP Tools to investigate creating a STEP file for Boxy
with two setup's.<br>
3. KTH to define tolerances for the TO-BE model of setup 1
which is also the AS-IS of setup 2.<br>
4. David Odendahl to investigate STEP-NC method for
restricting axes.<br>
5. Stephen Newman to develop list of equipment at Bath that
can be used for a live demonstration<br>
6. Ian Stroud to make agenda for SC1 meeting<br>
7. Martin Hardwick to make agenda for SC4 meeting<br>
8. Ian and Martin to agree on agenda for joint meeting.<br>
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