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Long list of stuff here (all the stuff I didn't have time to fit into
the first 3 reports). Usually trying to catch up a couple of weeks
later is a chore, but, just looking at notes and handouts, I'm easily
back in the spirit of the conference, just a great place to meet
people and get information.
And here are some techniques for checking your results, checking the
working part you've created against the original imported reference
part:
And here's the managing references list. Looks like a typical
engineering situation, no perfect solution, compromises everywhere:
Patterning the Impossible
This popular session, by Paul Gear from Advanced Parametric Concepts,
was given Tuesday and repeated Wednesday, and got the prize for the
best user presentation. Paul showed how to control dimensional patterns
using simple relations. If you want to automate using Pro/Program you
can do that, but the foundation of simple relations is easier, you
don't need Pro/Program.
Paul has a couple of parts right on his Web site, www.advparametric.com,
that you can download to check out relational patterns. Name of the
file to download is profiles_examples.zip.
My example below is based on the rectangular part.
Using the advanced technology of ASCII graphics, here are some of the
typical patterns you can create using simple relations. In each case,
there's just one initial hole, and just one pattern based on that hole.
Total of two features for each of these examples, one hole and one
relational pattern:
O O O O O
O O
O O
O O O O O
or
O
O O
O O O
O O O O
O O O O O
or
O O O
O O O O
O O O O O
O O O O
O O O
Take that first example, how do you do this? Say, you start in the
lower left corner, with hole no. 0, you can go around the
pattern in an anti-clockwise direction.:
11 10 9 8 7
12 6
13 5
0 1 2 3 4
Using Pattern Relations, you can create two equations, one controlling
the horizontal movement of your hole, and the other the vertical
movement, as you take your hole on a walk around the rectangle.
For each hole in turn, the two equations are evaluated, and the hole
is placed at the resulting location.
Why start with 0? That's because programmers are different from the
rest of us, they always start with 0, they don't start with 1 like us.
Keep in mind here you want 14 holes total, numbered 0 to 13. Helpful
probably to do a sketch before any relational pattern work.
So, now you can start creating a relational pattern. Put a hole 0.5
units diameter in the middle of a plate which is at least 10 units
on a side (make the plate plenty big, so if you make a mistake and
put holes in the wrong direction, they'll still end up on the plate).
Then from the menu:
Feature > Pattern > Pick (select your hole) > General > Done
Andy emphasized that with any pattern, it's worth creating it as a General
pattern first, the most robust form of pattern. After you're sure it
works ok, you can always redefine it as a Identical or Varying pattern
for faster regeneration. Then:
Relation (skip the default Value) > <select horiz dim> > Edit
Now you're plunged into a plain old text editor, not Pro/Table at all.
This isn't the table method of defining a pattern. But remember to quit
out of the text editor after saving your work there, if you leave the
editor window open you won't be able to do anything else in Pro/E.
And you get this intimidating greeting:
/* Enter relations using the following symbols:
/* memb_v - relation driven resultant dimension in this specific direction
/* memb_i - relation driven increment in this specific direction
/* lead_v - leader value (dimension selected to determine direction)
/* idx1 - pattern instance index in the first direction
/* idx2 - pattern instance index in the second direction
/* DO NOT USE memb_v AND memb_i IN THE SAME RELATION
/*-------------------------------------------------------------------
As Andy said, that alone has probably deterred most people from using
relational patterns.
But all you need know here is two symbols, questionable how much you'd
use the other symbols. The two symbols are:
- memb_i the amount you want to increase or decrease the dimension
you just selected for a particular hole (the horizontal dimension
if you're working on the equation for the horizontal dimension, or
the vertical dimension if you're working on that equation)
- idx1: the number of the particular hole. First hole is 0, second hole
is 1, hole at lower right corner is 4, hole at upper right corner
is 7, and so forth.
We're looking for an equation to control horizontal motion around the
rectangle, so, here it is. I've put in my comment lines with a /*, just
like the comment lines above, so they won't interfere with the program.
/* horizontal dimension equation
/* this equation will run for each hole, starting from no. 0, going from
/* no. 1 to no. 14. Equation will run first for hole no. 1, place that
/* hole. Then run again for hole no. 2, place that hole. And so on until
/* it gets to the last hole in the number of holes you specify, here
/* 14 holes. All holes are 1 unit apart.
/* start off incrementing horizontal dimension by 1 for each hole
memb_i = 1
/* after hole no. 4, lower right corner, stop incrementing that
/* hor dimension at all, let it stay fixed while the second vertical
/* dimension equation drives up the right edge (you'll create that
/* equation after this one, this equation is just horizontal motion)
if idx1 > 4
memb_i = 0
endif
/* after hole no. 7, upper right corner, now start decrementing the
/* hor dim for each hole by 1, to move them back to the left side
if idx1 > 7
memb_i = -1
endif
/* and finally, after hole no. 11, upper left corner, stop changing
/* the hor dim once more, leave it fixed while that second vertical
/* dimension equation brings the hole back down
if idx1 > 11
memb_i = 0
endif
And now you can go on to do the second equation, to control vertical
dimensions of each hole in the pattern:
Done > Relation > (select vertical dim) > Edit
Here's what you'd type in there, for the vertical equation:
/* vertical dimension equation
/* just like the horizontal dimension equation, this equation runs
/* over and over, once for each hole, starting with creating hole no. 1
/* and finishing with creating hole no. 14
/* start off with vertical dimension fixed, not changing
memb_i = 0
/* after hole no. 4, lower right corner, start incrementing vertical
/* dimension by 1 for each hole
if idx1 > 4
memb_i = 1
endif
/* after hole no. 7, upper right corner, fix the vertical dimension
/* so it doesn't change, no increment
if idx1 > 7
memb_i = 0
endif
/* and after hole no. 11, upper left corner, reduce the vertical
/* dimension by 1 for each hole to finish the pattern.
if idx1 > 11
memb_i = -1
endif
When you develop a pair of equations (hor dim and vert dim) for a
particular hole pattern, worth saving them as separate text files,
to use again on other parts, just cut and paste to reuse.
After entering both equations, you get this final question, just
like for any pattern:
Enter TOTAL number of instances in this direction (including original):
But remember that even though you're going in different directions,
Pro/E figures only one direction, controlled by two dimensions. So
enter here the total number of instances in your entire pattern (in
this case, 14 holes).
And that's it. Your entire pattern will be generated from those two
equations, for the total number of holes you entered.
To edit a relational pattern, after you've saved the part, just
go back to the Part menu and do this:
Relations > Pattern Rel > (pick the pattern) > (pick a dimension)
Since you're really only going in one direction on this pattern, the
Second Dir choice will be greyed out, and you'll have only 2 Driver
Dims to pick. After you pick one dimension, then do
Edit Rel
to get back into that text editor to edit that equation.
Engineering Management at Airbus
Bob Landeg from Airbus, the European rival to Boeing in the airliner
market, gave a very interesting talk. Bob's title there is Manager of
Concurrent Engineering. He started off by saying they use
Computervision CADDS5 for design, which he said Dick Harrison would not
like, but he said they are moving to Windchill for configuration
management, which Dick probably would like. Airbus isn't using CADDS5
because of some ancient legacy constraints, instead they held an open
benchmark back in 1996 for a new mech. design system, and CADDS5
trounced the competition, including Pro/E, for their needs.
Although Airbus is a European company, the 12 largest subcontractors
are in the US. And as probably typical at the largest manufacturing
companies, Bob said they probably have all the software packages in the
known world, including the top 5 CAD systems, to work with all their
contractors and partners. They tried to build their own custom solid
modeling system in 1995, based on Parasolids (like some other large
manufacturing companies), but after spending $4 million only gained 4
users, a cost of $1 million per seat. Bob said in retrospect they could
have just dropped the project at the beginning, given each user a
Ferrari, and come out ahead.
Airbus is right now this year on track to become an independent single
company, but so far it's been a consortium of 4 separate aerospace
companies from the UK, France, Germany, and Spain (Aerospatiale,
British Aerospace, DaimlerChrysler Aerospace, and CASA from Spain).
There's an obvious problem with trying to develop common tools,
methods, and processes. Back in 1996 (at the time of that CAD
benchmark) they set a goal of implementing concurrent engineering
methodologies, remembering that 80% to 90% of such change programs
fail.
They are now doing same day upgrades of engineering tools, including
process changes, for over 600 people. They require all related software
versions to be delivered 3 months in advance, for testing independently
and together. The first of these upgrades took two weeks to finish and
sort out the confusion, but Bob did keep his job. After the most recent
Airbus wide upgrade, Bob got a call from one user asking when the
upgrade was going to happen, who couldn't believe it had taken place so
easily.
Airbus has integrated KBE, a knowledge engineering tool, with CADDS5
and NASTRAN to design complex structures like wing ribs. That's a big
investment in automation, but they've seen 30 man years shrink to as
little as 6 days, to make a sudden overall change to a wing. They used
to use as many as 2500 drawing sheets to document a rib, now they can
do that with 1 CADDS5 solid model and 5 sheets (not quite paperless).
They used to have an engineering team spend 6 months to fix several
hundred problems on a new rib set for a new wing, but on the last set
they had only 1 problem recorded.
All these CAD sucesses still leave a job to do in configuration
management. Airbus is looking to implement Windchill as a enterprise
product data management system, as a single source throughout the
company of product and process data. Windchill will be replacing a
1970's era configuration management system (an example of how CAD
systems may change slowly at a company, but PDM systems usually change
even more slowly, a different time scale entirely).
Florida travel notes (bonus)
Last year's travel notes bonus was all about Waxahachie, a small
historic town south of Dallas. This year's notes are about the Florida
northeast coast.
I have to admit, growing up in New York and New Jersey, my impression of
Florida at a distance was flat and dull and boring. But visiting it now
there seems to be always something new to find in Florida. Here are
travel notes from this trip:
Flagler Beach
Flagler Beach is a small town on the Atlantic Coast of 3000 people,
that's all. And quite unlike coastal development in California. Every
single motel and restaurant and gas station in Flagler Beach is right
on the ocean, all of them about 200 feet from the surf. Very
democratic, equal, unlike California, where the price of your room is
measured by the distance from the surf.
Pelicans fly in formation right down the center line of the main street
in Flagler Beach, haven't seen that anywhere in California.
Moonrise over the Ocean
On the West coast, we can't see the moon rise over the ocean, because
here the moon rises over land, in the direction of Nevada. To see the
moon rise over the ocean, you have to go to the East coast. Walking
along the beach on my first night, wriggling toes in the warm water, I
saw the full moon rise up over the Atlantic. Up through layers of
clouds, alternately visible and hidden, until finally it broke clear
into the upper sky. While on the landward side massive thunderclouds
were lit up from within by displays of aerial lightning. Somehow the
typical California sunset over the ocean seemed perhaps dull.
Washington Oaks State Gardens
Florida doesn't have just State Parks, but also State Gardens. I
passed by one, Washington Oaks State Gardens, on the way north from
Flagler Beach. Stopped by out of curiosity, then spent almost 2 hours
just passing time there. One of the most relaxing places I've known.
Small, not very large, no fancy horticulture, but just paths winding
around with ponds and simple fountains, and very comfortable wooden
chairs at each bend. Was hard to leave, got out of one chair just to
sink into another.
St. Augustine
You know the usual welcome sign at the entrance to a city? Greetings,
plus when the city was founded. At St. Augustine it modestly reads:
Welcome to St. Augustine
Founded 1565
True, oldest town in the US, over 400 years old. It was burned down
regularly in the early years, so not much remains of those buildings.
But there are plenty of businesses and residences in the 200 to 300
year old category. They did have to be rebuilt and renovated
regularly, otherwise they wouldn't be here today, but they are an
authentic hodgepodge of styles. Some more Caribbean, some more New
England, depending on who was in power in St. Augustine at the time
(the Spaniards, or the English, or the Americans).
There are the usual T-shirt shops in some of the older buildings, and
other tourist trap places. But down at the end of the town is a real
historical relic, which anchors the whole place firmly in time, the
Castillo de San Marcos. An entire stone fortress, on the very best
Spanish 17th century principles, with bastions and moat and drawbridge
and sheer tons of stone. There's a gift shop on the first floor, but
nothing could much alter the impact of this fortress.
Travel Tip
In Outdoor World in Orlando, a sporting goods store 600 feet long with
a 5 story high central aisle, I found a stuffed colorful trout fish
pillow 5 feet long (sort of on the same scale as the store). Wife has
always liked stuffed fish pillows, we have a few around the house. So I
got the 5 foot long one, wondering though how I'd get it across the
country.
No problem at all transporting it. As soon as I entered the airport,
carrying my 5 foot stuffed trout pillow under my arm, people started
laughing, and people kept laughing all the way. Three ticket agents
standing side by side cracked up, then their manager came out from a
rear room to see, and he cracked up too. Maintenance people couldn't
help laughing, so did any security staff I passed. Generally, the fish
(or, me carrying the fish, to be more exact) made people laugh within a
radius of 150 feet in any direction. Instant merriment all around.
My tip here is, anytime you want to brighten up a plane trip, and
brighten up the lives of your fellow passengers and the crew and the
airport staff and everyone else in sight, take along a 5 foot long
stuffed trout pillow, it works.