3D MCAD - CAE - CAM Engineering/Manufacturing
Defined
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This is a description of the
purpose of these two functions as it pertains to the implementation of 3D
MCAD/CAE/CAM. Definitions 3D MCAD We have for years called anything to do with computer aided design – CAD. But in the case of AutoCAD it was Computer Aided Drawing. So, we started with a word that did not describe what we were doing. How many times have you been in a chat room discussing CAD
and found out you were talking to a fellow that was doing “2D” and you were
talking about “3D” or visa versa. You just sighed. So today we are
discussing 3D MCAD CAE – Computer Aided Engineering. This includes and type of engineering analysis or simulation utilizing a computer.CAM – Computer Aided Manufacturing. This encompasses all of the use of computers in the manufacturing of parts and assemblies including inspection.We will start with engineering. I am writing this for the PLM and MBE people that have
never done any engineering and are now designing systems that engineering is
using.
It the beginning, Engineering drove CAD. 3D CAD was implemented to increase the productivity of making drawings. The purpose of 3D Computervision, Catia and Pro/e was to create drawings from 3D design. In the early 1990's with the introduction of CNC we started delivering the 3D model with the paper prints. It wasn't until the late 1990’s with the release of PDF were we able to email the model and documentation.
Engineering’s only purpose is
to make available concise, 3D MCAD was doing just that
until the late 1990’s. But PLM was introduced at the turn of the century
when the high end MCAD systems moved to the PC. I am not sure that they
looked and decided on MBE and the single file of the PMI due to the
delivering of the paper prints but something drove them to this
non-functional process.
This is a PMI
(Associated Information Document) Both are of the same part.
But you must remember the AID travels with the 3D model. So the supplier has the 3D model available the same as with the PMI. The AID as referenced in the name is not a stand alone document. All the mid-ranged users were familiar with the PDF and started utilizing it instantly. Most of the mid-ranged CAD systems incorporated it and allowed you to print a PDF with multiple sheets directly from the program. There are free programs that can print a PDF they act just like a printer. Of course, all of the mid-range allow you to print incredible 3D PDF and many include the PMI such as ZW3D. The high-end programs
took forever to implement many of these very useful features. IGES and STEP were
the only import or export formats for both Pro/e and Catia for years and even then,
they were optional. Even after they moved to the PC. The introduction of MBE is
where the PLM folks started driving engineering. Boeing, which had the most
streamlined and productive engineering system and standards in the world
actually let Dassault with their new Catia 5 and PLM to take over their
engineering. This move was proven instantly fatal with Catia 4
and Catia 5 being completely incompatible! This one fact cannot be overlooked. It
shows an incredible lack of understanding of the purpose of engineering. That put Boeing on a downward path and now Engineers
were struggling to utilize a very convoluted system. Now, I have to tell you small companies did not fall
into this trap, only those that were stuck with the high-end systems. As
they moved to the PC they still were very top heavy and took years to
implement the productive enhancements of the mid-range products. The mid-range products designed circles around these
high-end systems and still do. Good God, Joe, what the hell has this got to do with
Engineering and Manufacturing? As PLM took over the management of engineering the
solutions they gave engineering were not working. Starting with utilizing
the model as the design authority. They started adding Band-Aid after
Band-Aid trying to make this work. Suppliers just worked around most of the
silly, not thought through requirements.
Ooops, did I accidentally reference manufacturing?? Yes, I did. We are now defining engineering documentation driven by
the PLM folks. The draftsmen were being let go and replaced by degreed
engineers that have no experience with engineering documentation. Ah, any ties to the past knowledge to engineering
documentation was soon gone. The PLM folks were now the experts. This is where things get a bit dicey. Somewhere along the line the PLM folks thought that
engineers were involved in manufacturing and they thought that the
documentation could be used directly in manufacturing. This is just not how manufacturing works. Engineering works in the abstract. Even though today the 3D model makes us think our designs are real, they are nothing more than cartoons. We still have to give the instructions on how to make and assembly the parts in a concise, complete and unambiguous format.
This is the point the PLM folks will never
understand. I see this fellow pushing a
“live” BOM 3rd party program. What in the world is the problem he
is trying to solve? I have asked him a few pointed questions. He said it gives
purchasing live data to get ahead of the design. I chuckled at his ignorance
of the engineering design process. We have a multitude of 3rd
party programs for the MCAD products. You spend thousands on Pro/e, Catia
and NX and you have to buy 3rd product solutions? Even the mid-ranged programs
have a myriad of 3rd party programs to make the programs more
effective. The most incredibly 3rd
party program is the Quoting program I discuss in this article.
The PMI is in format that has no dimensions
beside a few limited dimensions. Since you have no idea what size the part
is you have to have a 3rd party or the native program that allows you to dimension it. So what has all this streamlined engineering defined by those that have never done and engineering accomplished? You just have to go WTF. Is there no one with any
knowledge even involved? Okay, Okay, I know, I know I am still beating this
fricking drum, and I suppose I will until someone wakes up.
Engineering does the design. There are many things
that have to be established before engineering starts work. You have the
Industrial designers come up with concepts. When that is complete enter the
configuration management. Working with engineering they define the
requirements. Engineering sets up the groups to get the process in place. Imagine how Elon Musk set up Tesla. Can you imagine?
Let’s build a new automobile. He hired engineering expertise in many
different groups, power train, chassis, interior, glass, electronic, etc.
and went to work designing the new Tesla. Now engineering would build prototypes of most of
the not purchased components. Prototyping is not manufacturing. It is
assuring the design is feasible. Now, manufacturing may look at the work to
establish a process. Now the engineering is not done until the
documentation is done. PLM folks think that his can be a live link to
manufacturing. They live in a pipe dream. Luckily the suppliers are much
smarter than the MSMEs, PHDs and Infotech geniuses. They have to “MAKE”
parts. They moved from the abstracts to reality. Now to manufacturing. Most of the larger companies have outside suppliers
that make their parts. Now, these suppliers are always changing, there are
large, not so large and mom and pop suppliers. If a company does have inside manufacturing then
this MBE system could work since it required management on both sides. If
not, it is Murphy’s playground. If you have to ask who Murphy is. Pack your stuff
and leave today. Engineering delivers the documentation. This
includes the 3D model and any associative information. We do not care what
format. It is delivered to the supplier as a file. At this time, the engineering is done and the native CAD data and documentation should be archived and easily accessible. There is no released documentation that is not archived. There is no such thing as current engineering documentation. It is archived and available forever. While working for Boeing, I checked out the original linen drawing for the KC-135 for the first time since it was created in the 1950's. Purchasing, marketing, Tech pubs, even engineering should use this released archived data. Actually it is one engineering's main purpose to release the engineering documentation to the archives. If we are smart the engineering deliverable will be
outside the native CAD system in the form of a released document. That
documentation will now be the only official documentation used by any other
department. I explain the optimum document controls system in these articles.
This is where engineering parts ways with
manufacturing. Engineering Documentation Today. The documentation should be concise, complete and
unambiguous. All of the parts are ordered. They start coming back to the company. Boeing demands
inspection by the suppliers. This is a bit short sighted since parts can
actually change between order and delivery. So, any parts that come in
should be inspected to the latest engineering release on delivery. At
least the mating features. These parts are logged in! No, not by engineering
but by manufacturing. They are experts in assembly. They will have planning
orders and these parts will already be in the program. They will be
delivered to the appropriate process and be assembled. Rarely is engineering even involved. Maybe at the
first article. But the manufacturing people are experts in their field and
know what needs to be done. This is reality and not abstract. Nothing makes an engineer or designer (in my case)
feel more fulfilled than to see their designs become reality. I have to tell you it is that simple. I have found that someone came up with a quite
bizarre acronym. DFM (Design for Manufacturability) I have been a draftsman for over 50 years and I was
shocked to see this. Draftsmen were responsible for most of the form, fit
and function design of every aircraft ever built and every drawing came out
of he drafting group was designed for manufacturability. I cannot imagine a group of people that had to come
up with his acronym. I will tell you they were not draftsman. We had
engineers that oversaw the design process, design draftsman developing the
form, fit and function design, draftsman creating the drawings, checkers
reviewing the drawings for both design and drawing correctness, reviewed and
signed off by the lead engineer. Now you tell me which one of those professionals had
to be told to design for manufacturability. This one acronym
alone exposes the lack of
For more information or to download IronCAD or ZW3D Joe Brouwer 206-842-0360 |