Re: Comparison of Cadd

At 07:37 AM 7/27/01 -0700, it was written:

> >Autocad is the industry standard and would probably give your lad more
> >options for future employment<
>
>True, true.
>But what an awful, counterintuitive, unfriendly program to have to learn!!!
>For my money, the way of the future is solid modelling.
>That means either Pro E or Solidworks. (There are others, but these two have
>dominant market share and are likely to be the de-facto standards of the
>future)
>
>The advantages of solid modelling for any kind of design are many, and most
>serious designers are going this route in order to tap into those benefits.
>
>An additional benefit of solid modellers, is that the skill set learned with
>one program is far more transferable to another modelling package than the
>skills learned with a conventional drafting package.
>
>With solids, the model construction strategy is the bulk of the skill, and
>this is useful to know for any other solid modeller.
>
>With a program like Autocad, the commands and how to manipulate them
>efficiently is a far bigger part of what you learn, so a change of CAD
>package puts you much farther back (to square one) than it does if you know
>how to model in solids.

I believe there are many small firms still using 2D packages, of which
AutoCAD is predominant. Many larger companies are moving or have moved to
solid modeling though. It still depends on where you end up working. :-)

In Mechanical Engineering Technology at Oregon Institute of Technology we
require our students to take drafing/modling related courses as 1) Manual
(board) Drafting, 2) 2D and wire frame modeling (AutoCAD), 4) Geometric
Dimensioning and Tolerancing, 3) Solid Modeling (I-Deas), 4) Applied FEA
(I-Deas). We also offer an elective CAD course using Pro-E which most
students take. The reason we use I-Deas rather than Pro-E is mostly
economic, I-Deas gives a better and more complete educational site license
than Pro-E. Pro-E is more widely used and I think it still has the largest
share of the solid modeling market?

As to each 2D system being different so the learning doesn't carry over
well from one to the other, but that solid modeling skills do. In saying
this I think you are taking for granted the basic 2D drafting
skills. Things like: what is a three view drawing, what's this dotted line
for, which view a dimension should go on, etc. This is second nature to
most on this list, but they are skills which need to be learned and do
carry over to any 2D package. In the same way the knowledge of how to go
about building a solid model carry over from package to package. Thus, at
OIT, we aren't greatly concerned which packages we teach with, the basic
knowledge is transferable. But students, or others looking for a similar
career, should obtain these underlying skills.

>Not only that; a solid model gives you immediate access to a physical model
>via stereolithography, whereas a CAD drawing gives you nothing in that
>regard, and stereolith is a godsend for those who need a physical model but
>don't have the skills to make one.

Overall solid modeling is more useful to a design effort. It better shows
what the parts look like, can be matched up to show interferences, and can
facilitate further analysis (like FEA). Parts can be made directly from
the solid model also. Rapid prototyping (stereolithography) can be used
directly but also tool paths can be generated from the solid. Some
companies are making the computer solid model the definition and record of
the part. For this they have to add information of tolerances, finish,
material, etc, not to mention requiring sub-contractors to understand and
quote jobs using the solid model data base.

>Last I checked, Solidworks is not much more expensive than Autocad; and you
>have to consider that you are investing in your son's EDUCATION!!!
>
>Why hobble him with a dinosaur, when the cutting edge is available.

It will advance ones career when working with mechanical drawings to
understand both view drawings (2D) and solid modeling. I'd suggest AutoCAD
or one of its clones for learning 2D. There is a good chance the specific
knowledge of AutoCAD will be of use as it is still the most widely used 2D
package. How about AutoCAD-lite, does it still exist, or a clone? To
learn solid modeling the best would be Pro-E but the commercial package is
too expensive. Both Pro-E and I-Deas have educational versions for a few
hundred dollars though. These packages are available to full time
students. I don't have knowledge of other solids packages which might be
applicable.

Remember, the question was "for my son to learn to further his
career". For personal use the answer is different, use what you want 'cuz
it's a hobby and we don't have to interface with others. :-) I'm
personally using CadKey and am the proud new owner of Vector CAD/CAM. So
far Vector is a great solution for my personal CAM, it is very oriented to
CNC. I also want to learn more of generating tool paths from solid
models. I have the advantage of access through work (OIT) to Pro-E,
I-Deas, Master CAM and Feature CAM.

Lets see now, I want to: learn EMC, finish up and tune X/Y on my mill
retrofit, add Z to my mill, migrate from Windows to linux, install a
wireless Internet link, restore a 1955 Shasta trailer, make enough $ to
eat, and may more not at the top of the list. I just need the time. :-(

>Comments anyone??

Sorry, no time for comments. :-)

Hugh Currin
Klamath Falls, OR