On Sep 27, 6:16 pm, Dana M. Hague
d(dash)m(dash)hague(at)comcast(dot)net wrote:
A fully 3D program is, IMHO, a must for any kind of design, anything
else is silly. A parametric modeler, however (like SWX and many
others) can be very cumbersome to use... and I've used a lot of them
over the years. Yes, if the design constraints are set up correctly
from the start, minor changes can be ridiculously easy... but if not,
or if you don't have a clear idea of where you're going from the
start, you can find yourself boxed into a corner and have to start
from scratch.

Personally, I prefer a pure geometry based modeler. Simple
dimensional changes affecting many components may take longer, but
it's far easier to make large sweeping changes if necessary, or switch
to an alternate design approach. Most of my work nowadays is large
machine design (though my degree is in aero engineering), for which I
use KeyCreator (formerly Cadkey). Same price range as SWX, though,
which I don't define as "cheap".

I read all the responses and looked around the 'Net, and it seems that
SolidWorks, if not what I'm looking for, is create by people who had
the mindset I was looking for.

But now I am confused. I thought parametric modeling was good.

I program computers from time to time, and being able to change the
structure of a component and have everything that depends upon it
change accordingly is simply invaluable, so I cannot see why this
would be bad. That's precisely the behavior I want.

For example, in my miniature aircraft I envision, there is only one
fuel tank, and it's cylindrical, but its radius and length are a
function of several other parameters.

I am guessing that, like in programming, there is an art to
structuring the interdependencies so as to minimize likelihood of
running into dead-end that you mention.

Finally, I was really surprised to learn that parametric modeling was
not fundamental in all CAD programs. I cannot imagine what it would
be like to try to optimize a design without it. What do people do
without parametric modeling? Tweak every single component manually
during optimization phase?

[I am going to give Alibre a look also.]

-Le Chaud Lapin-