Side tangency for surface lofts

Hi

Note that I'm asking about surface loft with guide curves (not solid loft):

Can anyone remember, in 2003, whether the adjacent faces for side tangency
(outboard of the guide curves) were ever permitted to be surfaces? If so,
which SP or SPs?

I'm doing a project which has to be done in 2003 SP3.1, and it only seems to
accept solid faces. Seems weird for a surface loft.

I'm ALMOST sure it used to work.

(Some people say you get Alzheimer's from licking aluminium pots; I reckon
you get it from solid modelling)

TIA

Andrew Troup

 

I'm getting new version burn out. I didn't think GC side tangency for
surface loft came until 2004. Dunno. And of course you don't have the
Fill in 2003(?), or the intersection curve.

Can you turn your loft 90 degrees so the end tangency comes off the old
GCs? Or maybe just make temporary solids to assist the loft. 2003 had
multibody.

You ought to charge your customer more to work in old forgotten versions
where you have work around things that have been fixed long ago.

 

Thanks for that matt, your input is always helpful and thoughtful - Sorry to
strain your memory so unfairly.

I built a study model to try to get to the bottom of why side tangency is
not available to me in this situation. Turns out that GC side tangency for
surface loft DOES work in my 2003 study model (built entirely from
surfaces).
The real model is one in which I've had to harvest surfaces from the face of
a solid model built by the client, and I thought perhaps Side Tangency
didn't work in mixed models, but when I added a solid to my study model, it
didn't break the loft.

Actually 2003 does have Fill, and intersection curve, so I didn't have to
resort to the right-angle turn (in any case, I wanted end control as well).
There were only a couple of faces of the loft where the lack of side
tangency was causing problems (inability to do a thin shell) so I deleted
those faces and patched them with Fill and was away again. I do hate having
to complicate the model with these arcane workarounds, particularly as my
client has to run with the model as part of an assembly, but, hey, life
would be boring if everything could always be done elegantly.

The only thing in later versions I really miss for this project (fairly
complex sheetmetal deep-draw pressings, mixture of prismatic and flowing) is
variable radius fillets for surfaces.
I'm having to drop back into solids at various stages of the model for this
reason alone, but it's a real pain that variable radius fillets also don't
work for multibodies - I end up having to delete and recreate the same solid
over and over to work around this.
---

There's an interesting paradox floating in your reply: strikes me that the
"new version burnout" of which you speak is avoidable, in theory, by
stepping off the upgrade treadmill. All we need to do is hold secret talks
so everyone can form a chain of solidarity and step off at the same moment !

"things which have been fixed long ago" per your reply would be great, were
it not for "things formerly fixed now broken" or "things which always worked
but no longer do".
I personally have reached the point where I would prefer to become
thoroughly familiar with how to work around a finite (albeit very large) set
of limitations, than to forever be butting into new ones, or finding that
old workarounds no longer work.

I know it's not strictly comparable, but in the 2D era I had the fortune to
gravitate, early on, to an extremely simple and elegant CAD package, which
was discontinued before it ever had a chance to develop mission creep and
legacy pustules. We stuck with it for a decade, because although it had a
few huge vices, it had serious virtues, and we gradually knocked out almost
all the vices, due to the sophisticated workarounds permitted by the depth
of our eventual familiarity.

I look forward eagerly to the time when 3D solid and surface modelling is as
transparent to us users as we long for it to be, and our expertise can once
more be focussed almost exclusively on the task instead of the tool.

Andrew Troup