Creating a 3D "wire" shape driven by 2D sketches

I'm working on a project for a client. They have legacy 2D drawings
depicting 3D parts made from bent wire.

I'm thinking maybe I should create the 2D sketches, then create a 3D
sketch that is simply a spline, then constrain the spline points to
the 2D sketches. I would then sweep the wire diameter through the 3D
sketch.

I have never tried to drive a 3D sketch with 2D sketches. Are there
better ways of doing this?

Imagine a piece of relatively stiff wire, contorted into a weird 3D
shape

The shapes would be much like those toys you see in waiting rooms for
very little kids - where there are wooden beads on bent thick wires,
and you push the beads along the strangely-shaped wires.

Thank you for any help you may have!

 

If the drawings have dimensions, why not just create the 3D sketches and go
from there?

WT

 

You might be able to take the 2 2d views, place them on planes, align
them and use the Projected Curve to make a single curve that does it
all. Assuming the original autocrap drawings are accurate, which they
never are.

Making a spline that is driven by the 2D sketches wont work the way you
think it will.

 

Insert, curve, projected, "sketch on sketch" can create a 3D curve from two
2D sketches. You may need to make sure that the imported 2D profiles don't
have gaps, etc. If the curve needs to be a sketch entity (instead of a
curve entity. I don't know why there's a difference), you can create a
3DSketch after the curve is created, then use convert entities to make a
spline version of the curve.

 

If you want to have a 3D sketch driven by points in a series of 2D
sketches, this is valid, especially if you are uncomfortable/
unfamiliar with 3D sketch. There is a lot of weird stuff with 3D
sketch, especially depending on your version of SWx and the
constraints allowed in your version. It is often easier (and
certainly more stable) to nail important routing points in a 2D sketch
than with a 3D sketch.
I have often used a series of 2D sketches to create points that my 3D
sketch would go through (or the old-school curve through points, which
you should not use because a 3D sketch spline does the same thing but
with wayyy more editing flexibility)
Even though I am comfortable with making 3D sketches, I still find
myself laying out points in 2D sketches and using them to drive the
final 3D sketch because it is consistently stable and fits in with my
mindset. When there are multiple ways to approach a problem (which
happens often with Swx) go with what you know and are comfortable with
to get your job done,

Ed

 

Where do the beads go when they vanish?

And how can a soft purring pile of fur at random invert (in about
5 miliseconds) into a flashing thicket of nothing but claws & fangs?
Topology problem I think. HOW did all that stuff get on the inside
in the first place????

 

MIMSY WERE THE BOROGOVES, by Lewis Padgett, published 1943

http://jabberwockland.blogspot.com/2007/03/mimsy-were-borogoves-by-lewis-padgett.html
[
Meanwhile, in the adjoining room, Emma was sliding the beads to and fro in the
abacus. The motions didn't seem so strange now. Even when the beads vanished.
She could almost follow that new direction almost-
]

 

IF it is ...
Transform the 3 "planar" views into real 3D .. one top, one side, one front.
Project all three (leaving ruled or other developable surfaces) a distance
into the interior "volume". Intersect the surfaces.
Toss out bad intersections (not all 2D views resut in a single possible
3D answer - hence programs claiming to do that often fail),

Do they need it to be a spline? Probably arcs & lines ...

BTW, There may be specialized bending data associated with the
original? Or are these four-slide parts? Still might have some -- I don't
know that field.

 

Forgive me for nubieness, but I'm following this thread for personal
interest, and I'd like to be sure I understand... there is no way to
translate a 2D curved bezier line into a 3D spline drawing? It would
seem like a very straightforward thing to do, given that the z
dimension is a known quantity.

I was fooling around with this question, and I realized that things
like line-overlaps in the bezier line (loop-de-loops and the like) are
a bear to convert. But even so, in 3D modeling progs intended for
graphics purposes, this is never deal-breaker.

Surely there is a simple way to yield the desired 3D sketch?

Merci and gracias for further clarification.
diane

 

No, not a deal breaker at all. There are several ways to do it in
SWx.

1. Projected curve, when the 3D curve can be COMPLETELY defined by
two orthagonal projections. Think of it this way - if you could
extrude a surface in one direction then cut (trim) it from another
direction and get the curve you want, you can use projected curve.

2. Curve through reference points, but don't use the curve feature
'curve through reference points'... use a 3D sketch instead and make a
3D spline with spline points coincident to the selected points so you
can use editing options not available with 'curve through reference
points'. Think of 'Curve through reference points' as being similar
to your appendix - it might have done somethoing in the past and
though it is still there you can safely live your life without ever
using it. Using a 3D spline is so much more flexible you can just
remove 'curve through reference points' from your toolbars. It has
been obsoleted.

3. When I want a specific 2D curve to be translated into 3D and
option 1 is not appropriate, I make my desired 2D plan or elevation in
a sketch. Then I make a 3D sketch and draw a spline, dropping Z
paralell cventerlines down from the nodes to be coincident to the 2D
sketch. This allows me to adjust the Z independent of the XY which are
constrained by the 2D sketch (Tip -I usually use the property manager
for fine adjustments to adjust Z instead of adjusting on the screen)
However, this takes a real big understanding of splines to make it
work well. It's hard to describe - its better to try it and you will
see what I mean.

4. Break curves that cannot be described by option 1 into a series of
projected curves that can be described by option 1. Then use
'composite curve' to stich 'em all together into a single curve.

 

Ed,

This is VERY helpful. You're golden.

vinaka!

d