Weak or fuzzy mates

The challenge: I have a very slightly curved lofted surface with a
number of (about 20) holes cut for windows.

I also have a window part which fits the cut holes, but not exactly,
since the window edge is planar, but the cut holes have spline edges and
a very slight curvature to the faces, slightly different for each hole.

Now I don't care about a few tens of a millimeter mismatch between the
window and the wall cut, because there will be a 2-4mm wide weld there
anyway. But SWX cares, and makes it very difficult to mate the windows
to the holes.

I was looking for some kind of weak mate where I could basically say
place these three points on the window fram as close as possible to
these three points of the window hole cut (But only one point can be EXACT).

Seems to be no such thing. Any ideas how to accomplish this without a
lot of manual positioning (that won't update with modifications) would
be greatly appreciated!

/C

 

You can do it this way but it is tedious.... especially because you
must iterate each step for each window but it will properly position
your windows.

Create 3d sketch - convert edge of window openiing into sketch. This
will be a spline with 1 start/endpoint. Create 2 more points on the
spline. Close sketch. Use these 3 points to create a plane. Create a
2d sketch on this plane, sketch a circle and create relations between
the 3dsketch points and the cirle to center it over the opening. Then
you can mate your window to the centerpoint or edge of the sketched
circle. (note: there are many variations instead of sketching the
circle - find what you like the best)

Told you it was tedious and I would love to see another better way
posted.!

 

If you can place ONE point precisely on the spline edge of the holes,
and if that can be at the topmost or bottommost point, then I have a
solution for you . . . I think.

What you do is to create an axis which is vertical -- maybe using the
Front and Right planes if that is how your assembly is oriented.
Hopefully your window parts are symmetrical to their own Front/Top/Right
planes and one of those axes (for each window part) can be made
Coincident to the point that you place one the spline edge of each
hole. Then you can make that same axis also Parallel to the Assembly
axis that you created. Finally you can adjust the tilt of the windows
and their proximity to the part with holes in it so that they fairly
closely match the curvature of the outside of the part. You MIGHT be
able to do that by making one of the window planes Tangent to the
outside curvature.

'Sporky'

 

Mr Voltin is exactly on target here. The application is a aluminium boat
hull. The window is an off the shelf purchased part. It is welded to an
opening in the sheet metal making up the hull shell. The hull is fully
curved in all dimensions, but to the welder this curvature will only
cause a gap between the window and the hull an order of magnitude
smaller than the weld itself, and it is thus totally insignificant.

I used to model things the way Mr Mossberg describes for the conceptual
model, but I am now doing the engineering model, and need a single part
with correct BOM data for all 20 windows. Unfortunatly there are still
changes in the hull shape expected from the hygrodynamic analysis, so I
need the model to be fully associative as well.

Thanks for your kind input!
/C

 

If you are using SW2006, there is a new width mate that allows you to
position something to stay half way between two other things. Might help
you.

WT

 

Good suggestion! It turns out it still wants to be EXACTLY half way, so
it didn't help :-(
/C

 

No, then it would be easier ;-) The hull is curved in all dimensions,
and the windows need to orient themselves towards the hole as well as
possible, while not being constrained any other dimension except that
the x axis of the window is paralell to the top plane of the assembly.

The holes are created by a cut extrude of the shape of the window from a
plane tanget to the hull curvature at the center of the window. Thus all
edges of the hole are splines.

The way I figure I will do it now is by mating each a fixed distance
from that plane. The drawback of that is I have to carry all the planes
over from the hull part to the assembly. (I'm trying to cut down on
relations between parts, since this model is already almost out of hand
in complexity )

/C

 

limit mate?