part modelling question

Hello group,

I was reading the "Undercut Detection" thread started by Matt. I found an
interesting sheet metal part he had in the same directory as the part
mentionned in the post. Here is the part in case you would like to take a
look at it http://www.dezignstuff.com/swparts/FormAcrossBends.zip

I hope that Matt doesn't mind if I post a link to one of his parts.

My question is...

I would lie to do a deformation like this
http://img120.echo.cx/img120/431/40sj.jpg

on a lofted sheetmetal outside wrap shown here
http://img120.echo.cx/img120/1153/19qq1.jpg

the part is constructed with two 3d splines (bottom and top)

I'm not sure how to approach this.

The deformation does not have to visible in the flat pattern.

Thank you,

Knotfreak

 

There are probably several better ways to approach this. But here is
one that I think will get you where you need to be.

-create a new configuration as performing this will mess up your ability to
flat pattern the part
-create a split line on the face on which the form will appear
-perform two surface offsets of the surface within the split line-one with
offset of 0
-one with an offset = the desired form depth
-cut thicken the 0 offset surface to make a hole through your part
-surface thicken the other offset ( same as metal thickness)
-use a loft-thin feature from one perimeter to the other
-radius as necessary

Unless you were going to be using the same forming tool in similar
situations frequently, I think you would have more time invested in trying
to make it work rather than trying a one-off method.

 

If I post stuff on my site, I expect people to take it and use it however
they want. If it was sensitive info, I wouldn't put it where everybody
could get it.

Anyway, here's a crack at it using a different method. SW05 added the
"Indent" feature which is cool for this sort of thing. It requires a
little multibody work, but nothing too difficult. I think it's easier than
the surfacing method the other fellow mentioned.

I modeled the inside of the deformation as if it were created by a tool.
You only have to model the punch side, not the coining die because you
assign a thickness in the Indent tool. It's not meant specifically for
sheetmetal parts, but it works with them too. It's similar to the forming
tool, but skips a few steps.

www.dezignstuff.com\swparts\indent.SLDPRT

Good luck.

Matt

 

Thank you both for your help.

I tried using both techniques but I wasn't able to reproduce the result I'm
looking for. The problem lies in the fact that the "bead" should follow the
contour of the part.

Here's what I'm trying to do.

http://img173.echo.cx/img173/152/dsc000020jn.jpg

I tried using the spline on surface command but didn't really get anywhere
with it. Any other ideas on how to do this?

Knotfreak

 

If you were going to use the "indent" technique, you could do a zero offset
surface from the inside of the part, hide the solid so you can see the
surface, then work on building the indent tool from there as a separate
body. How you proceed depends on what information you have. If you're
just making a "looks like" model, the 3d spline on surface might be a good
place to start for a sweep. Really, there are a lot of things you could
do, like ...

-an extrude offset from surface/reverse offset with a chamfer
-a sweep
-projected curves to make a sweep
-split curve, offset surface, loft between faces
-cut a hole, make a curve, loft between curve and edges of cut


Really, the number of things you can do here is limited only by your
inventiveness and what type of information you're starting from. The less
info you start from, the more freedom you have in how to create it.

Anyway, good luck.

Matt