Silhouette Curve does not work

[karthur1]

I have a part that I need to make an impression for and I need to generate a silhouette curve.  My actual part is much more complicated than the part shown above, but the above part shows the short comings of the silhouette curve command.

After I made the silhouette curve, I projected it onto a plane (sketch 5 in the part).  My workflow was to use this projected sketch to project an extrusion back up to the solid body.  I would then have an impression of the part.

The problem with the silhouette curve is in the area of "1" and "2".  In these areas, when the 3D curve is projected onto a 2D plane, it has areas where the lines either overlap or do not meet.

Maybe I am doing something wrong and someone can show me what to do to correct this, but it seems like it is the way the silhouette curve projects the geometry. To me its pretty much useless. What I would like the command to produce is a "true" silhouette of the object (without any overlapping edges or gaps) that could be used to extrude.

Kirk

[innovatenate]

Kirk, 

After reading the description for the silhouette curve in the help file. I'm not positive that the tool will generate the desired result for this geometry.

http://help.autodesk.com/view/INVNTOR/2014/ENU/?guid=GUID-5C99E95D-426D-4208-B664-2B18A5529CE7

You may consider the following solution, instead. Create a drawing with a base of the "Top View" and then export the view to a dxf file. That will give you a true projected 2D geometry. You can re-import this geometry into the model environment or use elsewhere, as needed.

Let me know if this helps.

Thanks,

[karthur1]

Nate,

I guess importing back in the 2d sketch will work.... its just not associative.  I will have to try it a see how it turns out.

It just frustrates me that the silhouette curve command will not give what it says it should output. It says "....Visualize a beam of light cast along the direction vector shining on the object . The silhouette curve is generated where the light drops off and the shadow begins.  A primary use of the silhouette curve command is to determine a natural parting line...."

That is exactly what I want. but when I do that, in the area #1, I get something that looks like this.

This does not work to well for a closed sketch that I can extrude.

In area #2, there is also a break in the curve.

Inventor knows how to generate what I am after, I just dont know how to get it out.

Thanks,

Kirk

[innovatenate]

Kirk,

What about modifying the pull direction? I used the reference line as the pull direction. See attached for file for more detail.

[karthur1]

That is a good try, but the projected curve still wont project because there is a gap here.

I also tried bringing in the dxf file and it didnt work either. It got close, but there were two small areas that it did not meet up with the solid.

Still trying different things.

Thanks

[JDMather]

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@karthur1 wrote:

....  My actual part is much more complicated than the part shown  ...

 Kirk

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I am confused - is the part you attached what you are working on or is it a simplified trial?

I took this part into Inventor Tooling and found problem that it didn't seem worth the effort unless this is the actual part.

[karthur1]

JD,

The actual part that I am having trouble with is much more complicated than this.  I havent gotten very far with it, so I thought that I would take a step back and see if I could accomplish the same thing with this simple part.  If I could make the tooling with this simple part, then my plan was to use the same workflow to build the tooling for the more complicated part.

I have tried to use the Mold environment to do what I want, but iI could not figure out this.

When I created the runoff surface, I only have an option to go a +/- X or +/- Y.  I need it to go at a certian angle.  I need it to go perpendicular to the bottom face of the part (in the direction of the blue arrow).

Sorry for the confusion.

Kirk