PROBLEM UNION SOLIDS

[wolverine01]

I am trying to create a 3d CAD topographical model. Once the model has been created in AutoCad we will be using it on a CNC machine to create a physical topo model.

I am aware that there are a few different ways to create this Cad model. However, our chosen way is to create a series of closed spline lines for each contour line.

I would be happy to e-mail the file however it is too big to upload here.

Our contour lines have been set up so that each line has been drawn at 2’ high intervals.

Once the line has been created we then move them in the Z value so they are at the right level. In other words contour line 2’ has been raised 2’ from Z value and contour line 4’ is 4’ from the Z plane.

Our procedure then is to extrude each line by 2’. Then what we do is UNION each 2’ solid to create the model.
The problem we have is that some solids just are unable to UNION together.

Where this happens we have re drawn the spline then extruded it again and it still does not work?
Would really appreciate some help in this matter.

We get these following error messages.

The Boolean operation on solid and/or surface bodies failed.
Modeling Operation Error:
System inconsistency processing edge coincidence.

The Boolean operation on solid and/or surface bodies failed.
Modeling Operation Error:
Curves osculate at vertex - cannot evaluate order.

[JDMather]

I don't understand why you are moving the contour line elevation. Simply extrude each contour from the z-plane be the required height.

First make sure that 0,0,0 is at the approximate center of the contours.

Can you attach the file here if there are no extrusions? (just the spline contours)

Right click on the file name and select Send to Compressed (zipped) Folder.

Attach the resulting *.zip file here.

[wolverine01]

  Yes very good point with regards to moving the spline line.  It makes little sense to move the spline to the correct height then extrude the same distance back again.

However, the real issue is working out why the solids do not union and we get the error message as mentioned above?
Flat contour line attached.  

This drawing has needs to be scaled 12 times as it was the drawing we traced over from the survey.  Had we posted  the scaled up drawing it would have been too big even if zipped.

Thanks again so  much for your help in advanced.

[JDMather]

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This drawing has needs to be scaled 12 times as it was the drawing we traced over from the survey.  Had we posted  the scaled up drawing it would have been too big even if zipped.

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I don't understand these statements.
I scaled it up 12 and moved to the origin (it was 130 miles from the origin) and the file is 229k?

[JDMather]

I suspect that the problem is where your profiles are nearly coincident, but not quite identical.  Someone with C3D experience will probably come along and offer alternative solutions.

[wolverine01]

Sorry for any confusion with regards to the scale.

However the problem remains that when you extrude the spline lines then try and union them together some of them work and other will not. When the problem occurs we get the error message as stated above?

Can anybody shed any light on this issue?