Boolean issue

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Paul

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Registered: 2011-7-12

Message 1 of 5

 Boolean issue
13-07-2006 01:43 . pm | View his/her posts only
Many times we've run into an issue of not being able to boolean a fairly complex part with a simple extrusion that was built from a sketch.

What I will do typically after the boolean doesn't work is make intersection curves by using shape to shape intersection. I will attempt to chain select the intersection curves. Where the chain selection fails I will focus on modifying the same area in the sketch that drives the extrusion. Usually after several tweaks in the sketch this will allow for the boolean, but there are times when we have to individually trim out surfaces.

Someone asked me today "Why should there be broken intersection curves when it is obvious that there is a full intersection between the 2 closed shapes to be booleaned?" That was a pretty good question but I guess I've just taken it for granted that flaws within the solids cause this issue.

Let's say that there are there are some borderline surfaces that are causing the problem; is there a way that these surfaces can easily be cleaned for better downstream use?

Would this be an instance where reducing points on the surface could help? Would there be other reliable ways of cleaning up the questionable surfaces?

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OldForumPost

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Registered: 2012-1-14

Message 2 of 5

13-07-2006 05:41 . pm | View his/her posts only
Hello Paul,

Sorry there is no general answer ... BUT it is more than important to get the problem files into the VX PCR system to forward the problem to the developers. So please send a PCR or send the files into the forum with a small description and I will forward it to the right person.

Thank you for your help.

Thomas

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ChrisWard2k2

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Registered: 2011-11-22

Message 3 of 5

13-07-2006 06:18 . pm | View his/her posts only
Hi paulverisor

Actually, it makes little difference having closed shapes (solids) - VX can boolean open shapes anyway. Ensure that the extruded shape fully intersects the main body when you define it. With the extrude option set to "add" (boss), try loosening the computational tolerance via Edit Preferences. Having a tolerance that is greater than the width of a tiny "slither" face can make the boolean work.
Having seen your files before, I know that the main body is likely to include non-native geometry. It is worth trying to clean this geom, in particular use the (automatic) commands "delete tiny edges" [Heal Tab, Btn3] and "concatenate edges" [Free Form Tab, Btn10, Btn05]. This will also help fillets to work better.

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Tim

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Registered: 2011-10-31

Message 4 of 5

14-07-2006 01:35 . pm | View his/her posts only
If you report one of your "most typical" (if there is such a thing) problems as a bug, I can advise you on what the problem is, in general, and possibly how to avoid it or fix things up. After you report the bug post the bug # here. Of course if it is a straightforward bug I'll just fix it...but that's not likely.

I'll be out next week though.

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Paul

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Registered: 2011-7-12

Message 5 of 5

14-07-2006 04:51 . pm | View his/her posts only
I'll see if I can find a good example file and submit it as a bug, even though this may not be a bug per se. This may be a good way of spearheading a prescribed methodology to make "dirty" geometry "clean".

Thank you Chris for a couple ideas in how I could attack a tough to use model. I will definately see what this might do with tough boolean and filleting applications.



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