×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

[b]ANOTHER AutoCAD MODELLING FAILURE!!![/b]

[b]ANOTHER AutoCAD MODELLING FAILURE!!![/b]

[b]ANOTHER AutoCAD MODELLING FAILURE!!![/b]

(OP)
Whilst attempting to join two relatively basic solids, good old AutoCAD 2005 flashed up this old chestnut:

The Boolean operation on solids failed.
Modeling Operation Error:
     System inconsistency processing edge coincidence.

Bearing in mind that I had no gaps between my objects as I had been very careful about where my object snap snapped to when i was creating them, and they'd both been created in the same U.C.S. AND I'm using a machine with twin Pentium processors and a Gigabyte of R.A.M., should the error message actually have read:

The Boolean operation on solids failed.
Modeling Operation Error:
     AutoCAD mis-sold as having 3D functionality.

??! - Any affordable suggestions would be greatly appreciated,

Kind Regards,

A-A

RE: [b]ANOTHER AutoCAD MODELLING FAILURE!!![/b]

Hi A-A,

Here's a few things that have worked for me in the past:
  • Try making the solid deliberately overlap - this usually works.
  • In the past, I've actually had some luck just changing my view direction (2004).
  • Check and be sure you have all the latest and greatest service packs installed - this can make a difference also.
  • If you're still having trouble, try either recreating, or inserting the shapes you're trying to extrude into an empty drawing.
  • If you're using polylines, make sure they are closed - this is a common one.
  • If you are extruding regions, maybe try converting them into polylines instead.
HTH
Todd

RE: [b]ANOTHER AutoCAD MODELLING FAILURE!!![/b]

The only other thing I'd have to add is: may be you are too far away from the Origin. Long distances throw errors into the floating point calculations.

RE: [b]ANOTHER AutoCAD MODELLING FAILURE!!![/b]

I think the 3D modeling within ACAD is a waste of time and recources. If you want to design in 3D, use SolidWorks Inventor, ProE, UG or CATIA.

Chris
SolidWorks 07 3.0/PDMWorks 07
AutoCAD 06
ctopher's home (updated 04-21-07)

RE: [b]ANOTHER AutoCAD MODELLING FAILURE!!![/b]

The first reply was the best. ACAD 3D is very robust, and quite stable. It's not as much 3D as S-W, S-E, Iv, etc, but I consistently get great results with it. Add to that the excellent lighting and rendering tools, and you can really get some amazing results.

Now to your problem.

Overlapping may actually be the key here, as the post by tcarpenter1 suggests. While later versions handle this particular problem better, what you may be encountering (not seeing your actual model) is a divide-by-zero issue. If edges that are to be calculated to be removed are aligned as EXACTLY as can be achieved by ACAD using osnap, you might be actually creating the problem. I remember encountering this issue at 13 and again at 2000i, but havent seen it since. Apparently 2005 (I skipped that one...) has the same problem ?

Good luck-
C. Fee

RE: [b]ANOTHER AutoCAD MODELLING FAILURE!!![/b]

(OP)
Dear All,

Many thanks for your thoughts, I can't download any-more service packs here as our firewall set-up is tighter than a nun's proverbial! I was working fairly close to the origin, so in this instance I don't think that this was the problem - though I too have experienced the UCS issue in the past. It's an interesting thought that exact alignment might be the source of the problem, I'll have to experiment further, though I have found that AutoCAD sometimes leaves lines on 3D objects after Boolean ops, which don't appear to represent anything. I tend to take profiles from the 3D objects anyway so it's not too of much of a problem deleting the said lines, just another AutoCAD 'quirk' I imagine.

RE: [b]ANOTHER AutoCAD MODELLING FAILURE!!![/b]

Hi A-A,

Quote:


...though I have found that AutoCAD sometimes leaves lines on 3D objects after Boolean ops,...

Now I'm pretty sure alignment is your problem.  These probably aren't lines, sometimes you can actually zoom in close enough to see it's actually a "hole" in your solid.  While AutoCAD can work in 3D fairly efficiently, it's not as robust as say a Pro/E, Catia or UG.  The latter packages are robust enough to tolerate some "slop" - and would have closed the "hole" in your solid - AutoCAD is not as robust, and has to have a high degree of accuracy or the models (and AutoCAD) can bomb.  I blew a big project this way when the models became so corrupt I couldn't make the deadline of my client!  You might try the following when working in 3D, change your units to decimal, and set the precision on it's highest setting, for both linear and angle measurements, and make sure you always use osnaps to ensure things "connect" without leaving gaps.

HTH
Todd

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources