Trouble with Union..

[Derek66]

Help! I've only recently come back to using AutoCAD and might be missing something simple, but I have spent hours on this problem and now need serious help.
I am trying to construct a 3D solid, part of which looks a bit like the front half or nose of an airship. This is made up of 19 segments (think of an orange) - I have tried to construct the "nose" by repeating the segment and then using the UNION command to make a single solid object. All went well to begin with then I started to get error messages such as "Inconsistent face-body relationships" or "Inconsistent containment of intersection curve". I thought that it might be to do with there not being total contact between faces so I extruded the bottom face of the original segment a small amount so that there would be guaranteed overlap. I tried COPYing the segment and then rotating it into place; I tried ALIGNing each new segment and finally I tried 3D ARRAY. In each case UNION sometimes worked but I have not been able to fathom out why and when. The most successful was when I used ARRAY and in the "finished" item I managed to get a block of 6 segments successfully UNIONed , another of 5, a 4 and then a couple of pairs, all adding up to the required 19, BUT I cannot get them all joined together!!! The error message in this case is "Inconsistent edge-face relationships." Can anyone put me right on where I am going wrong? Incidentally I do need the 19 facets on the model so revolving is not an option for me. Furthermore, when I managed to get 3 or four segments UNIONed I tried using that block as the building block for the "nose" , rather than the individual segment, but to no avail.


Extra: I have now attached a file with the original segment shown in the top left and the (almost) finished model in the top right of the page.
Thanks, Derek

[JD Mather]

Download file.
Right click on filename and Extract all.
In AutoCAD - issue the acisin command and select the Unioned Nose.sat file

[ReMark]

Does the file, unioned nose.zip, include an explanation on how to do it in AutoCAD?

[JD Mather]

Does the file, unioned nose.zip, include an explanation on how to do it in AutoCAD?

No. I used a modern MCAD program. Might also try FREE Inventor Fusion http://labs.autodesk.com (I don't know how to use that program - so didn't try it.)

[ReMark]

The OP is using AutoCAD 2004. I have the feeling he is not going to run right out and buy Inventor 2013. I thought it might be useful to him if you explained how he might accomplish the same result using an out-dated and less-than-modern CAD program.

[JD Mather]

I have the feeling he is not going to run right out and buy Inventor 2013...

Inventor Fusion 2013 is free. I would not even bother in AutoCAD 2004.

If the OP has an internet connection - won't need to run anywhere. Simply download http://labs.autodesk.com

[ReMark]

Derek: Any chance you are going to download "free" Inventor Fusion 2013 and learn how to do this on your own or would you rather know how to do it in AutoCAD 2004?

[Derek66]

Wow! Thank you so much J.D. and thank you for your concern ReMark. I would like to know how to do it in AC 2004 but I am going to download Inventor Fusion and see what road that takes me down. I will be back to let you know how I get on but, as someone else once said, "I might be gone for some time..." Hopefully not too long though; Thanks gain for the immediate fix, I really appreciate it.

[Derek66]

OK , back sooner than I thought. There does appear to be a free Trial version of Inventor Fusion but the link would not work (possibly due to my geo-location or even speed of connection - I am in the mountains) but I'm afraid the full version - and it does look fantastic- will not be an option for me (unless I get my current project off the ground!) So, thanks again for the corrected solid J.D. , but if anyone knows what I was actually doing wrong in AutoCAD 2004 it would be a great help?

[SEANT]

I no longer have access to AutoCAD 2004 to test if this performs any better but try to Union these solids. I modified the profile geometry a bit. With 3D Solids Boolean operations, AutoCAD may work more efficiently with Spline geometry instead of multiple arcs.