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Reid
28th Dec 2009, 04:31 am
Hello, I am a a moderately advanced user. Is there a way to split solids, say, I have combined 6 boxes and a cylinder in the center to form a fan, via the union command, and now I want to separate them again. At present I have one solid entity. I can do stuff to faces and explode them, but don't know how to return to having six separate boxes and the cylinder. Slice is one option, thinking of one simpler

viviancarvalho
28th Dec 2009, 07:08 am
Reid
According to me slice is the only & the best option of seperating the solids. Although if you are finding it difficult,you can attach it here i ll try to do it for you.

kencaz
28th Dec 2009, 08:23 am
Reid
According to me slice is the only & the best option of seperating the solids. Although if you are finding it difficult,you can attach it here i ll try to do it for you.

I agree with the slice option, also you can set the solid history to Yes and it will show the outline of the separated solids for reference.

KC

ReMark
28th Dec 2009, 12:21 pm
What is the system variable DELOBJ set to?

DELOBJ

"All defining geometry is retained."

JD Mather
28th Dec 2009, 01:00 pm
If any of your slices are not planar then create Surface bodies for using with Slice. Use the option to retain both sides of the slice. You might check the tutorials in my signature.

Reid
28th Dec 2009, 02:36 pm
Thank you. DELOBJ is 1. Slice will not work with spherical intersections. I am after a routine rather than a single task. Is DELOBJ equivalent to Record History? Cad keeps history of Boolean, but only as long as there is no editing to sub objects. I kept Record History turned on, but lost Boolean history anyway after editing some faces and could not retrieve it

ReMark
28th Dec 2009, 02:58 pm
DELOBJ

"Controls whether geometry used to create 3D objects is retained or deleted."

Since your variable was set to 1 the profile curves were deleted (includes those used with extrude, sweep, revolve and loft commands).

You're asking if there is a routine (LISP?) for handling spherical intersections?

Reid
28th Dec 2009, 03:11 pm
was not thinking about LISP in particular, just a principle in general. I'll see to DELOBJ, but ain't it the command line for Record History.

ReMark
28th Dec 2009, 03:24 pm
Are you referring to SOLIDHIST?

"Controls the default History property setting for new and existing objects. When set to 1, composite solids retain a “history” of the original objects contained in the composite."

JD Mather
28th Dec 2009, 03:25 pm
Slice will not work with spherical intersections.

Sure it will.

I would not have record history turned on - I have seen many problems with this.

If you follow the instructions in my tutorials Delobj should be off - put generating curves on hidden layers in case you need then later.

Zip and attach your file here.

ReMark
28th Dec 2009, 03:26 pm
From AutoCAD Help:

To specify that a solid will record a history of its original forms.
If the Properties palette is not displayed, click Tools > Palettes > Properties.
In a drawing, select a solid.
On the Properties palette, Solid History area, under History, select Record.

JD Mather
28th Dec 2009, 03:28 pm
I am after a routine rather than a single task. ... but lost Boolean history anyway after editing some faces and could not retrieve it

AutoCAD is limited in 3D tools such as what you are trying to do - more of a brute force approach is generally required.

Autodesk Inventor is probably more appropriate - the tools have already been coded, and you would not lose feature history.

Red333
28th Dec 2009, 03:41 pm
Do you have mass elements? I haven't used AutoCad '09 much, but I use Architecture '09. When I'm separating solids in ACA, I convert the solid to a mass element, then use the trim or split by plane commands. Then you can convert it back to a 3D solid.

ReMark
28th Dec 2009, 03:43 pm
No mass elements in plain AutoCAD 2009 that I am aware of.

JD Mather
28th Dec 2009, 03:44 pm
Do you have mass elements? I haven't used , ...then use the trim or split by plane commands. .

Vanilla AutoCAD does not have mass elements and the OP indicated a desire to split with sphere. Vanilla AutoCAD will allow split with a planar or spherical surface.

Patrick Hughes
28th Dec 2009, 04:54 pm
was not thinking about LISP in particular, just a principle in general. I'll see to DELOBJ, but ain't it the command line for Record History.

Reid, a habit I've gotten into is, as I'm constructing my model I frequently wblock out the primatives I'm working with. Or, I'll saveas the model at various stages in numeric sequences. Then if I decide to change things It is simple enough to revert to a certain level.

If you haven't done something along those lines you can always explode the model and use the elements to recreate. I've found this to be somewhat messy, and it is only as a last resort.

JD Mather
28th Dec 2009, 05:01 pm
... you can always explode the model and use the elements to recreate. I've found this to be somewhat messy, and it is only as a last resort.

I think I would wait to see the file before suggesting explode.
Color and xedges might also be of use. Perhaps solidedit separate at some point. But without the file....

Patrick Hughes
28th Dec 2009, 05:08 pm
Yep, that's why I said only as a last resort. I'll add whenever an explode is done always, always, always retain a copy of the original.

Did I mention Always?

Reid
28th Dec 2009, 06:30 pm
If any of your slices are not planar then create Surface bodies for using with Slice. Use the option to retain both sides of the slice. You might check the tutorials in my signature.

thanks for all tips.
I don't have a specific file. I am after the concept as it is often handy to detach previously joined elements. Yes, surface will cut spherically as 2d extrusions will. don't know why retain both thou.

ReMark
28th Dec 2009, 06:44 pm
I believe that is the default option which the user can override. who knows how or why the programmers design it this way. Only the Shadow knows.

JD Mather
28th Dec 2009, 07:01 pm
I have combined 6 boxes and a cylinder in the center to form a fan....


I don't have a specific file.

Uhmm, do you or don't you? If all you need was examples I could have suggested doing the tutorials in signature in the first response.

Reid
29th Dec 2009, 06:19 pm
well, not examples. All i had was a cylinder with six boxes around it intersecting and joined to this cylinder.