1. ## Subtracting..

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Does someone knows why when one solid is subtracted from, for example, 2 solids, and if these 2 solids are almost one in another, then why cad joins these 2 solids to gether and then subtracts the one solid from them?

Regards..

2. because that's the way boolean operations work.
If you require the two parts to stay separate then create two solids to subtract from them

3. Originally Posted by hendie
If you require the two parts to stay separate then create two solids to subtract from them
Or use the solidedit-Body-seParate command. There is an icon for this on the Solids Editing toolbar.

That is assuming, "if these 2 solids are almost one in another" means that they were in fact disjointed solids before the subtract.

4. It doesn't help..
I have an answer :The selected solid does not have multiple lumps. If i move these two solids away one from another so they don't overlap then it subtracts the third solid from these both right.. But before that, cad made like a union command before..

5. Originally Posted by Hmm..
...if these 2 solids are almost one in another..
Are they intersecting or not? Almost means not to me. In fact almost means not even touching to me.

Originally Posted by Hmm..
...If i move these two solids away one from another so they don't overlap...
Are they intersecting or not? If they are, why do you have two solids occupying the same space? Cannot occur in the real world (at least not without some dramatic forces applied).

If you want to subract a common solid from two other solids you will have to use either the method hendie proposed or the method I proposed depending on the situation. You will have to use hendie's method if the other two are even just touching.

I'm assuming that English is not your native language. If you have trouble figuring it out the best way might be to post the file as you have it so far and someone can demonstrate using your actual geometry instead of words.

6. Ok..so here is the situation.. see the file. Subtract the supporting beam from the trusses.
Of course it can't be in real life that these trusses intersect, but while they are under construction they can intersect as they like.. at the end of the project they must be as in real life..

7. First off you need to slice the 2 trusses so that the trusses don't overlap like they are doing..creating the real world cut that would be done on the job site..using the YZ plane and its location at the top intersection of the two trusses..use your intersect snap...now creat the birds mouth that the trusses are cut with for the truss to set on the beam..simple copy the beam onto itself..so now you have 2 beams occuping the same space..subtract the extra beam away from the 2 trusses....Done!

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No + no + no!!! It's too complex!
I need to subtract third one from these two without slicing them or something.. And for copying the third solid into its own place, it's also to complex, and I have written a lisp, that does it instead of me..
I was just wandering, if there is some setting, that unions them together, otherwise ill have to write a lisp for that too..

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