union command

[ica_cici]

Hi, i want to merging 2 parts solid object into one, but after applying the union command, these two parts are still separated. So, what is the problem caused by? please help!

[ReMark]

I'm having trouble identifying what the two parts are. Could you elaborate?

[ica_cici]

Actually, i need to make this shape in solid (see picture), and this following are the procedures:

 

1. Making 2 pline paths.
   
2. Sweep-ing a circle profile (D=0.45) along paths.(using sweep because it won't work with extrude command)
   
3. Merging the two solid objects result into one using union command.(failed)
   
4. Subtract-ing each solid objects by 4 boxes above and below the left & right sides so the thickness left to d=0.28.
   
5. Subtract-ing one end point in order to get gap=0.0001.
   
6. Merging the two result solid objects into one using union command.(failed and still separated)

What is the problem caused by? is it because of my path?(because it's usually work with extrude and union commands if the pline made of circle and line).

Thanks for help!I also enclosing the dwg file.

JOINT-1.zip

[ReMark]

Yeah, I can see why the merging (you do mean "union", right?) fails.

 

Please tell me, as I am always puzzled by this, why do some users, like you, limit themselves to one or two layers then over-ride the layer-color properties? If I easily want to shut-off or freeze something that my eye tells me should be on its own layer (a different colored entity) it can't be done.

 

You have two layers named "0" and "0.2" and everything, despite four colors being used, is drawn on layer "0.2". I don't understand that at all.

[ReMark]

I was able, after a long wait, to extrude a circle along one of the paths but the result looked really weird. How were the paths constructed in the first place?

[ica_cici]

Sorry about the layer , i did it to decrease file's weight (the capacity is max 250 kb for zip).

 

It is true that work with many layers safer than one but I usually use one layer for the solid object.

 

It's make me easier to solprof the object into 2d.

 

Using many layers make me more confuse about choosing the active layer to turn it off for the block step.

 

So, i just use the layer control for the 2d drawing to separate each line types, such as 0.2 for hidden line, dim for dimension, 0.4 for the main drawing, iso for the solid, etc.

 

And for the paths, theiy're made of arch-pline because cannot joint ellipse and lines in pedit. Don't know other way to join lines except pedit. Poor me!

[ReMark]

You can't join the ellipse and pline because the system variable for pellipse is probably set to "0" and not "1".

 

Personally, it looks like the two paths overlap for most of their length. Why is that?

[rocneasta]

ever since Autocad introduced history into 3dmodeling - only i guess to be able to use solidedit commands - at times it's impossible to UNION the solids that have history on record.

 

use BREP on your solids before UNION and it might help. If it doesn't, and in some odd cases it won't i never found the answer why

[ica_cici]

No, BREP doesn't help my solids.

 

I renew my paths and i think I've been figure out what the problem is.

I am using spilne as a path frame and redraw the path frame with arc-pline, then offset-ing the new arch-pline at distance 0.225.

 

I did it for the both paths and wanna use the middle arch pline (offset results) as the main path.

 

But, the main paths points are not precisely in correct and perpendicular with the frame so i made some edit for its.

 

After extruding the two paths and trying to union again it's failed.

 

So, i repeat the steps once again, but without editing the middle arch-pline (main paths) this time and reunion its again. It works, its joined.

 

The big question in my mind now is why editing offset path can make the union process failed?

joint-2.dwg

[ReMark]

Perhaps there was a gap somewhere that went unseen?

[ica_cici]

yeah, perhaps! thanks all:)

[ReMark]

Is this "ring" (for lack of a better word) supposed to be hollow on the inside by any chance?

[ica_cici]

I call it chain's link. No it isn't, it supposed to be full solid.

 

And about the offset, when i am offsetting an ellipse, it would be a spilne and it's point are no longer in the right frame points. Is it always like that?

 

Here another case (see picture), and i cannot joint them with union too although I'm not editing the path.

 

I think I can't trust my self anymore about the union, it make me desperate

joint-3.dwg

[ReMark]

I don't get it. The two parts are almost identical. Why are you trying to union them?

[ica_cici]

I want to get the sizes in 0.50 for the wings (upper & lower) but still in 0.40 for the both ends (left & right).

[ReMark]

Then why not draw cross-sections for each critical thickness transition and use the loft command to create the shape?

[ica_cici]

It's should be a solid wire with thickness d=0.40, if using loft the profiles to loft are a circle with D= 0.40 at the end (left/right side) and an Ellipse 0.40 x 0.50 at the middle of one of the wings, is that what you mean?

[ReMark]

Yes, that's what I mean.

[ica_cici]

I've been trying the loft option for the both cases and it works. Thank you ReMark that's a brilliant idea! The results are smoother and that's easier way.

joint-4.zip

[ReMark]

You're welcomed. I'm glad you got it worked out.