create smooth curved solid 3D in AUTOCAD

[Anonymous]

I have the problem in AUTOCAD how to create curve in 3D to make a solid 3D curved transition

[john.vellek]

Hi @Anonymous,

Can you attach a sample or illustration of what you are trying to build?  I look forward to helping you.

[rkmcswain]

Does this help?

[Anonymous]

the follow attached contain my model,I want to connect this two parts by a curved 3D, But the broblem is the difference in elevation between two parts which arc can not be created in 3D

https://drive.google.com/open?id=0B3t03lOcC-CSWUlmb0xaUnNTSEE

[Anonymous]

ok

[Anonymous]

thanks, Your video is benefit but I dont know how much the rotational angle it is irregular shape

[john.vellek]

Hi @Anonymous,

I apologize for not getting back to you earlier on this.  I am still playing with this issue and making a bit of progress. Building a 3D arc has always been a bit tricky.  Typically, one would create a UCS based upon three points but perhaps due to my lack of expertise this wasn't working very well for me.

I had better luck creating a solid between the two structures and then creating a 3P cylinder attach to the two corners that are at different heights. Then I used a Subtract so that only the concave solid remains. It is still not perfect so I haven't attached it yet but I am going to give it another attempt.

Thanks for your patience.

[Michiel.Valcke · Accepted solution]

I added two closed 3dpolylines (3DPOLY) to the face of each end and then used the LOFT command to connect them. You can choose a guiding line if you want to accentuate a certain shape or curve. You can also play with the vertex to change the smoothness and the settings of the curve.

If you make a 3D Arc first you can use that as a guide so the solid will follow the shape and angle of that arc.

I hope this helps

[SEANT61 · Accepted solution]

Here's another method of creating that transition.

Extract the edges of the two rectangular ducts.  Create a Blend curve between corresponding edges.  Loft surfaces for each set of Blend curves. 

[Anonymous]

i is a good idea

thanks

[Anonymous]

thanks, but how to create blend curve in  3D

[Michiel.Valcke]

I'm not really sure what you mean by that.

But can the command BLEND help you?

you make two polylines along your duct and then use the blend command to make a spline in between them that is adjustable.

[Michiel.Valcke · Accepted solution]

Is it something like this that you want to do?

[john.vellek]

HI @Anonymous,

I am checking back to see if my post or others helped you with your problem.
Please add a post with your results so other Forum users can benefit.

Please select the Accept as Solution button if a post or posts fully solved your issue or answered your question.

[elshawadfy · Accepted solution]

Hi @Anonymous,

You can also copy both rods first and - 

1- convert both geometries to NURBS (CONVTONURBS)

2- Delete the end caps surfaces where you want to connect your geometries..

3- Use SURFBLEND to connect both ends:

     - CH (for chain) > select first rectangle >  enter

     - CH (for chain) > select second rectangle >  enter

     - You'll see 2 small icons at both ends, click on each and change the continuity to curvature G2.. then Enter..

4- You can now copy the newly created element to it's original place.. and delete unnecessary elements..

 Regards..

[Anonymous]

when I want to create loft using guide it does not work (for arc it worked), but in my case I created curve using coordinate by Spline, please see attached

https://drive.google.com/open?id=0B3t03lOcC-CSTXJGb3MzNXFmUzQ

[SEANT61]

See the screencast below to see how I envisioned the ‘Blend Curve to Surface’ approach.   The process is a variation, with essentially the same results, of the process demonstrated by elshawadfy.

The attached file has all of the surfaces lofted, plus that geometry unrolled if this is a ‘tin knocker’ project.

[Anonymous]

this is surface (not Solid body) any way, I can generate loft for this case but if guide is curve (part of circle) but for attached profile I constructed using coordinate (may consists of some circles) it does not generate

[SEANT61]

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@Anonymous wrote:

this is surface (not Solid body) any way, I can generate loft for this case but if guide is curve (part of circle) but for attached profile I constructed using coordinate (may consists of some circles) it does not generate

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I'm having a bit of trouble understanding.  The one part I did follow was that my assumptions were not correct. 

Are you reverse engineering existing components - and trying to fabricate a connecting part? 

[Anonymous]

thanks, your method is quite good, but when I repeat same thing transition does not create (for Solid 3D), for transition design I used a function (x=ay^b), this produce arc composed more than one curve, finally I want to say transition using one curve (one radius) can be create using loft but for arc (composed multiple curve) can not be create but I do not why!!!, please guide me if Iam wrong