How to create curves in 3D

[Anonymous]

How can I draw a curve in 3D? I mean if you look at the picture you will see an example of an earring that has a number of curves. I, basically, need only one to then use pipe or sweep instrument and later to pattern it. However, I don't see how I create the first curve that bends in 3 along 3 different axes. 

[Anonymous]

Sorry, I have found some solution myself. 

[lichtzeichenanlage · Accepted solution]

Yes you've found the solution but I guess this might be an easier way to manipulate the curve:

• Draw a simple 2D curve in a sketch. 
• Finish the sketch
• Select a sketch point in the model environment and use the move command to move it around. You can do this at any time later, too.

The screencast shows this basic concept.

[TrippyLighting · Accepted solution]

Creating a single 3D spline might seem he natural solution and does provide a great deal of control.the problem is you have somewhat manhandle that spline.

Here is another method that allows you to more easily edit the overall shape.

[lichtzeichenanlage]

Holy s***, that's so much better. And the real sad thing is, that I know this technique but always forgetting it. Silly me.

[Claus_J]

cool!

[chrisplyler]

@lichtzeichenanlage  and @Claus_J  you shouldn't say things like that to Trippy. His head will get too big and he'll think he's too good to hang around helping people in this forum, and then we'll all be worse off. Just offer him a polite thanks and that's it. We want him to think his awesome solutions are merely "occasionally helpful" and no more than that.

[Claus_J]

OK, I’d like to change my previous comment to “I find your solution passable while waiting for something better” 🙂

[chrisplyler]

That almost works. The only problem is that once Trippy offers his solution, there is a pretty low likelihood of anything better coming along. After a while he would catch on.

[lichtzeichenanlage]

A better solution - so using blender 😉

[Anonymous]

Wow, is the answer really that you have to create a 2D spline/curve and then manipulate it to become 3D? I was really hoping this wasn't the answer - this makes 360 was inferior to NX, imo. And you can't manipulate G0/G1/G2 constraints with other curves...Please tell me I'm missing something?

[TrippyLighting]

@Anonymous Siemens NX vs. Fusion 360 ? G3 curvature continuity ? 

You have got to be kidding!

Have you done some minimum homework and actually compared the history and price tag of the software packages you are comparing ?

That is clearly only one thing you're missing but its a significant one!

[Anonymous]

@TrippyLighting Yeah, actually I have done that homework - which I will say isn't easy. To even get a base price on the most minimal NX package you need to contact a sales rep. The Mach 3 NX 11 package does cost $26k and $5k/year.

BUT with the enormous hype surrounding Fusion I guess I just expected more. Granted the NX package goes far beyond what Fusion is capable of, there are basic functions, like 3D splines, that I would expect any basic CAD software to have. This is where I express my frustration. I use NX for work and I'm trying to learn Fusion for hobby.

There is a specific design I'm trying to work with that is difficult in Fusion, but I can't export it if I use NX at work.

I'm finding complex surfacing an issue. Maybe Inventor is more catered to 3D splines and complex surfacing?

[TrippyLighting]

Nope!

The limitation in both is the  geometric modeling kernel ASM (Autodesk Shape Manager). This is a fork  of the early ACIS kernel.

None of the geometric modeling kernels In main stream CAD software ACIS or Parasolids can create or deal with the higher order surfaces that can be created with Autodesk Alias, NX, ICEM surf, or Catia.

You need 5 degree surfaces to create G3 curvature continuity if I am not mistaken and Parasolids and ACIS can only do 3 degree surfaces, so maximum G2.

Aside from that Fusion 360 lacks a number of tools such as an untrim tool that is essential in surfacing.

Fusion 360 certainly has its strengths ( e.g. building CAM) but surfacing isn’t its strongest suit.