Simple lofting - can't figure it out!

[laukejas]

Hello again,

 

I'm trying to loft two 3d Polylines and some splines into Solid.

 

It should be very simple, I have two closed polylines above each other (planar), and two splines that connect two points on each of these polylines. I loft, select polylines as cross sections, and select splines as guides. However, the resulting shape is somehow weird, and goes out of boundaries.

 

I'm attaching my project file, please try lofting these two 3d Polylines using splines as guides, and you'll see what I mean.

 

How do I make final Solid to stay in boundaries of splines?

 

I would very much appreciate any help, I'm stuck here for hours.

24.dwg

[ReMark]

What is it supposed to be?

 

I have something but I'm not sure what the heck I'm looking at so I don't know if it is right.

[ReMark]

My feeble attempt.

 

I give up. I have other things to work on. Good luck.

[laukejas]

It's supposed to be a keel of a sailboat. More precisely, half of it.

 

Attaching image it generated by other program.

 

[ReMark]

Then I believe mine is wrong.

[laukejas]

Can't tell from the screenshot, but I guess it's wrong. Something similar happens to me. It should result in the shape I uploaded in my previous post, the red one.

[JD Mather]

Your spline has too many points and your polylines should be splines.

[laukejas]

Could you please tell more? How many is too many?

[JD Mather]

The best curve is only two points with the software interpolating the curve between.

I'm not really familiar with AutoCAD anymore - but check the Curves tab in the Surface environment in the 3D Modeling workspace.

 

In Autodesk Inventor I created two points and than manipulated the point handles to get this curve.

The entire subject gets more involved than can be covered in an online forum - you just need to experiment to pick it up on your own.

 

This image looks pixelated - but that is just my monitor screen capture, the curve is smooth.