Loft not following the rails

[Anonymous]

(Inventor Professional 2021)

Hello,

I'm trying to connect two profiles (the flat base of the top body to the profile outlined by 3D Sketch7 on the bottom body) with a loft, and want the loft to follow the 3D splines connecting the profiles' 6 corners to create an organic-looking form. While I'm allowed to do a straight loft, if I select any of the 3D splines as a guide rail the preview disappears and the loft will fail. The curves definitely connect to the profiles' corners and they are tangent to the edges they follow on from, so I thought the loft would work smoothly. Are the angles between the two profiles too extreme? Or the cures to curvy? Any ideas?

(PS apologies for the horrible part name, I don't know what came over me)

Thanks,

Frank

[JDMather]

There are multiple unresolved issues indicated with an i in a circle in the browser.  

I would resolve these issues first (especially 3DSketch2).

[Anonymous]

Thanks for the help @JDMather , I have resolved those issues in the browser, but I still cannot perform the loft, could you tell me how you achieved it? Also the one you did is not exactly what I'm after as I want the loft to go to 3D sketch7 not just the curved faces.

[gmwi · Accepted solution]

I'm not sure if this is what your going for but here it is. That's a bad option for lofting but the surface creation is the way to create the transition.

[Anonymous]

Oh I see, thanks! I have got what I'm after now, just altered some of those curves to make a smoother transition. 

[johnsonshiue]

Hi! Here is another solution using Loft and Bend Part without complicated 3D sketches. Please take a look.

Many thanks!

[gmwi]

That is the way I was thinking of doing it.  Bend is a VERY powerful feature.

[Anonymous]

Wow thank you, I wasn't aware of the bend feature but it's cool. I think I still prefer the surface creation approach with 3D sketches because of the control you get over the flow of the transition, but I'll have to have a mess around with bend and see what I can come up with. Thanks!

[johnsonshiue]

Hi Fank,

Yes, this type of geometry should be modeled using surface modeling tools. The issue here is that Inventor has limited ability to define 3D curves and surfaces due to the tight tolerance requirement. As a user, you will have to find ways around it. Solid and surface modeling are interchangeable. The goal is the same. Sometimes, you can use surfaces to facilitate creating solid bodies, vice versa.

Many thanks!