topic Re: A loft that doesn't loft in Inventor Forum

A loft that doesn't loft

tim.jager2001 — Sun, 21 Apr 2024 17:46:25 GMT

Hi,

I have two sketches that I need to extrude between. Now the outlines and drill holes are identical, but the shaft in the middle shrinks by 1mm towards the bottom and if you look closely, you'll see that part of the bottom holes are also in the outline. In other words, I feel like this is what a loft should be for, connecting differently shaped surfaces, but I can't get it to work.

Any hints as to how I could do this?

Kind regards,

Tim

Re: A loft that doesn't loft

kacper.suchomski — Sun, 21 Apr 2024 19:52:27 GMT

The Loft command only supports one geometry in one operation. If there are multiple geometries, multiple Loft operations must be performed.

Since the outer contour is constant, Extrude will suffice. Then perform a Loft in cutout mode for the shaft geometry.

Re: A loft that doesn't loft

tim.jager2001 — Sun, 21 Apr 2024 20:09:23 GMT

Thank you for the suggestion.

It is something I thought about, but the thing is that the inner contour is quite complex and will in part be covered by the extrude, so I don't know how to solve that part efficiently. Like all the holes and such have to be identical as they now are. Am I missing something?

Re: A loft that doesn't loft

YannickEnrico — Mon, 22 Apr 2024 05:06:18 GMT

The geometry exists in your sketches, doesn't it?

So if the geometry is covered by the first extrude, you can just share your existing sketches, and base a loft (cutout) on them

Re: A loft that doesn't loft

tim.jager2001 — Mon, 22 Apr 2024 11:02:16 GMT

But how does that retain the inner geometry? Like, I have extrudes in multiple directions in there, so wouldn't they either get cut away, or filled in?

I also considered moving the extrude and cut into the past, but the plane to which it goes is based in a cut, so I can't really do the extrude before it.

Re: A loft that doesn't loft

YannickEnrico — Mon, 22 Apr 2024 12:07:55 GMT

I think this is what you're hoping to achieve?

Re: A loft that doesn't loft

tim.jager2001 — Mon, 22 Apr 2024 13:11:34 GMT

That is exactly it! Thank you!

Still having troubles working out how this mechanic works (and how to adjust it, because, as you probably guessed, I completely missed the way it should match on top side). But I think I can work from here.

Re: A loft that doesn't loft

tim.jager2001 — Mon, 22 Apr 2024 15:15:02 GMT

So I thought I got half of the process, so wanted to test if my thoughts were right, but got stuck way too soon. Any idea why Loft6 doesn't re-cut the hole?

Re: A loft that doesn't loft

johnsonshiue — Tue, 23 Apr 2024 00:11:30 GMT

Hi! I am not sure why Loft has to be used here. You could use the profile in the middle to extrude as a solid body in one shot.

Many thanks!

Re: A loft that doesn't loft

YannickEnrico — Tue, 23 Apr 2024 04:09:28 GMT

It doesn't because I made a separate solid (so now there's two solids) to conserve any geometries while I was exploring what you tried to do.

Note how the bottom plate glows turquoise on your screenshot, while the other part glows purple on mine. (different colour scheme is tied to In-Canvas colour scheme in settings)

With multi-body solids you sometimes have to pinpoint what solid you're working on, because Inventor can only make its best guesses based on inputs.

Re: A loft that doesn't loft

tim.jager2001 — Tue, 23 Apr 2024 12:48:06 GMT

It is going from one shape to another, so I don't think that an extrusion is the ideal solution here. I also feel like it is a good learning opportunity.

Re: A loft that doesn't loft

tim.jager2001 — Tue, 23 Apr 2024 12:53:18 GMT

This just cleared all confusion I had. Thank you again!