Unexpected loft default behavior.

[tcrxelizondo]

Hello,

While creating a simple loft, I experienced what I consider to be unexpected loft behavior. To illustrate the problem, I have created two very simple sketches one on top of the other, see screenshot below:

Both circles on the sketches are centered on the origin, they are the same size diameter and the triangle on the upper circle is symmetrical (see attached Fusion 360 file).

I would expect that when creating a loft between the two sketches (using loft default values and behavior) the resulting loft would be a nice symmetrical loft like this:

1

but instead I get this:

This does not seem very intuitive to me. Is this normal loft behavior or am I doing something wrong? No big deal, just curios.

Thanks.

[TheCADWhisperer]

If you do not have the same number of entities in profile sketches - you might need to "help" the software map the points.

[PhilProcarioJr]

@tcrxelizondo

Although I agree this should be easy and work the way you describe it doesn't.

The way I would do this is with 2 lofts, look at the file I attached and roll through the timeline to see how I did it.

Updated the file first one was wrong.

[Anonymous]

Hmm... It's strange, but when I loft that profiles I get it at least symmetrical, that is more or less ok.

[PhilProcarioJr]

@Anonymous

I got that result to and the reason for that is it has some to do with where you select each profile. If your selection is roughly the same location on each profile you get the results you show.

[tcrxelizondo]

@PhilProcarioJr

Thanks for the tip. I have and extra question that I hope you can help me with.

When doing the loft, I see that I am able to drag a couple of rails around, see picture below (active rail shown with red color).

It looks like I could theoretically move the rails around to achieve the same result without having to create multiple lofts. The problem is that the rails end points will not snap to existing geometry (at least I was not able to do that).

Why is that? Can you make this work using the rails instead of the dual lofting? Just curios.

Thanks.

[PhilProcarioJr]

@tcrxelizondo

"It looks like I could theoretically move the rails around to achieve the same result without having to create multiple lofts. The problem is that the rails end points will not snap to existing geometry (at least I was not able to do that).

Why is that? Can you make this work using the rails instead of the dual lofting? Just curios."

You can def just drag the guides and make this work without doing two lofts, but it will not be accurate.

So which way you do it is up to you and the amount of accuracy you require.

As far as the snapping to existing geometry...I run into this all the time...it's probably a bug

@innovatenate Can you see if the snapping issue is a bug or by design?