topic Re: Loft Self-Intersects in Fusion Design, Validate & Document Forum

Loft Self-Intersects

Anonymous — Thu, 10 Jun 2021 19:28:50 GMT

I don't understand how this loft self-intersects. It's not yellow. I've tried looking up this issue, but I lack the knowledge to understand people's files I didn't design, and the posted solutions. I solved the "rail tangents not smooth issue", but I can't figure this out. I've been working on it a while. Can anyone help?

I've attached the file not to be presumptuous, but because someone asked for it right away last time.

Re: Loft Self-Intersects

jeff_strater — Thu, 10 Jun 2021 19:45:30 GMT

I'm assuming these are the profiles you are trying to use. You can see that even before I try to select the upper rail, you can see that the surface is wrinkling, and if you try to pull it up more with the rail, it will start to self-intersect:

Re: Loft Self-Intersects

TrippyLighting — Thu, 10 Jun 2021 19:47:18 GMT

The use of control point splines is completely unnecessary to crate this loft and they are also used incorrectly.

Extrude the 1st 30 mm and then loft between the extruded edge the the large profile. Use the sketch radii as loft rails.

Re: Loft Self-Intersects

TrippyLighting — Thu, 10 Jun 2021 19:57:27 GMT

If you really do want to use control point splines then that can also be done. Pay attention to the settings in the loft dialogue!

Re: Loft Self-Intersects

Anonymous — Thu, 10 Jun 2021 21:03:25 GMT

I got that error a few hours ago. I fixed it, then I moved the second profile up a few mm, and got this "intersecting" error business. Sorry, maybe I am dense but I don't see how showing me a loft with a dent that I nobody would want in the design is supposed to help.

Re: Loft Self-Intersects

Anonymous — Thu, 10 Jun 2021 21:09:07 GMT

I'm trying your way, or what I interpret to be your way, and it does not work. I want the adapter segment to be the same OD as the base segment (those two are separated by the "notch") - but with thinner walls. To do that, I don't see how I can use a solid extrude, so I used a surface one. The loft worked without the rails, but then got angry with me when I tried to use them.

I also don't see how I am supposed to know how to use loft from the info graphic and the dialog box. They provide little info, in most cases don't explain what something does, and error messages are rarely helpful to me. Maybe I'm just ignorant.

Re: Loft Self-Intersects

TrippyLighting — Thu, 10 Jun 2021 21:13:05 GMT

I had designs attached to the last two posts. I trust your abilities in Fusion 360 are well enough developed to download them and analyze the timeline.

The nature of my posts aimed at increasing you level of understating the different possibilities of the loft tool, not to complete your design.

Re: Loft Self-Intersects

Anonymous — Thu, 10 Jun 2021 21:26:56 GMT

I didn't download them. Just read what you said, and tried to implement it. After 5 more errors, I got it to work, and I think it's working 100% the way I want. Had to fix rails that didn't touch the profile a bunch, because I've never seen it tell me all the errors at once.

I was definitely not looking for you to complete my design...it's far from done. It's a utility attachment for my resin printer, and this is only part of it. Just needed that one part I absolutely can't get after 4 hours on the loft.

I'll go back and look at your files. Now that I've done it, I can look at how you did it and see if I can pick up tips to improve. That's what I do with Brad Tillis. Thank you.