topic Re: Using Extrude on Circle with embeded elipses included and excludeds elipses at random in Fusion Support Forum

Using Extrude on Circle with embeded elipses included and excludeds elipses at random

jeffpkamp — Wed, 20 Jul 2022 15:25:28 GMT

I have a circle 125mm across, with a second circle offset by 1.25 mm. I put an ellipse 1.475 mm wide and 2.331 mm long with its center point on the inner circle with long axis pointing toward the center of the circle. I use the make circular pattern tool to create 113 of these ellipses with the center of the circle as the rotation point.

I finish my sketch and select all sketch elements and then exclude the center area of the circle (I'm making a belt with teeth). It selects all of the ellipses and the outer ring. However, when I extrude the selection, it randomly does not extrude ellipses

SelectionExtrusion

Selection Looks Like This

Extrusion looks like this:

Re: Using Extrude on Circle with embeded elipses included and excludeds elipses at random

TheCADWhisperer — Wed, 20 Jul 2022 15:36:21 GMT

Pattern features, not sketch elements.
Can you File>Export your *.f3d file to your local drive and then Attach it here to a Reply?

Re: Using Extrude on Circle with embeded elipses included and excludeds elipses at random

jeffpkamp — Wed, 20 Jul 2022 16:25:24 GMT

Here is the file. Making the pattern with the solids did work. It definitely still seems like a bug. It works fine with circles, so I assume there is some sort of calculation error with the ellipses.

Re: Using Extrude on Circle with embeded elipses included and excludeds elipses at random

TheCADWhisperer — Wed, 20 Jul 2022 16:44:28 GMT

@jeffpkamp wrote:
Making the pattern with the solids did work.

I don't know what this means?

You still have pattern in sketch?

Only one ellipse is needed.

It doesn't appear to have worked to me.

Also - your first sketch - the very foundation of your part is not fully defined?

Example of a fully defined sketch...

BTW - the best practices technique of Pattern Feature rather than sketch elements holds true in Autodesk Inventor Professional, SolidWorks and Creo...

Re: Using Extrude on Circle with embeded elipses included and excludeds elipses at random

jeffpkamp — Wed, 20 Jul 2022 17:37:51 GMT

When I said that using the solid pattern worked, I mean I made a single ellipse in the sketch, extruded it to make a body, and then used " solid>create>pattern>circular pattern " to create multiple copies of it around the center of the circle in the sketch and then joined those to the solid ring I had made.

I tried constraining the ellipse in the sketch, but that did not seem to change anything. I am not sure how exactly you made yours. I made the center line of the ellipse tangent to the inner circle, the center of the ellipse was centered on a line that crossed the middle of the inner circle. Got the same results with trying to extrude the sketch.

I now see why patterning the features is a best practice, since using sketch elements leads to double the memory (holding all the sketch objects and features made from them). I will keep this in mind!

Re: Using Extrude on Circle with embeded elipses included and excludeds elipses at random

TheCADWhisperer — Wed, 20 Jul 2022 17:42:00 GMT

@jeffpkamp wrote:
I tried constraining the ellipse in the sketch, but that did not seem to change anything. I am not sure how exactly you made yours.

Ellipse in Fusion 360 is very finicky and not well behaved.

I always create major and minor axis as construction lines first with Midpoint constraint between the two construction lines. Even more trouble if you trim the curve...

Re: Using Extrude on Circle with embeded elipses included and excludeds elipses at random

jeffpkamp — Wed, 20 Jul 2022 17:47:38 GMT

I am really starting to notice just how badly they behave! I had never used ellipses before, and I think I'll probably avoid them in the future if I can. Thank you for your help!

Re: Using Extrude on Circle with embeded elipses included and excludeds elipses at random

TheCADWhisperer — Wed, 20 Jul 2022 17:51:38 GMT

What belt standard are you using?

I don't think this design matches a standard anyhow.