Revolved surface is not smooth - help

[craigr]

Revolved surface is not smooth - help

Hello,
I would greatly appreciate any advice. In 2D sketch I sketched an ellipse centered at 0,0. I then sketched a vertical line on the y axis I then trimmed away all the lines leaving half of an ellipse. I revolved the 'half ellipse" 360 around the y-axis. The resulting solid has an uneven surface at the start/end of the revolve. Is there any way to make the surface smooth?

Here is an image from a published PDF (uneven surface near center and line going around the solid) :

 

[swertel]

Is it mathematically not smooth, or just graphically?

Have you tried adjusting your arc smoothness value to see if the surface smooths out at all?

Have you done any interrogating of the geometry with any inspection/measure commands to see if it is smooth or not?

Do you have any surfacing programs also installed? You could export this as a step or iges file and use those tools to interrogate the model.

 

[MilesH]

craigr,

Could you upload your Alibre file to the Binaries section, so that we could take a look?

BTW, there is an Elliptical Arc tool.

 

[craigr]

Thank you

Thank you very much for your suggestions. I will try those. I posted the part file and published PDF. So it seems that maybe the uneven surface is not really present but only in the PDF rendering.

Here is the link to the binaries:
http://www.alibre.com/forum/viewtopic.php?p=32759#32759

 

[MilesH]

craigr,

There is a very slight surface irregularity in the Alibre display, too - if you turn up the reflectivity (Color - Properties) you can see it - but, as swertel hints, it's inversely proportional to the tessellation factor and only affects the display mesh.

I think it's just a limitation of the present conversion to PDF but you might like to submit a Support Incident on it.

 

[craigr]

Thank you for your thoughts and quick response.

I posted the drawing file to the binaries section. I noticed a line is visible in the projections where the sketch starts/ends.

I will take a look at the surface irregularity in the Alibre display. I will also try to better understand how to inspect the geometry.

It seems this is a rendering issue.

 

[MilesH]

craigr,

If you want a good illustration:
In Alibre, set your "Minimal Circular Facets" to a low value (say 7 or 8) and look at the way that the displayed surface is treated as it passes through the elliptical profile Sketch.

 

[MilesH]

Re: Thank you for your thoughts and quick response.

I posted the drawing file to the binaries section. I noticed a line is visible in the projections where the sketch starts/ends.

If you uncheck "Tangent Edges" from the View Detailing Options in the Standard Views dialog when you create the drawing, then you don't get the line.