Trouble extruding a parametric curve

[Anonymous]

I am trying to extrude the shape which I have made a 2D Sketch of, as seen. The end goal is to create a ramp of sorts, however I think the curve is causing some issues. It is a curve created from a the parametric equation

x: t-sin(t)

y: 1-cos(t)

I have tried extruding, revolving, lofting, free forming, and sweeping but every time I try I get the error "the attempted operation did not produce a meaningful result" I have checked in the sketch doctor which finds no problems, so I am at a loss. Any help would be appreciated!

[jhackney1972]

Please attach your part to your question so others can help.  An equation curve will normally only create a single sketch entity.  Your screen capture seems to show a curve box of some type.  You can extrude a single sketch but it will be a surface only, not a solid.

[Anonymous]

I have now attached the file with my part. If the curve can only be a surface, does that mean there is no way to create a ramp with that specific curvature? Thanks for your quick reply! 

[jhackney1972 · Accepted solution]

Your equation curve is not planar.  If you look at the 'Transformation" values, you will see a slight rotation.  I point this out in the screencast.  The solution is quick, unless you want to try and figure out the correct equation curve, create a new plane above the sketch plane, and project all the geometry.  This removes the rotation value from the equation curve.

Take a look at the screencast and you will understand.

[johnsonshiue]

Hi John,

Many thanks for providing the alternative solution! I am surprised that the 2D curve is not planar. It should not be the case. I suspect there is a singularity on the equation driven curve prohibiting the profile to be created properly. Somehow, projecting it as a reference curve "fixes" it. I need to take a closer look. Something is wrong here.

Thanks again!

[johnsonshiue]

Hi! Indeed, this does not look right to me. It should work. Besides John's workflow, you could also use Boundary Patch command to create a patch surface. Then use Thicken command or project the surface loop and create an extrusion.

Many thanks!

[Anonymous]

Awesome. Thank you all!

[Xun.Zhang]

Share a quick update, it was tracked by ticket INVGEN-8828.

[BRUND]

Just wanted to say thanks for the post.  I find it pretty odd that your equation curve wasn't planer.  I did an involute curve equation and I would have expected a planer result too.  I would be interested in a more in depth answer.

[johnsonshiue]

Hi! Any 2D sketch is planar. The reason why this particular case fails to extrude is due to some high curvature area on the curve that cannot form a profile properly. Unfortunately, the defect INVGEN-8828 was closed as a limitation. I don't see a simple fix to this case.

But, I am not sure if your case is the same as this one. If possible, please share the file here or send it to me directly johnson.shiue@autodesk.com. I can help take a look to see if the issue is the same and also if there...

Many thanks!