Variable Section Sweep - Section Plane Control

[TomU]

Is there any way to create a variable section sweep with the section parallel to the trajectory? I'm using a circle for the trajectory. To properly create the geometry I need to sketch looking down at the circle, not at a section normal to the curve. See attached pictures. I'm using the trajpar function with a graph, so I believe it has to be a variable section sweep. Thanks.

Tom U.

[cid:image001.png@01CEC66C.4585FE60] [cid:image002.png@01CEC66C.954DE200]

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[DeanLong]

Can I assume the circle on the cylinder is just for convenience? In other words if you sketched a circle on a plane and used that as the origin, would it be the same thing? If you are using a trajpar then I assume you are trying to create some kind of "helical" feature? Not necessarily a true helix but some type of feature that is rising while it's running.

You may be better off creating an explicit drive curve and the start curves, internalcurves (if needed)and ending curves then use boundary surfaces to create the solid. VSS with trajpar is a resultant method of creating geometry whereasdeveloping the geometry gives much more control if the features are not "simple" stuff.

Sketch a picture of the ultimate goal and post it. From there it can be determined what method may work best.

[TomU]

At different points around the trajectory the section needs to occasionally lead or follow the current trajectory position. That's why I wanted the section "looking down" at the plane through the trajectory, not normal to it. (See first picture. Red line would be leading the trajectory position and blue line would be lagging.) This would create a flat, planar surface. The resulting surface would be created at a different "rate" than the trajectory motion, but it would never overlap on itself.

[cid:image002.png@01CEC997.9827E880]

I was trying to create a cam surface compensated for the arm following it. (Cam profile is driven via a graph and the trajpar function.) I was hoping to do this with a single VSS feature. Currently I have to create a point sketch, pattern it 360 times, and then create a sketched spline through the points. (See second picture. Blue curve is desired arm movement - math profile. Red curve is compensated for follower arm length.)

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