3D spline

Sorry, man, I've been through this whole thread three times, don't see 'blue spline' anywhere (not enough pot, maybe). WTF were you quoting (name, date, subject, interstial 4 dimensional origin)? Maybe something I blocked!?!

David Janes

I get it tyhat you need only a single trajectory for a 'VSS', but then why is THIS a VSS if you can't vary the section? On, yes, you may not vary the section with a single trajectory. That was what the second and third trajectories were for, to vary the section along those trajectories.

What are you referencing with this angle? Sorry, we're talking about an elipse. When sketched, it goes n/s or e/w, along the orientation lines (dashed vertical/horizontal) of the sketch plane. I've tried centerlines and other modifying references for an elipse. Nothing changes its orientation.

Tranpar can control only what's controllable; the ellipse shape (or rather, orientation) is not controllable. If you think so, please demonstrate.

I do not lack the flicker, merely the wattage to reveal the detail.

David Janes

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HTH

Is there a good reason to not use VSS if you want a constant section? It is "the" sweep function with dashboard interface (at least up to WF2, WF3?), dirt simple to set up, etc.

(pictured) volute portion is a VSS using a single arc as trajectory, driving the section (four curves) with trajpar. (I ~think~ the entire shape could have been done as a single VSS, a circle traj and evalgraph(s), but that wasn't the object of the game.)

True. The sketcher ellipse is (?) a special case, but there's a way to get the shape...

_ Start a VSS, selecting a single trajectory. Let's use a circle. _ Create a pair of perpendicular centerlines coincident to origin point, at some angular displacement relative the X and Y sketcher references. _ On those centerlines, place four points to define Rx, Ry (plus and minus, symmetric about the origin). _ Connect the four points with four conic arcs. _ Constrain each conic arc tangent direction perpendicular to the centerlines. _ Tools -> Relations: __ The dim controlling centerline angle = 0 + trajpar * 360. __ Rho for each conic arc = sqrt(2)-1, OK. _ Complete the feature.

You've got a torid with rotating elliptical section. The only difference between that and using a sketcher ellipse will be two additional seam (two sided) edges on the Y axis. (It takes less time to do than to describe.)

I believe there are a lot of VSS tutorials floating about.

the only one that I could remember the location. Web search for pro/e "variable section sweep" | vss tutorial turns of a lot of hits.

Thanks, I guess I didn't actually go through the WHOLE thread (why wouldn't I have thought to look at the first post?) three times.