Constraining splines in sketch mode

[andrewR62MC]

Hi, I've started using splines, but don't know how to fully constrain them. Anybody have any thoughts?

[lichtzeichenanlage]

And I assure you I don't give a hoot about what you assure... Adding another perspective but not what I asked for. What a waste of time.

[eduard.kieserCH5R3]

I have a question related to controlling splines. When designing a wing I use a spline to trace some airfoil for both the root and the tip of the wing. I would like the wash-out (twist) of the wing to be controlled by a user defined parameter. In Inventor I would do this using sketch groups. I would trace the airfoil and draw one or two construction lines and would then group all of these sketch elements in one sketch group (similar to a rigid group of bodies). Defining the angle between the airfoil center line (in the sketch group) and some reference line would then be simple. How would I active this in fusion?

[g-andresen]

Hi,

try it with a loft.
Limit the number of profiles to the minimum and create rails that intersect each profile. For the sake of harmony, the rails should have as many control points as necessary but as few as possible.

Please share the file for investigation.

File > export > save as f3d on local drive  > attach it to the next post.

günther

[davebYYPCU]

Best results I got were 4 point Fitted Splines, traced in place, for top and bottom of the airfoil.

Either Loft or Sweep with Path & Guide Rail, dependent on outcome required.

Might help...

[nadovich]

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@TrippyLighting wrote:

So here's a question that might border on heresy for some folks:

Why would you need to fully constrain and dimension a spline?

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So the sketch doesn't suddenly go nuts as the splines all freak out.

[TrippyLighting]

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@nadovich wrote:

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@TrippyLighting wrote:

So here's a question that might border on heresy for some folks:

Why would you need to fully constrain and dimension a spline?

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So the sketch doesn't suddenly go nuts as the splines all freak out.

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In my designs sketches don't suddenly go nuts because the splines freak out. If you have a case that you can share I'd appreciate it. It is quite possible that there is buggy behavior at play and I'd be happy to report that as a bug.