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"Top Down" Assembly Problem


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I have created a wing assembly using a "top down" approach. Essentially, I have planes spaced accordingly with airfoil profiles on each. I used these sketches as the "skeleton" of my model, with several features driven by the sketches.


The problem is I need to delete a spline and replace it with another one, and I know that I will lose all the constraints linked to that original spline. Is there a way to avoid losing all the constraints? (I have tried replacing it, and it throws errors due to the original spline being deleted) I am trying to avoid having to go into each feature and redefine the constraints.


Perhaps a solution to this problem would involve changing the name of the new spline to match the original. I have not figured out how to do this (after much research) nor do I know if its possible.


Any help/suggestions is greatly appreciated.

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I'm assuming these sketches are used to create a loft. With out seeing the model, I don't understand why you can't edit the original spline. You can add points, delete points etc... to modify spline to fit. You may need to delete specific constraints to make modifications but once completed you can reapply them. You may encounter rebuild issues, but this should be easy to correct. You can also try making the original spline construction then create new spline using original constraints. I believe changing the name of sketch/feature wont work. What ever you create first would become the parent feature anything linked to that after would become the child. Changing the name wont break this relation. Again, without seeing the model this is my best guess.

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Bill is exactly right. Renaming wont do anything for you. Editing your spline is the only/best way. Any other method will require you to manually edit every sketch.


What do you need to change about the spline? Was this spline added after the planes/2d airfoil profiles? Or was this spline and its points used to define the planes? What constraints were added? Pierce or coincident?

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The splines were converted from curves I inserted that were based off .txt files containing the airfoil points (Insert>>Curve through XYZ points). So essentially I have two different curve entities at the beginning of my assembly. Then I created the planes various distances apart and converted the appropriate curves onto each plane, and resized via an equation to get the chord lengths the way I need them to be. I guess my problem is I can't edit the spline coordinates directly because I converted them from the curve I imported at the beginning. Let me know if this needs clarification.


Also, I used the pierce relationship several times, as well as some coincident constraints.


I went ahead and simply deleted the two splines that I needed to replace and replaced them by converting the new airfoil curve onto the planes and simply redefining the chord lengths, etc. To my surprise....only ONE of the curves lost all the constraints. This confused me as I did the same process for each regarding how I replaced them. How can I get this to happen everytime (if there is a set way of doing it)?


Again, let me know if anything needs clarification.

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If your splines are converted splines you can select them and in the properties box remove the relation(on edge) and this will under define them. since they had several points based on your xyz coordinate you should be able to edit them this way.


The pierce relationship usually updates a little better when modifying curves/edges because it doesnt rely on a specific point. The coincident relations are usually the ones that throw up errors.

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