I’m lacking knowledge on how best to generate clean closed planar curves for use in extruding solids. Where can those best practices be found?
Please see the following for examples of not so great curves I’ve generated and used to extrude: NACA_2412_Airfoil_07_01_24.3dm (875.3 KB) 4448_Blade_Spar_Profile_06_29_24.3dm (868.2 KB)
Rhino is full of booby traps and the best practice is to learn to avoid them.
A starting point would be to choose a unit system and tolerance that is in proportion for what you are doing. This should be the first step in every model and can be done automatically using templates.
In your file you are trying to draw something that is less than .02 units long.
If you make the units millimeters the part will be about 17 millimeters long. That is more in keeping with best modeling practices.
It is unlikely that you could manufacture your part to an accuracy of better than .01mm so there is little point in using a tolerance a whole lot tighter than that.
The real problem is not the way you make the curves nor is it in extruding those two curves.
The problem is what you do next with those extrusions. You haven’t shown that part but i am pretty sure what you are doing is designed to fail.
Post the model before you try to combine the two extrusions and you may get some help with either that step or how to make the curves so that step will work.
Got it. Thanks for the input. Have taken to heart. This stage of the process is for cfd simulation, not manufacture. Lesson learned here will help with generating meshes for OpenFOAM with the snappyHexMesh utility.