Problem with an automated sweep 1

[mikenelson9]

I am using NX v8 on a Windows 7, 64bit machine.

I am creating a very complex geometry that is much too tedious to do by hand so we used MatLab to write a visual basic script. The geometry is comprised of: a series of profiles that are swept to form a closed loop. Each profile is made of a spline fit to data points. The profiles are then swept along another spline to form a 3D solid body.

We have been doing this for quite some time now without issue but recently I needed to change the shape of the profile from a "flat plate" to a flat plate with an elliptical leading edge. As seen in the attached file, in the geometry with the elliptical LE there are regions where it looks like certain profiles are getting connected wrong during the sweep and became twisted. You can see that the leading and trailing edges are no longer smooth but have twists and oscillations. The original flat plate geometry is also attached showing smooth transitions as expected, as well as the vb scripts. I am somewhat new to NX as well as this forum so if I've omitted important information by accident, please forgive me and let me know what I'm missing.

Does anyone know what could be causing this?

Thank you,
Mike

 

[cowski]

Wow, that's...
something.

In the "without errors" model, you will see that each section spline has exactly 68 segments. The "with errors" model the number of segments varies from spline to spline. The "parameter" alignment option is trying to match each spline segment to segment, which is why you see twist between certain sections (some more than others). You can use the "by points" alignment method to help reduce/eliminate the twist between sections. You might investigate how to use that alignment option in your script or seek to generate splines with the same number of segments.

www.nxjournaling.com

 

[mikenelson9]

Thank you so much cowski for noticing that!! It was the exact problem and was easy enough to fix in my MatLab code. Thank you again!


Mike