I have done the tutorial where we build a closed cylinder around the membrane.obj file and that all worked fine however when I try to do the same thing with another example I run into a failure.

I had created a long rectangular box with air to flow in one end and out the other. Floating in the middle of it is a flat plate at an angle.

I had created the outer box and plate in Rhino and saved it as a *.stp file. Once loaded into Caedium two volumes were found. (the box and the plate) I then subtract the plate from the box creating a single volume which worked. Then when I go to apply the 2 sided feature to the plate I am issued an error.

Error:
Failed: Create 2 sided geometry

Is there something I have to do to the plate before I can assign it a two sided condition?

Thanks,

Ken