Cannot select sketch plane for offset surface

tom_sorensen

I created a sketch outline of an object (with Use), and I've previously been able to select the Offset Plane tool to turn that into a surface, but when I try with this Part/Surface it simply will not allow me to select the sketch plane. And it's likely related that if I try to extrude the sketch, it will only allow me to extrude the surface, not as a solid. No idea why, as I've extruded as solid with similar sketches before as well.

As best I can tell there is a contiguous loop -- the sketch was created with a single Use action. And if it wasn't, then I couldn't extrude at all.

Doc is https://cad.onshape.com/documents/f2243ac31855ebafb96cc50f/w/0b3073d2c4ef3fd0b9e6824e/e/b03ee2767c8640df13beb944?renderMode=0&uiState=6532ebf124e5ce05edced79b -- The one that's a problem is the 1x2 Ell. The 3x3 Block is one I did earlier and it's working as expected.

wayne_sauder

@tom_sorensen
I believe you might have a point somewhere in your sketch that is not closed. If the sketch is fully enclosed it will be shaded gray.  

tom_sorensen

In searching how to find non-contiguous lines I discovered the Enclose tool, which does work and creates a part. I have no idea why it works and everything else I tried didn't.

You're correct that it's the most likely reason, and the lack of shading indicates that. The most likely cause is the inside corner, which I created. But it seems to be fixed with the Enclose tool.