new part in assembly: top down

I'm trying to make a new part within an assembly. Insert/component/new part
produces a cube pointer. I can make the sketch but can't extrude it. How
should I do it?

TIA,
Mac

 

Ummm . . . so you Place (drop) the new Part into the Assembly using the
cube pointer (right?), THEN you are automatically in a Sketch on the
Plane (or face) on which you dropped the new part (right?) -- and you
say you're making a sketch there and can't extrude it? Sounds like
maybe you're not quite sure where you are in the process above. Be sure
you've dropped the new Part in first.

 

Thanks,
Apparently I didn't save the assembly and the new part correctly.

 

Usually, we need all components to share a common origin, so all
components are fixed.

The easiest way I have found to place a new component for this case is
to first open and save a new part, then drag that new part to the
assembly. Don't drag the part to the model window. Drag it to the
assembly icon at the top of the model tree. This drops the component
into a position where the origin and orientation are the same as the
assembly.