Hi SurlyBird, that shortcut that Burr shows above helps out a lot to locate the areas that are have open edges.
> I got it to work one time, but subsequent attempts to repeat
> it have failed. I get a good sweep, but when I try to make a solid
> by joining the pieces, I get a joined surface as a result.
You may have fixed just one area and not all of them yet - it looks like there are about 4 or 5 areas in the model that have open edges, if you set up that shortcut that Burr posted and run it they will highlight.
Looking more closely at one of those problem edges here:
If you zoom in to that area closely you can see there is some space between the edges there:
Looking at the bottom surface, it appears to be a surface of extrusion. Probably what happened here is the extrusion is coming from this curve back here:
And that curve from back there does not exactly align with the other curve that has been used to make the front face of the model.
To make an extrusion join up with something else like that, they have to have a very precise alignment between them.
Otherwise, instead of using extrude for that bottom piece for example you could use Network or Sweep, which constructs a surface that hugs all of those boundary curves rather than only being defined by the shape of the curve on one side like an extrusion.
For these ones here, there is a simliar gap:
To fix those, delete those half-circle like surfaces, then select these 2 edges:
and run Construct > Loft to build a surface between them. That can then be joined in to solve those ones.
- Michael
EDIT: Ooops, looks like Burr beat me to it, this is mostly a repeat of what Burr wrote above.