Constructing a swept solid Please see the .blend file attached.



I want to 'sweep' a profile along a path to create a solid that can then be exported as an stl file for 3d printing. Unfortunately, I have several issues...


the ends of the resulting 'solid' are uncapped. While it's easy to select and alt-F the end vertices, it seems there must be a simpler way
I construct the 'solid' using the bevel modifier. But, regardless of what method I use, I always end up with overlapping meshes - as highlighted in the following image. The resulting stl file has 'bad edges' and I think this may be a reason:





Finally, the resulting mesh seems to have far too many faces, but I can't see an automatic way to reduce this. Again, this results in a large blend file and a huge stl file.


I know it's bad form to post multiple questions, but these are in a way all aspects of the same problem: How to construct a valid stl file.

Anyway, as always, any thoughts on resolving any of the above hugely appreciated.
Let me unpack this one by one :)

1. Fill caps
You need to check Fill Caps in Geometry > Bevel > Fill Caps  



2. Overlapping geometry
This is a result of beveling multiple curves into one point.
You'll have to manually clean it up, or use the Boolean modifier, etc.

3. Too many faces
To adjust the amount of faces change the values in Shape > Preview/render resolution.
You can do this for both of your curve shapes.



Here is the edited .blendfile