Hi Steve, like Mike says your method looks like it was fine.

Rail revolve might be another additional option for the upper part - things that look like they have a rounded tip can often be done with revolve or rail revolve.

See here for a kind of similar example:
http://moi3d.com/forum/index.php?webtag=MOI&msg=4374.4


> when defining a rail will having more points defined your 2d
> curve achieve better results?

No - the number of points in the rail doesn't really particularly matter, it's the shape of the rail that matters.

The way sweep works is that it starts with a small number of cross-sections generated along the sweep path, and then builds a surface through those. That surface is tested for accuracy and if it is not accurate enough the sweep gets refined with more cross-sections added, so it's a kind of refining process.

That process doesn't really have much to do with control point structure, the accuracy measurement has to do with sections being generated at different spots along the rails, so it's only the position and direction of the curve that really directly impacts the sweep.

- Michael