Rhino Modeling Problem


I am just starting out with Rhino, so need a little help here. Been thinking about this simple solid for like 5 hours and concluded that it cannot be done. Some one show me how.

Here is what I want to make, and I want to make it accurate and smooth as possible. The two ends are rounded, also the cross section is a semi-circle shape and not a rectangle.

Does this object require multiple steps?
If so, joining of object would lead to unsmooth surface, which i dont want.

Moved from sketching forum

I did the shape you have sketched out (as I interpreted it, anyway) in two steps.

Screen Shot #1
Screen Shot #2

1 - I used lines to outline the shape and define the cross sections. The line that is highlighted was used for a 1-rail sweep with the semi-circles being the cross sections. This gives you the top half of the shape.

2 - The bottom half is created by using the ‘planar curves’ surface tool. You’ll have to create the outlines of the underside of the top half and join the perimiter each plane as a separate box.

I moved the top half off to the side for clarity, but this should give you the basic idea. Join the top and bottom half and you will have your solid.

You can also create a basic solid and trim it to the final shape with simple extruded sections that are the opposite of what you want and trim it with the ‘difference’ and ‘intersection’ tools under the solids menu. Ver. 3.0 seems to have some problems with the boolean tools where 2.0 didn’t, so it may not work as easily as the surfaces. Alternatively, you can draw the outline of the shape in three planes (front, top, side) and, if lined up, can be extruded slightly beyond their intersection point and trimmed to the final shape with the boolean intersection.

Thank you 73lotus, that was very helpfull.

You are welcome.

I am a bigenner, I like rhino