I drew our simple post vectors in Aspire. The top cap is just an oval rotated slightly.
I then used the node tool to 'CUT' the outermost vectors on each side of the cap. This, as you may have guessed, will be our 2 sweep rails.
If you look closely, you can see the dotted cross section I drew for the cap. I also rounded the corner edge of it to allow for an easier time blending it with the post body. A smooth, curved join will be less noticeable than a sharp one.
After selecting the top and bottom rails from our cap, then the cross section, voila. A nicely shaped cap with a smooth rounded edge. Make sure to set this component to 'MERGE'. This will let us blend it nicely later, with predictable results.
The next step is to click the 'View along Y axis' button in the top right most corner in the 3d view window, Then select the 'Save shaded view' option from the VIEW menu bar. Give this image a name and location for saving. When done, import this image right back into Aspire. This is the 'perspective free' profile of our cap.
Now we need to trace this outline with the line tool. The easiest way is to draw a straight line from the left side of our component to the right, select the node editing tool, and convert the line to a bezier curve. Then just adjust the curve with the bezier node handles until you are satisfied with the shape. When your happy, you can delete the image as we don't need it anymore.
As our imported image's component size will vary, based upon how close or far we were zoomed in when we saved the image, we need a definitive size. This newly created vector is going to be our cross-section for the post body, so it stands to reason we need a measurement from the post. Using the measuring tool, let's measure the straight span at the top of the post body. Mine measured 4.185".
Now I just select my post cross section and set the size to 4.185" making sure the 'LINK XY' check-box is on. This will keep our profile intact both in length and width.
The next post will cover making the post cap.......as soon as I can finish it!