I'm again working on a new and bigger Windsor - one that is typical of those in Philadelphia in 1776. I found a design in Lester Margon's "More American Furniture Treasures", a fan-back with greatly raked legs.

While working up my SketchUp design, I was surprised in the design and positioning of the Top Rail. The surprise was how the Top Rail is horizontal as viewed in a front view. In my first attempt in making and placing the Top Rail in SketchUp, I saw the "surprise" with the ends of the Top Rail drifting upward away from horizontal. I couldn't figure out what was wrong and began to review pictures or other fan-back Windsors. I found some Top Rails did indeed rise up toward the ends. But I also saw examples with a flat horizontal Top Rail. So I began to develop a way of making this flat horizontal Top Rail which is shown below.

Here is an orthographic front and side view of the fan-back Windsor. This view is made from my incomplete SketchUp model with "parallel projection".  Notice the flatness of the Top Rail from ear-to-ear. If you simply bend a Top Rail and then rotate to line up with the recline of the back, the Top Rail will rise up at the ends when viewed in a front view. This fan-back is made without this rise toward the ends, so a simple bend will not work.

Step 1: I scanned the Margon drawings and imported into SketchUp. I then proceeded with the tracing-over of various components. Below are the trace-overs of the top and front views of the Top Rail (only one half the length).

Step 2: In this step I'm using both of these shapes from above in preparation of an Intersection used later in the process.

Step 3: If I arrange the components above such that I'm looking straight on in parallel projection, I can see how the "canted" rail piece in the back creates a rise above horizontal toward the end. Also, note how I've positioned the front face to be totally within the boundaries of the rear piece.

Step 4: In this step I am performing an Intersection of these two shapes.

Step 5: Here is the half-rail after the intersection and clean-up.

Step 6: I copy the half-rail, and combine with the other half rail to make the whole.

Step 7: Here is the "horizontal" Top Rail in place.

I have more design work to complete the spindles and shape the seat, but the hard part is done. However, I'm still not sure how I am going to bend and construct this Top Rail. I'm thinking to do a simple bend, then do the arc shaping after the bend.

Tim
http://killenwood.com