Designing the Weeks Rocking Chair

No one seems to know who made the first rocking chair.  I state in print that the Weeks Rocker is an original design not because it is the first rocking chair but because I solved the problems of function, construction, and decoration in my own way.  I established my own criteria, my own set of solutions, and my own decorative motifs.

Over a period of a decade, more or less, 1980-90, I studied many examples of chair making, mostly the extremely well-designed, well-built, and well-priced Scandinavian furniture that was imported during those years.  I also read everything I could find.  I remember reading an article somewhere on how to design a chair.  This article claimed to give specific dimensions and relationships for building a comfortable chair.  I built a Presider's Chair, precisely following the article's advice, for an Episcopal priest as part of an extensive interior woodworking contract.  It was torture to sit in.  But pretty good for the purpose — there is no way anyone will ever nod off in front of that congregation.  I learned to exercise and trust my own design instincts.

In 1992 I built a contraption in the middle of the shop.  The contraption was somewhat recognizable as a place to sit; I invited many to do so.  Many sat over many days.  Various elements of this device were adjustable.  I would adjust, the sitters would comment, "Too high," "Too low," "No," " Yes," "Can you . . . "  We came to a collection of adjustments — determining a set of points.  I plotted this constellation of points, full size, on my drawing board in three views: front, side, and down.  Because of the converging lines and curves determined by the points, each view became a set of section drawings.  I designed a chair around these points, refining the curves and contours to suit my eye and to conform to available lumber.  I did not pursue a style.  I was influenced by my influences.  But I copied no one.

These were my design criteria:

Comfort

I wanted to build rocking chairs that a new mother or father could rock in for hours in the middle of the night and feel as softly enfolded as the infant in their arms.

Longevity

I wanted to build rocking chairs to last for generations, the parts large enough in section to hold the greatest potential load (this is the load of abuse, not the load of use) and the joints strong enough to withstand the same overloading.  We use mortise and tenon joinery at the crucial loading points — often passing the tenon through the mortised part and wedging it like an ax handle.  We use screws, countersunk and covered by plugs, to reinforce and secure the glue bond in interlocking or doweled joints.  We never use screws as the sole fastener.

Beauty

I wanted to build beautiful rocking chairs.  Here we leave solid ground.  While there are generally agreed upon visual elements of a work of art, they are hard to measure.  These elements are taught in school or, being hard to measure, taught around.  They include composition, balance, and harmony — and, more narrowly, light, color, form, texture, and value.  All I can say is that, while designing my rocking chair, I considered these things and how they looked, and felt, to me.  There are two dimensions to this criterion.  One, the chair must be beautiful in itself, even if it were extruded from resin and painted black.  Two, the figure, color, and character of the wood must be reverently and delightfully displayed within the form of the chair.

Efficiency

I wanted to build handmade rocking chairs equal in beauty, construction, fit, and finish to the furniture of any studio furniture shop, sell them for less than comparable quality would cost anywhere else, and deliver them in less lead time.  Therefore, the design process included much consideration of the construction process.

How can the parts be developed from available lumber?

Can I build a tool, jig, fixture, or machine to perform this task quicker, better, quieter, cleaner, or with less stress?

Where can I apply the work of the hand and eye to the greatest effect and the most benefit to my patrons?

I fulfilled my design criteria.  The response of people to the comfort, beauty, and construction of the rocking chair has inspired my guarantee.  The Weeks Rocker is guaranteed to be the most comfortable, the most beautiful, and the best constructed rocking chair that you have ever experienced, or you may return it for a full refund including shipping both ways.  In addition the Weeks Rocker is guaranteed against defects in materials and workmanship for the life of the purchaser.

The Design Process Illustrated

How did I design the Weeks Rocker?  Solving the problem of supporting the lumbar illustrates the process.

I had the vertical back curve, defined by the points on the contraption, drawn in side view on a centerline section taken front to back.  I had the horizontal back curve drawn in plan view at head and seat level.  I had my four criteria and my accumulated experience.  These were the givens.

I decided to use the lower muscles of the back as user supplied padding — two vertical muscles, therefore, two vertical splats.  I tried two splats, centered in the seat, each about the width of a lower back muscle, and the two about as far apart as those muscles are.  Any projecting vertebrae could then fall between.  I thought I might use just two splats, but a trial showed that more support at the shoulders was needed, so I added two more.  I considered six, but the outside two were potentially a bother to some shoulder blades.  Besides, I liked the look of four and the resulting space between the splats and the back legs.

I settled on a 1/2" thickness for the splats, thick enough to hold, thin enough to be visually light.  A 2" thick piece of wood of at least 4" in width will make a blank from which four splats can be efficiently cut.  Selecting flat sawn wood for the blank, the growth rings will be perpendicular to the face of each splat.  This is the strongest orientation of grain and displays the most pleasing lines in the overall composition of wood figure in the chair.

The drawings showed that a tangent to the back curve intersected the plane of the seat at 7-1/2 degrees and entered the crest rail (headrest) parallel to its face.  To adequately secure them at both places using my tooling, I chose to round the edges of the splats to half circles and mortise them deeply into their receiving parts with a plunge router guided by a bushing and a shop built fixture.  The splats were clunky looking so I tapered them — making them about a quarter inch narrower at the bottom than at the top.

I solved every problem similarly:  draw, think, draw, try — rethink, redraw, retry.  I made a rocking chair.  Many people sat.  I made minor changes until I thought it was right in fit and detail and construction.  I knew it was right when I got a card from Elizabeth Forbus who received #6 as a gift.  She wrote, "The rocking chair is a perfect blend of art and engineering."