MAKING THE ROCKERS

Determining the right shape for a rocking chair’s rockers, also known as runners, is an exercise in experimen­tation and intuition. When designing a new chair, some chair makers try varia­tions on a basic curve until they arrive at a design that is pleasing to the eye.

To ensure stability, however, the rock­ers must do more than look good. As a starting point, use a radius of 36 inches to 40 inches to draw the curve of the rocker. This curve is related to the height

A laminated rocker is smoothed on an oscillating spindle sander. Laminated rockers, like the one shown at left, offer several advantages over rockers cut from solid wood. They can be made from nar­rower stock, which minimizes waste. They can also be made thinner since the strength of the glue bonding the strips together parallels the grain.

of the chair’s seat off the floor and the height of the person sitting in the chair: The higher off the ground the seat is, and the taller the chair’s user, the larger the arc of the rocker should be. Remember that the tighter the curve, the faster the chair will rock.

In addition to the rockers’ primary curve, you can incorporate a reverse curve at the back end of the rocker, as shown in the chair on page 127. The reverse curve should be gentle, however; if the end of the rocker is not above the bottom of the rocker’s primary curve, the chair will not rock properly.

Rockers can either be cut from a sin­gle piece of stock (below), or laminated from %-inch-wide strips of resawn stock glued together in a bending form (page 130). Resawing on the table saw with a sharp, carbide-tipped blade will yield precise results without the need for sand­ing afterwards.

USING A TEMPLATE

1 Designing the bottom edge of the rockers To make a template for the rockers, cut a piece of plywood or hardboard to the length of the rockers—in this case, about 34 inches. Then cut a thin strip of springy wood to the same length as the template. Using a C clamp and a stop block, secure the strip on edge to one end of the template. Then gently bend the strip into a curve that looks suitable for your rocker, securing the piece of wood in place with clamps and a stop block as shown. (You can using an existing rocking chair as a guide.) If you are including a reverse curve at the back end of the rockers, as shown at right, make sure the back end of the strip is at least 1 inch above the bottom of the curve. Clamping the strip firmly in place, run a pencil along it to define the rocker’s bottom edge.

Bottom of curve

Wood atrip

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Reverae curve

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2 Cutting the template

On your band saw, cut the template along the line you marked in step 1 and sand the cut edge smooth. To complete the outline of the rockers, mark a line that is parallel to the cut edge, spacing the line from the edge according to the desired height of the rockers. Round the outline at the front end and taper it slightly at the back. Bevel the back end of the out­line by joining the line and the edge of the template with a straight line (right). Cut out the template on the band saw.

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Cutting the rockers

Set the template on each of your rocker blanks in turn, making sure the template runs along the length of wood grain on the stock. Outline the template on the blank with a pencil (left), then cut away most of the waste on the band saw. Shape the rockers to their final size on a router table as you would for the rear legs of a frame chair (page 31).

BENDING LAMINATED STRIPS

1 Making the bending form To bend the wood strips that will make up the rockers, build a bending form from two pieces of 114-inch-thick stock (right, top). The desired shape of the rocker’s top and bottom edges is cut into the edges of the pieces of the form, then the strips are clamped in the form as they are glued together, bending the strips to the desired shape. Make the first piece of the form by marking the bottom edge of the rockers on it as you would if using a template (page 128). Cut the piece along the curve and sand the cut edge. To make the second, or fixed, piece of the form, mark the same curve along it, then cut the strips—typi­cally % inch thick—that will make up the rocker. Butt the strips face to face and measure their combined thickness; this will be the height of the rockers. Mark another line on the second piece, using your measurement to space the two lines (right, bottom). Cut the fixed piece of the form along this line and sand the cut edge. Apply a thin coat of wax on the cut edges of both halves of the form to prevent the stock from stick­ing to them, then screw the fixed piece of the form to a base of %-inch plywood and mark the middle of the curve on it with a pencil.

BENDING FORM

Middle of curve

Outline for rockers’ bottom edge

Outline for rockers top edge

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2 Gluing up and bending the rockers

Line the inside of the bending form with wax paper. Butt the strips for one rocker together and mark a line across their center. Spread glue on one side of each strip and butt them together again, lining up the center marks. Set the strips against the fixed half of the bending form, aligning the center marks on the form and the lamination. Butt the other half of the form against the strips and push it to bend the strips slightly. Install a bar clamp across the middle of the bend then, working from the middle toward the ends of the rocker, bend and secure the lamination with bar clamps, tightening each one in turn until there are no gaps along the rocker (right). Let the lamina­tion cure for 8 to 10 hours, then repeat for the other rocker.

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Jointing the rocker

Once the lamination is dry, remove it from the form, scrape away any excess glue, and joint one edge. Slowly feed the workpiece across the cutters with push blocks, applying pressure on the infeed side of the fence with your hands clear of the knives (left). Once one hand reach­es the outfeed table, shift pressure to the outfeed table. Continue applying pressure just to the outfeed side of the knives until the edge is jointed, then pass the rocker through a thickness planer to clean up its other edge. Cut the ends of the rocker on the band saw.