- Skis and chair base
- Why avoid big details
- Comfortable seat with armrests
- Chair assembly, connection methods
- Sewing the seat
After a busy day, you have a well-deserved rest. For complete comfort and peace, we recommend getting a rocking chair. You do not need to buy, we offer detailed instructions for the manufacture and assembly of parts for a comfortable and light chair made of ordinary plywood.
Skis and chair base
The main highlight of the rocking chair is the optimally selected shape of the skis with a constant radius, so that the chair takes a natural position under the load of the human body, does not tip over and at the same time remains compact enough. We propose to make it according to a very technological scheme with the possibility of adjustment.
The details for the left and right sides of the chair are cut and processed in pairs, which guarantees a complete identity of the shape. Before you start cutting, make cardboard templates and patterns, according to which you will mark the blanks. This will not only simplify the process and give a visual idea of the design of the product, but also allow you to divide large elements into several small parts, while maintaining smooth mates..
To obtain the optimal fillet radius, we need an arc, or rather, a sixth of a circle with a radius of 1.5-2 meters, depending on the desired dimensions. We build an equilateral triangle with the indicated side length, and then with a pencil on a string we connect its two vertices with an arc, taking the third as the center. We retreat into the sector a fourth of the radius and draw another arc.
The resulting detail is nothing more than the shape of the skis, but so far they look too clumsy and cumbersome. Since this detail does not have to be massive, at the upper corners we lay off rounded cutouts with a compass and mark the same cut in the center. You can lighten skis, like any large part of the chair, with perforations or cutouts, but keep the whole parts at least 60-80 mm, and at the joints – 100 mm.
For skis, it is also necessary to make a small addition – a bar in the back, limiting the blockage of the chair back.
Why avoid big details
In typical plywood rocker designs, the side members are solid. This approach is not only wasteful but also detrimental to ergonomics. By dividing the parts into a number of smaller ones, you get the opportunity to adjust the chair during the assembly process. Also, the presence of joints will make the chair more springy and pleasantly squeaky, while the one-piece base will convey to the seated person all floor defects in detail..
It is recommended to use thin plywood. Several (5–6) parts 8–9 mm thick are folded in the manner of a Gall chain and connected with ploughshare bolts, thus achieving high strength and maintaining elasticity. In general, in addition to the ski itself, three more parts are included in the basis of the chair.
The seat stock is an L-shaped part half the radius of the rounding (70–80 cm) and about a quarter of its height (40–50 cm). The upper edge has a bend that determines the shape of the seat, the rounding of the lower protrusion is associated with the radius of the ski.
The back is a plank 80–100 cm long and 12–15 cm wide. The bend on the side edge determines the shape of the back surface: in the lumbar region, the seat should have a small recess. Also, since the straight position of the neck cannot be called comfortable, the back should have a smooth turn, starting 50-60 cm from the seat. Bending the edge or wrap it in is a matter of your sole preference.
The shock absorber is a part of any shape, it is convenient to make it from scrap. The main task is to connect the back and the ski, that is, the length of the bar is about 35-40 cm. Remember, however, that the crescent-shaped shock absorber will make the chair softer.
When making templates, lay them out on the table in the form of a finished structure, adjust the shape of the mates and provide a sufficient width of intersecting sections – 100–150 mm. Please note that only one hole is drilled in the details during their manufacture for each attachment point. In places where pairing is required, a second hole is drilled after preliminary assembly and adjustment of the chair, then a second bolt is inserted for final fixation. But back to making parts.
Comfortable seat with armrests
The second version of the assembly offers a more ergonomic design with the ability to adjust not only the angle of inclination of the backrest, but also the “failure” of the seat and its general inclination. Here is a very important point: when drawing up the chair layout, take into account the order in which the parts are folded, otherwise an overlap will result. For example, in both proposed designs the number of parts is odd, conditionally external by one more than internal.
It remains to mention two more small details that form the armrest. An external bracket is attached to the conditionally internal part, which serves as a continuation of the ski. It serves as a transitional element to prevent incorrect assembly order. The second detail is the armrest itself. Its upper edge is absolutely flat, this is done to firmly secure the horizontal plank.
It remains to decide on the number of manufactured parts. In general, each half of the chair is a “sandwich” of 5 parts, folded in a different order. The functional parts of the chair – ski, seat and backrest – are assembled from three parts. Conventionally, internal parts, such as a shock absorber and an armrest, are made two for each half, that is, four for the chair.
An example of cutting a sheet: 1 – back; 2 – addition of skis; 3 – shock absorber; 4 – ski; 5 – armrest bracket; 6 – armrest; 7 – seat stock
After cutting the stacks of parts, they are disassembled, and each is cleaned of chips and irregularities with an emery cloth. It is useful to cut out washers with a diameter of 60-100 mm from the scraps in order to use them to make filler inserts for long parts and to logically complete the protruding parts of the chair – the back and the blockage stop.
Chair assembly, connection methods
The first step is to assemble the ski with the front and rear inner parts. Start the plow bolt from the outside, from the inside, slightly tighten the parts under the washer with a nut with a plastic spring. Then roll the ski on a flat surface to align the mates of the parts, or remove rough irregularities with a plane. Tighten the bolts, drill additional holes, and finally secure the chair support.
Lay the chair blank on its side and attach the shock absorber to it without tightening. Assemble the back and seat parts as well. Shape the chair by eye and tighten the bolts. Having assembled the first half, circle it on a sheet of plywood and, according to the resulting pattern, assemble the second one, the bolts must be tightened halfway until the mobility of the joints is eliminated.
To fasten the halves of the chair, prepare the required number of crossbars – pieces of 40×40 bar with a chamfer on the edges or round timber with a diameter of 40 mm. The length of the beams is 50–55 cm, but keep in mind that when connecting on conditionally internal elements, you must give an allowance for the thickness of the plywood. Make holes in the center of the ends and screw the fittings for the M8 bolt.
When joining, fill the spaces between the layers with plywood inserts. Stamp 5-6 thin slats on the seat and back to get a ready-made prototype of the chair. Test it for convenience and ergonomics, adjust by loosening the bolts on the connections. After getting the desired shape, tighten the bolts so that the caps and washers dig 1 mm into the plywood, drill additional holes and complete the final fastening.
Sewing the seat
Prepare a strip of 5 mm plywood 50–55 cm wide. Measure the total length of the seat and back with a thread, transfer the size to the workpiece. In the same way, measure and mark the cutouts for the armrest parts. Cut out pockets at the edges of the part, then with a 45 mm crown make staggered holes over the entire surface of the part with an indent between them of about 150-180 mm.
Place the piece on a spread wet rag and cover with a second layer of fabric. Lay another piece of the same kind on top, but already made of 3 mm plywood and without holes, but with cutouts for the armrests. Cover with a wet cloth and leave for a day, periodically water can be added.
The next day, take a piece of thin plywood, put it into the niches of the armrests and screw it into the end of the plywood sidewalls with self-tapping screws. Attach to those layers of plywood that are closer to the center of the chair. To screw on thin plywood, start from the back of the chair, gradually moving towards its front and giving the desired shape. Then, in the same way, wind and secure the perforated piece of thick plywood. After drying, the chair will be almost ready.
You just have to dry the plywood well, and then go over all the visible details with a fine sandpaper and lighten the texture of the wood. The chair is then covered with two or three layers of yacht polyurethane varnish. As for the seat, you can even make it soft by stuffing a carriage tie according to our instructions..