This piece of furniture has been conceived for the One Board contest; therefore, all its parts have been made of one single plywood sheet. The chair is for a 4 … 5 yrs old child; however, this design could be adapted for older persons. The principal dimensions are: the seat’s height 312 mm, the seat’s dimensions 300 (width) x 260 (depth) mm, the height of the writing pad 490 mm.

Supplies

Materials

- 920 x 620 mm sheet of 12 mm thick plywood

- short piece of hardwood rod 10 mm in diameter

- three 3 x 30 mm screws for wood

Tools

To mark the parts : ruler, pencil

To cut the plywood and chisel out the grooves : clamps, saw for wood, chisel, hammer, sharp knife like Exacto, drill with 6 mm and 10 mm diameter bits, hardwood bar 20 x 10 mm with sandpaper 80 glued on the bar

Note : it’s highly advisable to put a thick wood board under the sheet of plywood when drilling and chiseling it to protect the workbench.

To sandpaper the surfaces : wood bars with sandpaper 80 and 120 glued on them

For assembly and painting : Paint brush, glue brush, small paint roller.

Consumables

Wood glue, acrylic paint

Step 1: Marking the Sheet

The marking is shown in the picture. The parts to be manufactured are distributed on the sheet as follows :

1 - seat

2 - backrest

3 - armrest and latch

4,5 - side panels

6 - writing pad’s top

7 - crossbar

8 - upper and bottom parts of writing pad’s bracket

Note : the marks are made on the exterior side of the parts; therefore, care should be taken to avoid chipping when you saw and, especially, chisel the plywood.

Step 2: Cutting the Sheet

Lines beginning at the edge of the sheet will be sawed as usual. The diagonal cut between the parts 4 and 5 could be made as follows :

mark a groove at the beginning of the cut; the saw will be inserted into this groove
drill two 6 mm holes at both ends of the future groove
chisel out the groove
insert the saw into the groove and cut the line

The ready parts are shown in the picture.

Step 3: Side Panel

The drawing of the part is shown in the picture. The projections will be marked accordingly to and made as follows :

saw the lines beginning at the edge of the part while making an allowance for sandpapering
cut the upper layer of the plywood (use a sharp knife) at the lines between the projections
chisel out the material between the projections while making an allowance for sandpapering
after you have finished sawing and chiselling, sandpaper the resulting side surfaces by using a wood bar with sandpaper 80 to obtain the necessary dimensions and shape of the projections

To make the groove for the crossbar :

mark the groove
cut the upper layer of the plywood following the groove’s outline
drill a 10 mm hole at the end of the groove
saw the groove while making an allowance for sandpapering
chisel out the remaining material
sandpaper the groove to obtain the necessary dimensions and shape

Note : obviously, there are two side panels, each being a mirror of the other. The marking will be made on the exterior (and, therefore, visible) surfaces of each panel. Care should be taken to avoid chipping of the surface when sawing and chiselling.

After the panel has been made, it will be sandpapered with sandpaper 120, the edges and corners will be slightly chamfered.

Step 4: Seat

The seat is 300 mm wide and 260 mm deep; it has two grooves 50 x 12 mm to fix the seat on the side panels. The grooves will be made as follows :

mark the grooves
cut with a sharp knife the upper layer of the plywood
drill 10 mm holes at both ends of each future groove
chisel the grooves while leaving an allowance for sandpapering
sandpaper the grooves by using a 20 x 10 mm hardwood bar with sandpaper 80 to obtain the necessary dimensions and shape

After the seat has been made, it will be sandpapered with sandpaper 120, the edges will be slightly chamfered. The corners should be rounded (radius of curvature 2 … 3 mm) with sandpaper 80 and 120.

Step 5: Backrest

This part is similar to the seat, its dimensions are 300 x 260 mm; it has two grooves 50 x 12 mm to fix this part on the side panels. The grooves will be made as follows :

mark the grooves
cut with a sharp knife the upper layer of the plywood
drill 10 mm holes at both ends of each future groove
chisel the grooves while leaving an allowance for sandpapering
sandpaper the grooves by using a 20 x 10 mm hardwood bar with sandpaper 80 to obtain the necessary dimensions and shape

Step 6: Crossbar

This part connects the side panels to make the chair more rigid, it’s 300 mm long and 70 mm high; it has two grooves 35 x 12 mm to join this part with the side panels. The grooves in the crossbar will be made as follows :

mark the grooves
cut the upper layer of the plywood following the grooves’ outlines
drill 10 mm holes at the ends of the grooves
saw the grooves
chisel out the remaining material
sandpaper the grooves by using a 20 x 10 mm hardwood bar with sandpaper 80 to obtain the necessary dimensions and shape

After the crossbar has been made, it will be sandpapered with sandpaper 120, the edges will be slightly chamfered.

Step 7: Assembling the Chair

The parts of the chair will be joined with wood glue; I used one that dries quickly. I proceeded as follows :

apply a layer of glue on the grooves in the panels and the crossbar
insert the crossbar into the grooves into the side panels and place the subassembly on a plain smooth surface
assure that the crossbar is perpendicular to the side panels
apply a layer of glue on : a) the grooves of the backrest; b) the panels' projections for the backrest; c) the panels' side surfaces that will touch the backrest
install the backrest onto the side panels
apply a layer of glue on : a) the grooves of the seat; b) the panel's projections for the seat; c) the panel's side surfaces that will touch the seat
install the seat onto the side panels

Step 8: Writing Pad, Top

The writing pad’s top dimensions are 300 x 220 mm; it has two grooves 50 x 12 mm to fix the bracket. The grooves will be made as follows :

mark the grooves
cut the upper layer of the plywood following the grooves’ contours
drill 10 mm holes at both ends of each groove
chisel the grooves while leaving an allowance for sandpapering
sandpaper the grooves (sandpaper 80) to obtain the necessary dimensions and shape

After the top has been made, it will be sandpapered with sandpaper 120, the edges will be slightly chamfered. The corners should be rounded (radius of curvature 2 … 3 mm) with sandpaper 80 and 120.

Step 9: Writing Pad, Bracket

This piece is composed of four elements :

upper part
bottom part
reinforcement rib
side support

The support had to be made of two parts to assure the comfortable height of the writing pad. The drawings of these parts are shown in the pictures. There is a groove 35 x 12 mm in the bottom part’ it serves for fixing the bracket on the seat.

After the upper and bottom parts have been joined by using wood glue, two 10 mm holes will be drilled in the parts to insert hardwood studs for reinforcing the joint. The assembled bracket is shown in the picture.

The reinforcement rib adds rigidity to the top and is placed at 125 mm from the outer edge of the top.

The side support reduces the bracket’s bending. This part is manufactured of the material remaining after the side panels’ projections have been made.

Indeed, I did not waste small pieces of plywood, my point being to use only one sheet of plywood. Those pieces were 12 mm thick, about 10 … 11 mm wide, and had various lengths; I selected those that were 50 … 90 mm long and transformed them, by sandpapering, into small bars with regular cross section 12 x 10 mm. Then I used them as I needed; specifically for the latch and the side support.

For example, to make the side support I glued together six small bars and manufactured the part according to the drawing (see the picture).

After the parts have been made, they will be sandpapered with sandpaper 120, the edges will be slightly chamfered. The corners should be rounded (radius of curvature 2 … 3 mm) with sandpaper 80 and 120.

Step 10: Armrest

This part’s drawing is shown in the picture, it’s 200 mm long and 44 mm wide; there is a groove 50 x 12 mm in the armrest to fix it to the upper part of the bracket. The groove in the armrest will be made as follows :

mark the groove
cut the upper layer of the plywood following the groove’s contour
drill 10 mm holes at both ends of the groove
chisel the groove
sandpaper the groove to obtain the necessary dimensions and shape

After the armrest has been made, it will be sandpapered with sandpaper 120, the edges will be slightly chamfered. The corners should be rounded (radius of curvature 2 … 3 mm) with sandpaper 80 and 120.

Step 11: Assembling the Writing Pad

I proceeded as follows :

apply a layer of wood glue on : a) the grooves of the pad’s top; b) the two first projections of the assembled bracket; c) on the side surfaces of the bracket that touch the top
insert the bracket into the top and put this subassembly onto a plain smooth surface; assure that the bracket is perpendicular to the top
apply a layer of glue on the side surfaces of the reinforcement rib that will touch the subassembly and install the rib; assure that the rib is perpendicular to the subassembly
apply a layer of glue onto the side support and install this part
apply a layer of wood glue on : a) the groove of the armrest; b) the third projection of the bracket; c) the side surface of the bracket that will touch the armrest
install the armrest onto the bracket

Step 12: Latch

In fact, there are two features that serve to fix the writing pad to the chair :

the groove in the bottom part of the writing pad’s bracket. The seat has a cutout (see the picture) that allows the bracket to form an easily detachable joint with the seat.
the lateral latch fixed to the right side panel with glue and three screws for wood.

The latch is composed of a rectangular piece 75 x 45 mm and three small bars that I made of the material remaining after the projections have been cut out. The ‘Bracket’ section explains how to make these bars. The ready piece will be sandpapered, the edges slightly chamfered.

Step 13: Finishing and Painting

I looked for possible imperfections on the exterior (visible!) surfaces of the chair, found some, filled them with filler (a mix of fine sawdust and wood glue) and sandpapered the surfaces with sandpaper 120.

I painted the chair with ‘oriental green’ acrylic paint by using a small paint roller and a brush. Three layers of paint were applied.

Step 14: Manufacturing Options

It’s also possible to make only the chair; in this case you go through steps 1 to 7 and then finish and paint the ready piece of furniture. The image is for reference only; there will be neither the latch not the cutout in the seat, if the 'chair alone' option has been chosen.

As to the writing pad, its bracket could be fixed to the side panel with 2 or 3 bolts M6 with washers and nuts. However, two wrenches would be necessary to unbolt and detach the writing pad from the chair in this case. Those who envisage this writing pad to be permanently fixed to the chair might consider exactly this option.