Making a Period Chair

A
Period Chair



Figure 1 is taken from a Renaissance painting;
figure 2
shows a chair based on the same design. It is the only period design I
have so
far discovered which combines three desirable features: It is
reasonably easy
to build, it is very portable, and it provides back support.



My version differs from the picture in two major
and several
minor ways. The first major difference is that it is designed to be
easily
disassembled for transport. While the original was presumably glued,
mine is
held together by a rope, as shown in the figure. The second is that the
back
support on mine is substantially lower than in the figure. I built it
that way
because the support is on a vertical dowel, so if high forces me to sit
with my
back more nearly vertical than I like. Further experiments should test
my
conjecture that the lower support is more comfortable for me.



Materials
for the
chair



2 front legs, 2² hardwood dowels
18"
1
hardwood plank 8²x22²x1/4² (seat)

1 back leg, 2" hardwood dowel
28²

1
hardwood plank 3/4²x6²x2 (back)

3 lower horizontals, 3/4" hardwood dowels
16² 9' of rope + 1 random stick

3 upper horizontals, 7/8² hardwood
dowels 16"



Total Cost: Approximately $50



Figure 3 shows side views of one of the front
legs, the back
leg, and the back support (which attaches to the back leg). Figure 4 is
an end
view showing the placement of the holes into which the horizontal
dowels fit;
it is the same for all three legs and, unlike the other figures, is
full sized.
To get the placement and angle of the holes right, make two copies of
Figure 4.
Cut the circles out and glue them to the top and bottom ends of each of
the
legs, making sure their orientation is the same; use a flour and water
paste to
make later removal easier. Then draw a line connecting point a on the
top copy
with point a on the bottom and another connecting b with b. The center
points
of the holes at A1 and A2 will be on line aa, the center points of the
holes at
B1 and B2 on line bb. To get the angle of the hole correct, orient the
dowel so
line aa' (or bb', depending which hole you are drilling) is vertical,
than
drill straight down. The upper two inches of the back leg have a flat
surface
on their front where the back support is attached. The support is
slightly
convex in the horizontal direction and rounded at the front top edge,
as shown.




Figure
3
Figure
4



The seat fits into grooves in the upper
horizontals, shown
in Figure 5. The ends of the 7/8" dowels are reduced to 3/4" to fit
the corresponding holes (A1 or B1) in the legs. The tip of the support
is cut
at an angle to fit flush against the corresponding end of the other
support
going into the same leg. The lower horizontals have similarly angled
tips but
no groove. Their diameter is a little less (3/4" instead of 7/8")
since they don't have to be big enough to fit the seat into, so there
is no
need to reduce the ends to fit the holes (A2, B2).



Figure
5



The seat is two pieces of 1/4" hardwood plank
as shown in
Figure 6. It's shape is an equilateral triangle with circular arcs cut
out of
the tips. Each side of the triangle is 16 1/2", the radius of the arcs
is
1 1/4". The exact layout depends on the width of your plank; the figure
assumes 7". It may require some trial and error to get the dimensions
just
right--big enough to fit all the way into the grooves but not to keep
the
horizontals from fitting all the way into the holes in the legs.
Remember that
removing wood is easier than adding it.


Figure
6



Once all the pieces have been cut out and the back
support
glued to the front of the upper end of the back leg, the chair is ready
to be
assembled. Fit all of the horizontal supports into the corresponding
holes in
the chair legs, being sure to orient the angled ends so they fit
together. This
should also put the slots in the upper horizontals where they need to
be to
hold the seat. When the whole thing is fitted together, tie the rope
twice
around the three legs between the two sets of supports as shown in
Figure 2 and
tighten it with a stick. If your joints are tight enough, you may find
that the
chair will hold together without the rope.



Tools:
You will need
a saw to cut pieces to length and to cut the flat surface at the upper
end of
the back leg, where the back rest glues on. To drill the holes use a
drill
press, a portable electric drill, or a brace and bit. All holes are
3/4"
so that is the only size bit you need. You can put the groove in the
upper
horizontals with a bench saw or radial saw. It should be possible to do
it with
a hand saw and chisel, but a lot of work. If you want to try, I suggest
marking
two lines 1/4" apart for the edges of the groove and driving several
small
nails into the dowel along one of them to serve as guides for the saw.



A spokeshave and file can be used to reduce the
ends of the
upper horizontals enough to fit into the holes in the legs; if you
don't have a
spokeshave, use a plane or chisel. To shape the chair back I used a
chisel to
remove the superfluous wood then a belt sander to smooth it.
Alternatively, you
can start with a 1/4" thick piece, steam it and bend it. To do that,
you
get a pot with a lid, big enough to fit the wood piece in horizontally.
Put in
an inch or so of water and a bowl to rest the piece on. Bring the water
to a
boil, put the piece on the bowl above the water, cover it, steam for
ten or
fifteen minutes, then clamp the piece to a suitably curved surface
until it
dries. I have done only a little experimenting with this, so you may
want to
talk to someone with more experience steaming wood.



Variations:
The
dimensions are for a chair that fits me; you can experiment to get it
right for
you. For proportions closer to those of Figure 1, use a longer dowel
for the
back leg. If you never plan to disassemble the chair, use glue to hold
it
together instead of rope.



The picture below shows a variant on the
chair which has the advantage of being substantially easier to make.
The seat is leather instead of wood. That means you don't have to
groove or taper the upper horizontals--just use 3/4" dowels like the
lower horizontals. The seat is a piece of vegetable tanned leather, 8
ounce or heavier, that wraps around the upper horizontals; I laced the
edges to each other as shown in the second picture, which shows the
chair upside down.


One thing I did wrong in the chair shown was to cut the back support
with the grain running vertically--making a split in the short
dimension easy (discovered the hard way). It should run horizontally.