Carving The Sunburst
Like the fan, the sunburst consists of flutes, or peaks and valleys, or entirely of reeds.
The difference is that the sunburst is round or elliptical. The design can be incised into
the surface of the material or carved separately and let into a recess. To draw the circular
version, the circle is simply divided into an equal number of degrees; the widths of the
divisions of the perimeter (their chords) are equal as well. As with fans, it is difficult to
maintain the regularity of the elements as they diminish in width, so a central disk is
commonly used.
The ellipse is a little tricky because it is made up of two different arcs, which vary
depending upon the measurements of the major (longer) and minor (shorter) axes. One
method of drawing an ellipse when one knows the minor axis dimension is to use two
equilateral triangles (Fig 4.24a). Draw a straight line to represent the minor axis (the
vertical line in Fig 4.24a). Set your compass to this known dimension and, placing the
fixed leg on the line at A, draw a semicircle. Replace the fixed leg at the point where this
arc intersects the vertical line (point B), and again draw a semicircle, creating the vesica
piscis shape ADBC. Connect the four points ABCD to create two equilateral triangles, with
a common base on the minor axis. Bisect the altitudes of these two triangles to give the
points E and F. Use these two points as centers for the ends of the ellipse, adjusting the
compass until the arc is tangential to the larger arcs of the vesica piscis. (These end arcs
do not extend to the apexes of the triangles.)
Fig 4.24 Drawing the ellipse:
(a) the use of equilateral
triangles when the required
width is known
(b) The use of three circles
when the required length is
known
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Another method can be used when the desired
length of the major axis is known (Fig 4.24b).
Draw a straight line and mark on it the overall
length CD. Bisect this line and raise a
perpendicular as before, then bisect the two
segments so as to divide the overall length of
the major axis into four parts. At the three
internal points draw three overlapping circles:
the circumference of the middle circle cuts the
perpendicular at A and B, and passes through
the centers of the outer two circles; the outer
circles pass through the end points of the axis.
Fig 4.25 A small sunburst being carved
With center A, draw a large arc which meets the
in a routed recess. The center disk is
two outer circles at a tangent; repeat on the
being rounded over
other side of the figure, with center B. The
straight line drawn from A, through the center of
the outer circle, indicates where the circle and
the large arc merge.
One may have to suit the shape of the ellipse to
the available space. This is easily done by simply
changing the relationship of major to minor axis.
Retaining the length of the minor axis, the
ellipse can be made rounder by placing the
centers for the end arcs (points E and F) closer
to the intersection of the axes. Of course, the
closer they are to the intersection, the closer to
a circle the figure becomes. On the other hand,
as one moves the centers towards the apex of
the vesica piscis, the smaller the arcs (circles),
and the more pointed the figure becomes. The
Fig 4.26 The parting tool being used to
same applies when the length of the major axis
define the valleys between the reeds
is known: as the centers of the end arcs move
of a double sunburst
toward the axis intersection they become larger
(the radius becoming longer) and overlap. As the
centers move outward and become smaller, the
ellipse becomes narrower. Adjustments will have
to be made to the centers on the minor axis to
complete the figure.
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To mark out the flutes or reeds, it is not sufficient simply to pick a measurement and
step off the increments around the perimeter, or to give each division the same number
of degrees. This will look uneven, because the ends of the flute or reed are cut off
nearly perpendicularly at the axes, but obliquely between the axes. Also, the flutes or
reeds near the major axis will appear narrower than those near the minor axis (in spite
of the fact that the center disk is also an ellipse). Personal preference may require that
the major and minor axes be the centerline of reeds or flutes (as opposed to valleys,
which would be an easier layout). Instead of bogging down in mathematical
calculations, lightly sketching the increments of one quadrant will help you to determine
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how many increments fit well into the space. Some adjustment should be made so that
all elements appear to be the same width at the perimeter. Sometimes, of course, the
increments are so small that these issues are hardly troubling.
When transferring the design to the blank, I usually draw the ellipse directly onto the
material. It is hard to trace an ellipse through carbon paper accurately. Plastic
templates for this purpose can be purchased, but the largest are only 3 4in (75
100mm) in length.
The small sunburst being carved in Fig 4.25 illustrates the method of using a routed
recess to secure the blank. It also shows how the surface is sloped in toward the center
disk, the same as for a fan. For larger applied sunbursts, the waste from bandsawing
the blank can be used to hold the work. This piece can be snugged up to the blank and
nailed to a scrap backing board in order to hold the blank while carving. The holding
pieces may need to be made thinner than the blank in order to give access to the edges
of the carving.
Fig 4.27 Detail of double sunburst
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Fig 4.28 The double sunburst in position on the central frieze block of a mantel. Two vertically
oriented sunburst designs appear on the pilasters
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Fig 4.29 A variation in which the reed ends
are sloped to create the feel of a scalloped
edge; carved and let into a recess
Fig 4.30 A further variation, again set into a
recess, in which the flute ends are concave
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