Video 1

Video 2

Video 3

Step 1: Prepare a uniform cylinder and mount it on the lathe

Step 2: Mark a centre line for the sphere and then mark out the radii on either side using the radius of the cylinder

Step 3: Turn down the parts of the cylinder beyond the marks

Step 4: Mark out mid-points on the ends and between the centre-line and the ends

Step 5: Turn down flat to these marks

Step 6: Start curving by eye

Step 7: Use a plastic cup to check curvature repeatedly

Step 8: When satisfied, part off sphere

Step 9: Mount sphere in specially made supporting chucks as shown

Step 10: Continue using the cup test for curvature

Step 11: Sand through all the grades

Step 12: Apply finish of choice

Billy de Klerk starting with a prepared cylinder	Marking out the sphere's radius and diameter (that of the cylinder)
Trim away ends	Start with a "square" cylinder
Mark half-way points	Trim flat
Both sides trimmed	Start rounding by eye
Cup test	Repeated many times
Part off sphere	Mount in prepared supporting chucks
Sand through all grits	Decorate and finish as desired
Andrew Stevens mounts a bowl blank	Shaping the base
Cutting a recess	Trimming the top face
Base of a different bowl	Top view of the bowl