Pattern making using the traditional sand-casting method
requires that patterns of the final shape be created. These
patterns are often constructed using wood, allowing for the
shrinkage of the metal from the liquid-poured state to the
cooled-solid state. A pattern can be composed of the final shape
pattern and potentially numerous cores, conducive to
passageways, cavities, or even full-hollow sections as found in
pipe. The pattern becomes the positive, and the core becomes the
negative, restricting the flow of liquid into a specific area.
To construct a cylindrical core, a core box must be created. It
becomes the mold used to construct the core. There are two
accepted methods for using a plane-type device to construct a
channel of semicircular cross section, creating a form for
making a round core. The first uses a V-shaped base to ride on
the sides of a roughed-out base that replicates one-half of a
cylinder. This type of plane is worked through the arc after the
final width of the semicylinder is calculate