Wheel
throwing is one general form of pottery, the first step being
the centering of the clay to the wheel.
Three main forces are applied to keep the clay in place and
directly in the center of the wheel. A force from the top and
side push the clay down and into the wheel,
and a normal force is present as well that pushes
against the weight of the clay. From there the clay is pulled
upwards with equal and opposite pressure from both sides
before continuing the centering process by repeating the
initial steps.