Many visitors to the Mill are surprised to learn that some of
the gears transferring the power from the waterwheel to the millstones
are fitted with wooden teeth. Millers found that using wooden
and metal toothed gears together produced less noise when the
mill operated and reduced the wear on the metal toothed gears.
It also acted as an additional safety factor as the wooden teeth
will break under excessive force.
The teeth, or cogs, were usually made from apple, cherry or hornbeam
wood, cut to shape before being inserted into the cast iron gear
wheel frame. If a tooth became worn or broken,
it could be removed and replaced by a new one.
The top picture shows the stone nut, the last gear driving the
millstones, fitted with wooden teeth. The stone nut is keyed onto
the stone spindle but is able to move up and down. In the picture,
a block of wood is shown holding the stone nut up and out of gear,
away from the driving bevel gear. This prevents the stone spindle
and the runner millstone from rotating.