"Way in which files can carve themselves"
The machine is constituted of a base on which
a cart runs, connected to an endless screw,
which is connected in turn via gears and
pinion to a transmission shaft. At one of the
extremities of the shaft, a wheel with four teeth
engages a pivot, which in turn is connected
to a hammer. There is also a sprocket
connected to the transmission shaft.
A weight connected to the sprocket (not part
of the reconstruction, but present in Leonardo’s
drawing), falls by gravity to unwrap a cord from
the sprocket, causing the transmission shaft
to turn. The rotation of the shaft actuates the
wheel with four teeth, lifting the hammer and
causing it to fall, like a cam wheel. The hammer
thus cuts the file. The shaft simultaneously
moves the pinion and the toothed wheel
connected to the endless screw, moving the
cart on which the file is positioned in a manner
synchronized with the hammer’s movement.
The model is based on the drawing:
- Codex Atlanticus f. 24 r. (1480)
Milano, Biblioteca Ambrosiana