Vibratory tumblers have an action that is similar to filing. An eccentric, rotating weight shakes the tub in a circular path, during which the entire load is lifted up at an angle and then dropped. As the load is falling (but not actually airborne) the tub returns to an upward position, applying an upward and angular force that causes a shearing action where the parts and media rub against each other. Vibratory finishing systems tend to produce a smooth finish because the media essentially
laps the parts. Since the load is moving as a unit, fragile parts are safe in the vibrator. There is no tearing action or unequal forces that tend to bend and distort parts. The larger the parts or media are, the faster the cutting action. show that the primary mechanism of material removal in vibratory finishing is erosion caused by the relatively normal impacts of particles on parts. These impacts occur at the same frequency as the vibration, and at impact velocities of less than 1 m/s. ==Media==