Mechanics of Bobblehead Dolls

Nowadays, custom bobbleheads are very popular. But do you know how these Bobbleheads work? Here in this article, you can get an idea about the working principle of this bobblehead in detail.

A bobblehead doll is an exaggerated version of person’s head that is tied to the body and a stand by a spring. A gentle tap on the overweight head allows it to bob. The head moves, vibrate and oscillates. The backward and forward motion isn’t going to last forever. The movements begin to fade with time, and the bobblehead eventually ceases bobbing and returns to its normal resting position.

Bobblehead dolls are working on principles of vibrational movement.

Why Vibration occur in bobblehead?

The bobblehead has a resting position. In a resting position, the bobblehead’s head is not vibrated. The resting condition is also known as the equilibrium position. When an entity is placed in a position of equilibrium, it is in its equilibrium position.

According to Newton’s Law, an entity in a state of equilibrium is experiencing a balance of all forces. All of the forces, such as gravity, spring, and so on, are balanced. The forces on a bobblehead are balanced when it is in the equilibrium state.

When bobblehead is applied by force on its head, its equilibrium state gets disturbed, and the bobblehead started vibrating. The bobblehead oscillates backwards and forwards, repeating the movement. Repetition of backwards and forwards motion is somewhat less intense than the one before it. Over time, the degree of its deviation from its equilibrium state decreases.

The movements eventually stop because the forced pulse that started the movement is a single occurrence of short-term, momentary force. 

Damping is said to occur in the bobblehead. Damping refers to a vibrating object’s ability to lose or dissipate energy over a period of time. Other structures absorb the kinetic energy of the bobbing head. Without a continued forced pulse, the bobblehead’s back and forth movement gradually stops because energy is dissipating into the other objects. To keep the back and forth movement running, an ongoing supply of energy will be needed.

An object can continue to move if the applied forces are equal, according to Newton’s law of inertia.

So, at some point in time, when the bobblehead is in an equilibrium state, the momentary balancing of force will not interrupt the motion.

The bobblehead continues to move. It shifts away from the equilibrium position to the reverse side of its motion. When the bobblehead moves away from its equilibrium state, a force that is capable of halting or stopping it occurs. A restoring force is a force that stops the bobblehead as it moves away from its equilibrium state.