The Principle of Music Box

There are 3 main components in wind up music box which are Winding mechanism , drum, and comb.After you wind, the drum will begin to spin and the music will play. In this section , I will mention only the drum and the comb, the parts that make each music box gives different music. These two pieces must be paired together, unable to put the drum of one song on the comb of the other.

Drum is a cylindrical steel with small protruding pins that produce the sound of the comb. The pin layout is placed in 18 rows corresponding to each tooth of the comb. The position of the pin determines when the comb will be stripped.
Credit Photo by https://www.youtube.com/watch?v=COty6_oDEkk
The position of the pin is determined from the computer. For example ,the layout of the ‘Senario’ song below, the pin is placed in 18 rows, each row hits only one corresponding tooth on the comb. Each tooth will give a different note (as in the leftmost column in the figure below). The number of rows must be 18, cannot be more or less. The process of creating a drum is very important and is the hardest part in making a music box. Each company has a different technique to create a drum. In general, a flat steel sheet is stamped with a mold. This will form a button protruding from a flat sheet called pin.Then the steel sheet will be rolled into a cylindrical shape. This method allows the drum to be produced very quickly and accurately. But the disadvantage is that the cost of the mold for one specific song can be costly. So it is more suitable for mass production. In order to create a music box for one specific song, we’ve been developing our drum manufacturing method for 3 years to create a drum without molding but still deliver the same accuracy of the pins in order to build a music box with flawless sound. Comb is a 1mm thick steel plate with 18 teeth ,each representing a note.
E3 F3 G3 G3 A3 B3 C4 E4 E4 F4 G4 A4 B4 B4 B4 C5 C5 C5

For instance, in ‘Senorita’ music box, 18 teeth of comb will be corresponding to these 18  notes respectively.

As a pin on a rotating drum hits each tooth , the tooth vibrates at specific frequency and gives a sound of the note. A longer tooth will yield a lower tone note. A Set of 18 notes is different  in each music box varied by music composition.