Music boxes have an undeniable charm. The make especially good gifts for children. There is something about the sound of a music box that speaks directly to the heart with quiet simplicity. To make your own music box, you need to know the notes of the song and how to build the drum of pins that plays the notes when it revolves. A "comb" of tuned teeth play the tune when they are struck by carefully placed pins on the rotating drum.
Write out the tune you want the music box to play. If you are not a musician, you will need to get someone to help you with this part. You should pick out the melody on the piano. You can harmonise some of the notes as long as this does not mean that too many notes are used. The set of notes is limited by how many notes are in the comb. A musician can chose much better notes to use for harmonising your tune. Write down the names of the notes.
Order the movement, the comb and a blank drum. You can get these in a music store or hobby shop and there are hundreds of on line and mail order companies that sell movements -- these places also sell custom combs and blank drums. The comb should be ordered that has the notes for your tune. Blank drums come with the wire that you will cut up to make the pins.
Select the box. This is one of the advantages of building your music box instead buying it. You should choose a box made of wood or some other material so it will be easy to mount the movement on the inside of the box. If you choose a movement that has a long winding stem, you will be drilling a hole in the box as well. You should do this step after you have assembled the mechanism, so you can make sure that the movement fits in the box and the activation lever can be activated by opening the lid.
Drive the pins -- short sections of wire -- through the drum leaving a long section inside the drum. The pins must be positioned to strike the right comb tooth at the right time. When all the pins are in place, pour enough glue into the centre of the drum to fill it up. You can position the pins in and out any time up to the time when the glue solidifies. If the activation lever is properly positioned it will not interfere with closing the lid, but the mechanism should stop when the lid is closed. The winding mechanism should be in a place where the movement is easy to wind.
If your tune has two identical notes in a row, duplicate that note on the comb. Hitting a tooth while it is still vibrating can produce unmusical results.
Ragged ends on the pins where they strike the comb can damage the teeth. File them smoothly rounded before you insert them in the drum.