How to make your own music rolls
Most people who have built a crank organ of their own have often two right hands. They know how to use tools and have sufficient technical skills to build such a great music box. A second skill which you should have as a crank organ builder is the making of the data medium for the music. Often this skill will be viewed negatively because this work takes a lot of time and one should have musical knowledge for making music rolls. Fortunately it is easier than it looks. Assuming that you have a computer (otherwise you could not read this page), you can use it as a very useful tool for this. As already described in the chapter "What is MIDI", we use midi files for making books or rolls. With the help of computer program Midiboek (Midibook) from Piet Paardekam (see links), a midi will be translated into a template for a book or roll, which will be printed by the printer. You can use the printed sheets, provided that the sheets are glued properly. For punching of the books/rolls you should take account of the physical specifications of the music instrument. For instance with books, you should have a distance between two following holes of at least 2 mm of one key, so that there is sufficient material for pushing down the key. The mimimal size of a hole should be at least the size of the key so that a tone can be played. With a paper roll between two following holes of the same position there should be at least 1,5 times the size of the hole so that the membrane is able to close. With long notes you can make a distance of 1,5 - 2 millimetre between the holes, so that the paper remains stable. Through this distance there will always flow air and the organ will play a constant tone. In the photo below you see a simple punch machine: a 3 mm pin is driven by a electromagnet.