Convert a MIDI file to a record compatible with vintage (1970's) Fisher Price music box record players
Forked from Tycho's code at https://www.youmagine.com/designs/fisher-price-record
- wslib Quark
First, create or modify a MIDI file to play on the music box. Note that not all notes are not available. The notes you can use are: D#4, G#4, A#4, C5, D#5, F5, G#5, A#5, C6, C#6, D#6, F6, G6, G#6, A#6
The RPM of the disk varies depending on how tightly the spring is wound. A range of 34-40 seconds per revolution is normal. The SuperCollider script will scale your durations to fit in a single disk revolution.
The SuperCollider script will check your file to see if it uses the allowed notes and if not, will find a transposition if one exists.
First, check the transposition of your file:
f = FisherPriceRecords.openMIDI("~/foo.mid".standardizePath, "My Title");
If no transposition can be found, it will generate a warning and some lists of outside notes in the transpositions that were the closest fit.
Evaluate the result to see if it sounds ok:
f.p.play(\foo)
Write the scad file:
f.realise(1);
f.write("~/foo.scad".standardizePath);
The argument to realise is the number of times the midi file should
repeat on the disk. For very short files, you may want to increase the number.
This will scale the durations to so that every note fits in for every repetition.
Be sure fpRecordModule.scad is copied to be in the same directory as the scad file that you just generated.
Open your scad file in OpenSCAD and see if it looks ok. The file is human readable and you can make changes in it and fpRecordModule directly. You may wish to adjust the pin size and the groove width based on your printer specifications.
Press F6 to render it. Save it as an STL file. Rendering may take up to half an hour, so be patient.
Follow the manufacturer's instructions if your printer for how to use the STL file.