Mcpixel53 / midi-to-simple-metal-gcode

Script to convert MIDI files to gcode. I added specific instructions for the Printrbot Simple Metal.

midi-to-simple-metal-gcode

Convert a MIDI music file to gcode instructions compatible with the Printrbot Simple Metal. The conversion code was obtained from where this repository was forked from. My version for the Ultimaker 2 can be found here.

The concept behind how a 3D printer can generate musical tunes is explained here. That author also uses a Printrbot Simple Metal as well but did not mention his instructions so I created a short tutorial below.

##Demo videos on Youtube

Playing the Singapore National Anthem.

Portal Still Alive.

Birthday Song

Fringe opening theme. The reference piano-video for this can be viewed here.

Rey's Theme (Star Wars). The reference piano-video for this can be viewed here.

The Gcode for these are placed inside gcode_files directory.

##How to convert a midi file for the Printrbot Simple Metal?

Not all midi files can be supported or be converted properly. If my understanding is correct, only 3 notes can be played concurrently at any one time as there are only 3 axes motors available. The code will randomly pick any three notes if there are too many concurrent note playbacks.

###1. Generate the Gcode file

git clone https://github.com/yeokm1/midi-to-simple-metal-gcode.git
cd midi-to-simple-metal-gcode
python mid2cnc.py -infile midi_files/national_anthem_singapore.mid -outfile gcode_files/singapore_national_anthem.gcode -machine custom -units metric -ppu 80 80 2020 -safemin 0 0 0 -safemax 120 120 120 -verbose

Replace the relevant paths with paths to your input and output file. I have set the bed size at a conservative 120mm x 120mm x 120mm although the Printrbot Simple Metal can go up to 150mm x 150mm x 150mm.
The "-verbose" argument is optional.

To know what each argument means, check out the original readme file.

###2. Make some modifications to the generated Gcode file

Replace these lines

( Input file was xxx.mid )
G21 (Metric FTW)
G90 (Absolute posiitioning)
G92 X0 Y0 Z0 (set origin to current position)
G0 X0 Y0 Z0 F2000.0 (Pointless move to origin to reset feed rate to a sane value)
G04 P0.0000

with

G0 X0 Y0 Z0 F2000.0
G92 X0 Y0 Z0

The generated Gcode file seems a little "screwed" at the start because they set the origin at the current position then attempt to move to it (current position) which results in no movement. I removed the other stuff as they have no impact on the musical output.

###3. "Print" the Gcode Send the Gcode file to your printer using your favourite 3D-printer control software. I happen to use Octoprint but others should work just as well.

##Dependencies

1. Python 2
2. Any 3D-Printer control software that allows you to send custom Gcode commands

##Motor Current notes The volume the printer produces correlates to the motor current setting. You might want to increase the motor current before playing music then reduce the current later once you decide to use the 3D-printer as it was meant to do.

Send the following Gcodes if you wish to change the motor current setting

#To view the current setting
M909
#To set all motors to 90% of max current.
M907 X90 Y90 Z90 E90 
#Save the current setting
M910

I normally set this after I have done playing

#To view the current setting
M909
#To set all motors to lower current levels to reduce noise
M907 X20 Y20 Z70 E30 
#Save the current setting
M910

##Resources

1. Singapore National Anthem Midi file
2. Imperial March on 3D Printer
3. Fringe Midi video
4. Portal 2 Still Alive Score
5. Happy Birthday Midi file
6. Original Rey's theme Midi source I modified the downloaded file to remove the second piano track to reduce the number of simultaneous notes so the printer can play them.