Train Music!!
This is probably my longest lasting MOC project to date. Back in 2001, I realised that the 6 speeds of the LEGO train controller driving a standard 9V motor produced the first 6 overtones, ie: the notes available to most valve-less brass instruments. I didn’t do anything more on it until yesterday, when for some obscure reason I decided to finish the project.
So here it is for your enjoyment (or otherwise).
August 10th, 2009 at 2:21 pm
That is beautiful. I hadn’t thought of trying an on/off switch for my own musical LEGO projects, but it will definitely be useful for testing ideas (now that I think of it, my NXT programs for this sort of thing just turn off the motor immediately before “playing” the next “note”).
Personally, I’ve been more into using the non-train 9V motors and using various RCX and NXT power settings to produce different tones. I haven’t done the proper research/tuning to figure out if I’m playing any real notes yet (planned to put that off for a bit to work on other projects). Is there documentation anywhere of what the power settings produced by a Speed Regulator are? Is there a fairly simple way to determine if we’re producing actual notes (or to tune the motors if we find out we’re not)?
Your mic placement gives this some nice volume, but I’ve actually found another cool way to make the fairly quiet motors audible over other noises – I have an electric guitar with a cheap pickup that I can crank 9V motors through. I can just adjust the amp to change the volume of the motors in relation to other instruments.
August 15th, 2009 at 7:23 pm
Hi Dan, thanks for your comments.
I don’t know of any documentation about this – I just happened to notice this by accident. But the notes are pretty close by my ear, I guess the circuit was designed to get the changes in speed as even as possible, and that just happened to produce this result. I have yet to investigate the circuit itself to see what is going on.
I imagine I could get better recording results by not attaching the mic to the motor – it picks up a lot of motor noise that doesn’t contribute to the tune. But I was lazy and didn’t want to waste too much time on it 🙂 You could probably change the range of notes available by adding resistance to the wheels – perhaps with 5 or 6 of these you could get the entire chromatic scale 🙂
September 29th, 2009 at 12:40 pm
Very, very nice work. And possibly the most unusual track on my .MP3 player (in between Cat Stevens and REM tracks in my alphabetical sort).