ha yes, i want to build kind of a bass robot.
the head pushes a small rubber wheel against the string, and if i can work it out, there will be a mechanic built in to lift the wheel off the string and /or a mute mechanic. If the lift/mute won't work, it'll be fine too. there is a magnetic hammer which slaps on a string, and of course it will not sound like a human played bass at all. the hammer does rhythmical stuff (it's quite fast), while the printer head pitches around based on a MaxMSP patch. At least that's the plan. Really looking forward to programming weird basslines.
for the printer motor; it's a standard DC and works fine with 9V input. the slide has a range of about 40 cm, sufficient for fret 1 through 12.
so i'll definitely need position sensing i guess... it doesn't have to be super-accurate (+-5mm should be okay enough). It also just needs to detect 12 'hot spots' on the fretboard, with the head being capable of moving from one spot to a specified other...
so yeah, the next important step is how to get/build a 12-step position sensing system which sends noob-friendly data to arduino...
i've also been looking for linear potentiometers... what's used in mixing desk sliders. But can't quite find anything appropriate (inexpensive) yet.
nice song btw!