My latest piece is a droney violin prototype. Made from a violin body, piano tuning pegs, a motor from a RC Helicopter and my old favorite washing line for strings.
I’m going to think about adding some frets and seeing if i can play it like an automatic hurdy-gurdy of sorts.
Vulpestruments 
Did you ever come around to adding frets?
I'm very curious to know the details of how you built this/which parts you used. I have an old cheap violin laying around and would really like to build one!
I haven't got around to adding frets yet! Other projects and commissions got in the way.
The parts were all salvaged from bits being thrown away at work, so the neck is from the special stick used to keep piano lids open, the bridge and other bits were made from scrap wood, there's a tiny motor in it too.
One thing with this is that the tension in the wire is a bit more than I think the violin was designed for, so the neck did bend a bit under tension.
This one is a droning/=-fretted instrument that I think worked quite well: http://www.vulpestruments.com/2012/05/droneitar.html
Interesting! I'll keep that in mind, thanks!