Wait, THAT’S An Electric Guitar?

Mechatronic Guitar

What you’re looking at above is a six-stringed mechatronic slide guitar, where each string and associated servos is assigned its own MIDI channel.

It’s a project [Jim Murphy] has been working on for a while now, and technically, it’s the second iteration — he’s calling it the Swivel 2. The original Swivel was more of a proof of concept, using bulky stepper motors and solenoids — in this one he’s upgraded to hobby style servos, using four per string. One to change the pitch, one to clamp the pitch shifter, and two to pick and dampen the strings.

He’s designed the PCB control boards himself utilizing an Arduino bootloader-equipped ATMEGA328, which takes in the MIDI signal from a computer and moves the servos accordingly — to produce the audio signals he’s been using Ableton Live to write the patterns.

The entire setup was designed in 3D CAD and is designed to be completely modular. He’s even made the guitar pickups himself using 3D printed spools, and hand wrapping the coils with copper enamel wire. Lend an ear after the break to hear it in action.

He’s primarily hoping to use this to create new sound effects for his various projects — and if it looks a bit familiar, that’s because [Jim] worked on the original MechBass we covered a few years ago!

36 thoughts on “Wait, THAT’S An Electric Guitar?

  1. Same as always, wrong readers at HaD.

    The ones that got their thumb mounted in the middle of their hand but got a mouth that’s just way too big.

    If you read these hacks at breakfast, just go to sleep again.
    You just woke up on the wrong side.

    1. Signifying there are wrong readers at hackaday would mean there are correct readers as well. So who would be the correct readers at Hackaday? The poor beleaguered Hackaday staff. Now they have to be concerned if an article could move the wrong readers to comment in a manner, that annoys the correct readers. ;)

  2. Come on guys, it’s a work in progress. Give the maker a chance to program it to play something awesome. Programming it is probably very difficult. The simple sounds it does play actually sound very smooth and consistent, I’d bet it would hold a tune pretty well, once sufficiently configured.

  3. The mechanical part is very nicely done, but the fact that the creator is actually into these weird sounds and not music, just ruins the hole project in my opinion. One thing is for sure, I will ever never understand art.

  4. From the author: “I do think that Swivel 2 should be capable of the playback of existing songs, but I’m not particularly interested in using it for that”

    Anyway, clearly HaD readers have quite little taste, this sounds great. :3

  5. I cannot believe how negative some of the comments are here. Getting this to work at all is a major piece of work. Sure, it needs refinement. But so what. As an illustration of what can be done it’s quite impressive, and by virtue of having completely separate mechanics for each string it is fully polyphonic. I would like to see this again when the developer has taken it further and has it playing some music – I think the video is just sowing the testing of the various elements.

  6. Aside from the usual 20th century atonal muck, there will be poor tuning even if a familiar tune with harmony is played. It’s better suited for this atonal stuff.
    Volume in video borders on silent. Built in mics, arguh!

      1. I think there is a good reason frets are at fixed positions…it’s takes a highly trained ear to play a fretless instrument like a violin and the isn’t feedback built in to compensate. I think this approach works ok for atonal music. (Imagine Kabuki cowboy music.) But I think the servo slide doesn’t work for traditional music.

  7. “Wait, THAT’S an Electric Guitar?” No disrespect to the builder; no this is not an electric guitar. Not what most of us picture anyway. Sounds like theremin to me as it’s playing The Bass build shows as that Jim can build a unit that can play individual notes. Not saying this is a terrible project, but I don’t see it playing something I listen to on a 3+ hour drive.

    1. I’d say, stick with your coyotes. It’s not something the rest of the world wants.
      We have enough of animals anyways.

      Regarding the sound, If you cant see what he’s doing, the fine.

    1. There is also LEMUR’s Guitarbot out there too. https://www.youtube.com/watch?v=lBxBe2dDvG0

      I don’t think Jim had a hand in it but a number of the mechanics between it and mechabass seem similar.

      I’m getting a 404 from the HaD link, but I’m curious as to what Jim was going for with Swivel 2. Is it kinetic sculpture? Exploring different methods to fabricate a string instrument bot? Something mechanical to play something that sounds like traditional Japanese music (that is supposed to emulate nature)?
      It’s art so we aren’t supposed to have to “get it”, but I’m still curious as to if there was intent and what someone interested in pushing the machine might do.

  8. As an instrument playing something between a sitar and a slide guitar and a zither, I think it sounds really neat. I hear bits of Asian musical scales in there, and some atonal stuff that sounds rather cool. I won’t even say ‘it needs more work’ or anything like that; it sounds awesome as it is and if it’s what the creator wanted then I’d say they did something pretty cool. The means by which it plays, slides, and can even tap the string with the slide is amazing. I’d like to hear a tapped harmonic 12th or 7th or even a 5th, but that’s the next point.

    Calling it an electric guitar, though, makes me want to hear at least some C->Am->G chords, or a tapped solo or something. I don’t care if it’s a song I know, like others who want to see a robot commit copyright infringement, but I want to hear a guitar like sound out of an ‘electric guitar’. Now if that’s just the HaD writer and not the creator making that comparison, then that’s just bad editorializing.

    1. The thing is that the hammer mechanism repicates a slide guitarists fretting- or more to the point non-fretting, and as a result you can’t replicate hammer on’s/offs ect as you have nothing to hammer to. So its not really able to replicate that. I agree that it is not a guitar in the classical sense.

      Jim’s work is awesome, he was involved in producing mechbass and has been working on a self tuning algorithm which adjusts the arm positioning as the strings move out of tune for each string. He’s also talked with me about producing a markov-chain driven jamming algorithm, where the robot would follow along with a human playing with it. I want to see that stuff waaayyy more than having him go through the arduous process of tabulating a song for the robot.

  9. Whats wrong is the strumming.
    A guitar is strummed. Or its not a guitar?

    My idea is a bit better.
    Use servos to string the guitar and then something strumming it?

Leave a Reply

Please be kind and respectful to help make the comments section excellent. (Comment Policy)

This site uses Akismet to reduce spam. Learn how your comment data is processed.