Scratchbot: A Robot DJ That Can Scratch And Cut Records

It’s becoming clear that automation is the future for many jobs and industries out there – but did you ever think it might come to the DJ turntablism world? DJTT member mushrooshi has shared exclusive details with us on project to build robots that can gate the crossfader and manipulate vinyl in time with the beat. See it in action and read our interview with the man behind the robot DJ revolution inside.

First, watch the current prototypes in action – they’re obviously early concepts still. Here’s the both parts of the robot working together to cut over a familiar theme song:

And a closer look at the crossfader cutting bot  – here’s a recent video of it in action:

We asked him to walk us through a few parts of his creation and the thinking behind it – read his responses below.

Hey Mushrooshi! What are you trying to build here, exactly? 

I’m creating a robotic system which is able to perform turntablist scratches with high precision, synchronized with Traktor. I’d like it to be able to perform in two modes: firstly as a reliable “Instant Gratification Scratching” system, where I hold buttons down to play pre-programmed scratch routines on the fly, and secondly as kind of the turntable equivalent of a “player piano”, where a music loop plays and the scratchbot selects random patterns to continuously play.

So what are the specifics of how each bot works? 

The robotic system’s mechanisms are currently comprised of two parts. The first part is a simple crank, powered by a single servo and attached to the mixer, which controls the crossfader. It’s currently on it’s third prototype, which has been 3D printed. It’s action is almost perfect right now and only needs a bit more calibration.

The second component is a swinging arm, powered by two servos, one servo which pivots directly over the turntable’s axis of rotation and controls the scratching sweeping motion, and the other servo of which controls if it is pushing down on the record. It is on it’s second prototype at the moment, and works okay with a small 7-in record. However, the scratchbot’s performance is poor with 12-in records, likely due to the increased surface area with the slipmat and the much heavier mass and inertia of a 12-in record. I’ll need to heavily redesign it for it’s third prototype, which unlike the first and the current prototypes, will be mostly 3D printed.

How did you get your parts/components? 

Most of the electronics were sourced off Amazon, including the Arduino Mega2560 and Sunfounder’s Project Starter Kit. Some of my servo motors and servo mounting hardware is from my local Hobby Town. Many of the “raw materials” for creating the prototypes I just had lying around in my room. Actually… I think some of the cardboard I used was from the Amazon box that shipped my Arduino, haha. I made a trip to Walmart hunting for some nice grippy material for the arm to press down on the record with and my haul included some stuff like shelf liner and a silicone potholder, but I found a heel cushion and a dashboard phone grip-mat worked the best.

As far as the 3D printed parts go for the later prototypes and very likely the finished robots, I actually have them printed out by my school, Texas A&M University. I was taking a Materials Science midterm early and after completing it, I had a discussion with my professor Tanil Ozkan and his student Yasushi Mizuno, who are setting up an Open 3D Printing Studio for students to use. They liked the idea and decided to help me out with my project by printing the parts for me; It’s fantastic being able to design a part and send it off in the evening and receive it right before my next class!

What about software? What’s behind the scenes here? 

The mechanisms are controlled by an Arduino Mega, which takes in MIDI control from Traktor (Via the loopmidi and Hairless MIDI utilities) in order to synchronize with the beat of the music (which is played in Traktor). I originally used an Arduino Uno R3, but I found it’s memory was likely too limited to store the amount of scratching routines and patterns I wanted to include.

The Arduino counts the MIDI clock’s ticks in order to time movements within a beat, and Traktor’s Beat-phase MIDI output controls when to iterate the beat counter and reset the tick counter to zero (indicating the start of a beat). I initially had problems with it either “slipping” or adding an additional beat randomly, but now it is able to keep time for over 5 hours (at which the test only failed because my laptop overheated, causing the CPU to throttle and Traktor to glitch).

What drove you to create this scratching robot in the first place? 

I’ve always been interested in robotics since I was a toddler, and DJing is only a more recent interest of mine, having started three years ago. I’m not sure how I came up with the idea to make a robot turntablist, but when I came up with it, I really wanted to do it. I did some searching and found a couple other attempts at creating a turntablist robot, but while they were both interesting attempts, both seemed to only manipulate the record without cutting with the crossfader and neither performed well enough for me to want to include in a real performance. I had lots of free time over the summer and I haven’t built a robot since high school, you could say I was… itching… to make this project a reality. I told my father about my idea (who’s been very supportive with all my past robotics endeavors) so he’s been helping me finance this project, which I’m very grateful for!

I’ve had a few people asking why I didn’t go with a purely software solution (such as emulating turntablist maneuvers via MIDI input), which indeed would be more reliable and easier to do; I just find the mechanical mechanisms very fun to design, and its extremely rewarding to not just hear a perfect output, but see the action behind it physically happening in front of me. That, and robots are just really cool!

We’ll continue checking in with Mushrooshi as his project develops. If you want to learn more about the specific components or read his build log, check out this link!

3d printingcrossfaderrecordsrobot djrobotsturntablism
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  • Dj Tools Scratch Records | Computer DJ Equipment

    […] Scratchbot: A Robot DJ That Can … – It’s becoming clear that automation is the future for many jobs and industries out there – but did you ever think it might come to the DJ turntablism world? […]

  • djtetsuo.

    How predictable.

  • 11Fletcher

    2017 The scratch machine can do almost every scratch technique
    2019 The scratch machine can reproduce a DJ Craze routine perfectly
    2021, Pioneer present the new CDJ8000, with the new fonction “Auto-scratch”.
    2025, A-Trak and Q-Bert declare “I use auto-scratch as it give me more time to do other thing”.
    2032, Sky-Net is the n°1 DJ on Top 100 DJ mag, headliner of all big festival and DMC champion solo and in team categorie.

    • Ambesa Tesfa Negus

      i laughed so hard, dang i wanted to copy and past this funniness!!!

    • dj arsenal

      And it became self

  • akswun

    this robot needs to #practiceyocuts

  • Chris Hanser

    R-2-DJ 😀

  • CUSP

    This is what I believe is the future of DJ Performance controllers. Purpose built (and modified) controllers for the individual to optimize for their playability.

    I’d host/go to DIY classes addressing this, because No One is doing this as (both an instruction and technique organization), now.

    3D Printing is good for this, but so is hacking the chips and controlling the software.

    Any thoughts?

  • calgarc

    I am tottally diggin the DDR controller on the side 🙂

    • ?MU?SH?OO?SHI™ ?????

      I have a metal pad I built, decided my softpad can still be useful as decoration 😛


    LOL I DJ with him at school… SHROO YOU MADE IT DUDE

    • ?MU?SH?OO?SHI™ ?????

      ayyyy #DJsOfAggieland

  • Chris Wunder

    Pretty cool, I can’t scratch myself let alone design a robot to do it for me so props lol.

  • Lun3r


    • CUSP

      There are no other boundaries to DJing other than the will to do so.

      • djtetsuo.

        Man. That was predictable.

        • Enoch Kim

          your legacy to the world, share it with ya kids 😉

          • ?MU?SH?OO?SHI™ ?????

            I was probably in this video, in the crowd somewhere.

    • Cedar Behnke


  • ?MU?SH?OO?SHI™ ?????

    It was a joy being interviewed by you Dan! I’ll keep DJTT up to date with the progress of my robot! Thanks again!