Mr. Runner

Creating a four legged robot with a running bound gait.

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The aim of this project is to lower the barrier of entry into dynamic robotics. After seeing Boston Dynamic's Wildcat I became interested in working on something similar, but was disappointed with what the hobbiest scene had to offer. They all used static locomotion. I wanted it to feel alive!

I hope that if people can see that this style of robotics is reproducible with basic development skills, it will attract a wider range of people to legged robots than just those who want to see a vaguely spider looking device re-implement the same kinematic equations over and over again.

The approach is based on the work of Fumiya Iida and Rolf Pfiefer at the University of Zurich in the mid 2000's. Dr. Pfeifer is well known in the field of embodied cognitive science, and these experiments were an attempt to generate movement in quadruped robots based on those principles.

  • 1 × Tin
  • 1 × PLA
  • 8 × HS-422
  • 4 × HS-5685
  • 1 × Arduino Uno

View all 14 components

  • Completed PCB

    Alex Martin07/24/2017 at 01:26 0 comments

    This is an improved version of the board discussed in a previous log. The main difference is that this one works.

    Changes include the removal of QFN packages, better spacing, and proper trace routing.

    The primary area for improvement here is to integrate the bluetooth module into the main board.

  • QFNs may have been a bad idea...

    Alex Martin10/30/2016 at 01:14 2 comments

    I put the board together a couple of weeks ago, but have been unable to get it to work properly. I successfully installed the Arduino bootloader on the ATMega, but can't load sketches onto it. From what I can tell it's because the the reset pin is not being held at 5V (for reasons I don't understand). This is confusing as the master Arduino uses the reset pin of the slave Arduino to upload the bootloader.

    The FTDI chip also doesn't work. It's hard to debug as I didn't create any test points on the board. It doesn't show up in the /dev directory, and using the FTDI utility doesn't lead me anywhere.

    I'm going to leave this board as is for now and keep the failures in mind for the next revision. I will be using QFPs instead of QFNs in case bad solder connections were the cause of the failures (I have re-soldered both chips multiple times, each time inspecting with a microscope). I will also be adding test points to the FTDI chip to help with debugging.

    Below are pictures of the soldered board (yes, those are bodge wires). At least it was fun to put together!

  • It's all coming together...

    Alex Martin09/08/2016 at 01:52 1 comment

    Just submitted an order to @oshpark!

    This board is based off the incredible Botboarduino by Lynxmotion ( It has some features removed (speaker, some IO etc), and some features added. The new additions are:

    - Current sensing (ACS715)

    - Bluetooth (BlueSMIRF)

    - Juicier battery traces with ring terminal connectors

    The premise of the design was to keep the components as tight as possible (hence mostly surface mount), have the servo connectors / power connectors on the same side, and the USB connector opposite to the servos / power. This board will be mounted in the rear body of the robot (not much space!) so it needs to be concise and well organized.


    Board view:

    I got lucky and the design was sent off the fab immediately after it was submitted, so the boards should be here in around a week. Alright!

  • New updates coming soon!

    Alex Martin09/03/2016 at 17:41 2 comments

    PCB, design, videos, etc.

View all 4 project logs

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Arex try wrote 11/10/2023 at 17:43 point

This project holds the promise of a future where robots not only master dynamic locomotion but also excel in sports like tennis, mirroring human athleticism. The fusion of dynamic movement principles and sports showcases the versatility of legged robots, captivating a broad audience and pushing the boundaries of what's achievable in robotics. Exciting times ahead!

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LuckerDang wrote 01/05/2017 at 08:43 point

coo!! Can't wait to see your progress!

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Alex Anderson wrote 09/14/2016 at 19:28 point

Love the spring/servo combo for the movement system! Can't wait to see your progress!

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Dennis wrote 09/12/2016 at 23:52 point

Very cool! I love it!!!

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oshpark wrote 09/12/2016 at 23:08 point

Great project!  We look forward to future updates!

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deʃhipu wrote 12/19/2015 at 17:20 point

I liked it already when you posted this robot on letsmakerobots, and I have to say I still like it a lot! Amazing that it managed to pull off the "rabbit"-like gait with just those weak servos!

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Alex Martin wrote 12/19/2015 at 21:01 point

Thanks. It's a shame what happened to LMR! That place is a shadow of its former self.

For the bound gait, the robot has 5685s at the hips, not 422s. It is possible to use the 422s, but the resulting movement is more of a scuttle.

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