Aluminalis: Our 16-legged Walking Creature

Arduino CNC & Machining Robotics
Aluminalis: Our 16-legged Walking Creature
Aluminalis-Building
“Let’s build something creepy, Dad…”

Let’s Build Something Creepy

That’s how it began. My teenage daughters and I had just completed our new workshop, including some exciting new tools in our machine shop area, so we were on the prowl for our next big project. My daughters enjoy building robots of all kinds, but they especially love robots that are biologically inspired. So we decided to construct a creepy crawly creature that would utilize our machining skills to the fullest. We had no idea how challenging a project we had taken on!

We love the artist Theo Jansen and his strandbeests, so we decided to use a Jansen-inspired linkage design. Theo powers his mammoth PVC kinetic sculptures with the power of beach winds in the Netherlands, but we’re not in to sand and surf here in the mountains of North Carolina. We like gears and motors, so we went with a more steampunk feel.

After months of design, machining, experimentation, and assembly, we finally completed our Arduino-based 16-legged walking creature.

We put together a short video that shows her in action.

Theo gives his strandbeests scientific names with a genus of Anamaris. So we named our creature Anamaris Aluminalis because she’s made almost entirely out of 6061 aluminum.

Building the Walking Mechanism

Aluminalis has two sides. Each side is powered by a single gearmotor. The motor drives a set of gears that turn a crankshaft. The crankshaft consists of 49 discrete components. It was the most challenging part of the project, and it’s the key to the robot’s functionality. After some experimentation (and failures), we decided to use a square shaft to rotate four sets of leg linkages 90-degrees out of phase. We constructed the crankshaft out of eight CNC-machined crank arms, square high-strength copper shafting, round aluminum shafting, and 6-32 set screws.

OLYMPUS DIGITAL CAMERA
The crankshaft is key to the robot’s functionality.

Each set of linkages provides two legs that move in a walking motion. The square crankshaft (which rotates smoothly inside a set of ball bearings in the connecting segments) assures that the leg pairs stay separated but synchronized with each other so that at least one pair of legs is on the ground at all times.

Aluminalis-one-leg-pair
Jansen-style linkage with one pair of legs, one motor and gears, and a portion of the crank shaft.

There are four pairs of legs on each side of the robot connected by five aluminum segments and two long steel 1/8” shafts that hold everything together. Although the crankshaft and linkages that create the walking motion are complicated, the robot actually uses  a simple two channel motor controller and standard differential steering.

Aluminalis-One-Side
One side of the assembled robot showing four pair of legs and the linkages that are operated by the crankshaft.

The Electronics

The creature’s central thorax encloses her internal electronics, which includes an Arduino Nano, a Sabertooth Motor Controller, an Xbee Radio, external antenna, three LEDs, two Maxbotix ultrasonic sensors, a 7.4V 1250Mah LIPO battery, a piezo sound buzzer, and the main power switch.

Aluminalis-Electronics
Aluminalis’ insides showing her electronics.

Completion

The completed Aluminalis robot consists of about 850 machined and electronic components. The girls and I have been having a lot of fun playing with her and programming her.

Be sure to check out our blog to see more of Aluminalis.

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Beautiful in form and function.

Behavior

Aluminalis operates by remote control and/or in various autonomous modes, but we have noticed that her favorite spot is to hide beneath the cabinets in our workshop and then pounce on any smaller robots that make the deadly mistake of going by her lair.

OLYMPUS DIGITAL CAMERA
I’m not creepy at all. Really.

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This week marks the official launch of Make: Volume 39 — Robotics, which drops on newsstands the 27th. Be sure to grab a copy at a retailer near you, or subscribe online right now and never miss another issue.

We are celebrating with five days of robot-related articles, pictures, videos, reviews and projects. Tune into this space for Robot Week!

Our next theme week will be wearable electronics. Send us your tips or contributions before it gets here by dropping a line to editor@makezine.com.

 

19 thoughts on “Aluminalis: Our 16-legged Walking Creature

  1. Aluminalis: Our 16-legged Walking Creature | Salute says:

    […] Read more on MAKE […]

  2. Aluminalis article in MAKE Magazine « Beatty Robotics says:
  3. Bratan says:

    This is amazing! I have a question, why 16 legs? Can lesser number be used?

  4. Robert Beatty says:

    Bratan: Thank you! :) We wanted to go for the super-wide creepiness of 16, but you could definitely use 12 instead of 16. You just need to keep the leg pairs 120 degrees out of phase instead of ninety degrees out of phase.

    1. IpseCogita says:

      Was about to post essentially the same question. Nice robot.

  5. Aluminalis: Our 16-legged Walking Creature | Arduino collector blog says:

    […] Read more on MAKE […]

  6. Happy Tinfoil Cat says:

    It’s so cute! The video was nicely taken as well, with the lighting and the slider use.

  7. Robot Week Wrap-Up | MAKE says:

    […] Aluminalis: Our 16-Legged Walking Robot […]

  8. Robert Beatty says:

    TinfoilCat: Thank you. We appreciate it. We had fun making the video. For the slider shot, we built a motorized metal track for the camera to move on. That was a project all on itself, but now we have it for future shots.

  9. Camille and Genevieve Beatty: Teen and Tween and Already Accomplished Engineers | MAKE says:

    […] designed a Mars rover for the New York Hall of Science (NYSCI), and built a creepy-but-cool 16-legged walking robot. They’ve also designed robots for other museums and for themselves, built their own quad […]

  10. Discovering the Future with Low-Tech Supplies, a Review of Robotics by Kathy Ceceri | MAKE says:

    […] A.I., and numerous sensors available for on- and off-world applications. There are drawbots and walker ‘bots and even open-source robot offerings these days. Humans build robots for competitions and even […]

  11. Holiday Gift Guide for Tinkerers, Makers, and DIYers - Spokane County Library District says:

    […] beginners, and MAKE magazine regularly features some of the awesome things people are making, like this mesmerizing sixteen-legged robot, this open-source knitting machine, or these ballet slippers that render a dancer’s movements as […]

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As the founder and CEO of Plex Systems, Robert Beatty was one of the pioneers of the cloud services industry. He retired in 2006 to spend more time with his family and pursue his writing career. Today, he and his daughters build robots for their own fun and learning, and sometimes for museums. His first novel for young adults will be published by Disney-Hyperion in 2015.

View more articles by Robert Beatty
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