POLYRO (oPen SOurce FriendLY RObot)




Introduction: POLYRO (oPen SOurce FriendLY RObot)

This is an instructable on building a relatively low-cost wheeled robot platform for developing ROS applications. Think of ROS as an operating system for your robot (providing hardware abstraction, device drivers, libraries, visualizers, message-passing, package management, and more). THIS ROBOT IS NOT PLUG AND PLAY. ROS runs on Ubuntu, so you should feel comfortable working with Linux.

POLYRO, short for oPen sOurce friendLY RObot (yes I know, it's a bit of a stretch), is based off of the TurtleBot platform (from the good folks at Willow Garage) and inspired a great deal by Pi Robot (developed by Patrick Goebel). I designed this platform with Human-Robot Interaction (HRI) in mind. This is the first of many future iterations, so check for updates to the design. Please keep an open mind when following this tutorial. Many of the parts and tools can be substituted (or purchased for less) and there are many improvements to be made. As always, when working with power tools use the proper safety gear.

Step 1: Suggested Tools and Parts

  • Dremel*
  • Clamps
  • Removable Double-Sided Tape
  • Screw Driver Set
  • Needle-nose Pliers
  • Jig Saw (or maybe a Scroll Saw)
  • Saw Horses
  • Drill Press (Dremel Work Station)
  • Dremel Sanding/Grinding Kit
  • Soldering Iron
  • Sponge
  • Glue Gun
  • Large Format Printer (Kinkos)
  • Metal Ruler
  • Safety Goggles
  • Work Gloves
  • Dust Mask

Parts List

10.1-Inch Netbook
1 x $150 to $300

iRobot Create® Programmable Robot
Item Number: 4400
1 x $129.99 – www.irobot.com

Kinect for Xbox 360 with AC Adapter (Refurbished)
1 x $119.99 – www.Gamestop.com

Wide 2" Gusseted Plastic Angle Bracket (pack of 8)
4 x $1.59 - www.budgetrobotics.com

Risers, Set of Four 1" Steel)
4 x $1.69 - www.budgetrobotics.com

Gusseted Plastic Angle Bracket (pack of 8)
2 x $1.59 – www.budgetrobotics.com

White Expanded PVC 24" x 48" .120" Thick
Item #: 42485
1 x $12.85 – www.usplastic.com

White Expanded PVC 24" x 48" .240" Thick
Item #: 42488
1 x $27.86 – www.usplastic.com

Gray Expanded PVC 24" x 48" .120" Thick
Item #: 42501
1 x $16.50 – www.usplastic.com

250 Grams of ShapeLock
1 x $14.95 – www.shapelock.com

Bioloid Frame F3
Item #: M-300-B-BPF-F3
3 x $1.49 – www.trossenrobotics.com

Bioloid Frame F2
Item #: M-300-B-BPF-F2
1 x $1.49 – www.trossenrobotics.com

Dynamixel AX-12A Robot Actuator
Item #: FRS-B-AX-12A
11 x $44.90 – www.trossenrobotics.com

Robotis USB2Dynamixel Adapter
Item #: FRS-B-USB2D
1 x $49.90 – www.trossenrobotics.com

SMPS2Dynamixel Adapter
1 x $4.90 – www.trossenrobotics.com

Bioloid Bolt & Nut Set
Item #: M-300-B-BPF-BNS
1 x $23.40 – www.trossenrobotics.com

Bioloid 6-Port Cable Hub
Item #: FRS-B-6-PT-C-H
1 x $4.95 – www.trossenrobotics.com

3 pin Bioloid Servo/Sensor Cables (Set of 25)
Item #: FRS-B-CBL
1 x $34.90 – www.trossenrobotics.com

Logitech QuickCam E 3560 Refurbished
SKU: 130419
2 x $10.99 – www.microcenter.com

On Stage Foam Ball-Type Mic Windscreen (Blue)
2 x $4.95 – www.amazon.com

Wall Mount Bracket Dock Stand for Kinect
SKU: 267-363-001
1 x $9.99 – www.meritline.com

USB to PDA 9-pin Serial Adapter
SKU: 173369
1 x $29.99 – www.mircocenter.com

6” Novak Heat Shrink Tubing Assortment 24 pcs
1 x $3.74 – www.amazon.com

High-Tech Rosin Core Silver-Bearing Solder (1.5 Oz.)
Model: 64-013
1 x $5.79 – www.radioshack.com

25-Position Male Solder D-Sub Connector
Model: 276-1547
1 x $2.29 – www.radioshack.com

Schmartboard 201-0001-01
1 x $5.00 – www.schmartboard.com

USB 2.0 4 Port Hub – (Black)
SKU 502880
2 x $2.99 – www.microcenter.com

0.33μF and 0.1μF capacitors
2 x each

Voltage regulator 12V 1A
2 x each

22 AWG wire (red and black)

Machine Round Head w/Nut (4-40 x 3/8)

USB extension cable

Velcro tape (optional)

White model paint (optional)

Step 2: Preparations

Before you get started, I would suggest first reading through the entire tutorial. I built this robot using the resources that were readily available to me, but you may have different tools and equipment at your disposal. I used a jig saw for fabricating the majority of the parts; however, a cnc router would offer far better results. The eye lids were also hand made using Shapelock, a drimel, and a toy ball (from a Robosapien V2); again, better equipment such as a 3D printer would have offered better results.

The parts which are cut from the sheets of expanded PVC were first designed using Adobe Illustrator. I have provided the original files for both reference and editing. Those files were then printed to scale using a wide format b/w printer at Kinkos. Using tons of removable double-sided tape, I outlined the parts on the reverse side of each printed sheet of paper. The sheets of paper were then placed carefully on the sheets of expanded PVC.

Parts 1 PDF: White Expanded PVC 24" x 48" .240" Thick

Parts 2 PDF: White Expanded PVC 24" x 48" .120" Thick

Parts 3 PDF: Gray Expanded PVC 24" x 48" .120" Thick

Step 3: Cutting the PVC Sheets

*It is important to take the proper safety precautions when working with power tools. Please use the proper protective gear when cutting, sanding, drilling, etc.

Once you have mounted the sheets of paper to the sheets of PVC, clamp them to the saw horses. When starting a cut or cutting tight corners, I find that drilling holes first (using the dremel) is very helpful for producing cleaner results. Always cut the small shapes from inside of the larger ones before cutting the larger shapes.

After cutting all of the parts from the PVC sheets, use different sanding drum bits from the Dremel Sanding/Grinding Kit to refine each part. Clamping a metal ruler to a part helps immensely when shaping straight edges using the Dremel. Next drill holes using the Dremel Work Station, guided by the paper still taped to each PVC part. Finally, peel off the paper and voilà, you have finished parts.

Step 4: Fabricating the Eyelids

The eyelids were made using Shapelock, a tough, machinable, paintable plastic, which becomes pliable at 150F. It is suggested not to overheat Shapelock. Just boil water and pour it into a bowl that you do not intend to use again (for eating from). Next, place the Shapelock material into the water until it becomes transparent. After that, remove the Shapelock using tongs and squeeze the excess water. Before it cools off, mold the Shapelock to the shape of the eyelids. This can be done with a plastic ball (slightly larger than the webcam). I drew the shape of the eyelids on the plastic ball with permanent maker as a guide. Once you have two eyelids which you are comfortable with, sand them with the dremel.

You will also need an additional T-shaped part to connect and move the eyelids. This too can be fabricated using Shapelock. Please refer to the pictures below for dimensions. Sand the part down using the Dremel and make sure that it can rotate freely through the holes in the bridge of the nose.

Step 5: Assembly

*Note: Before assembling be sure to test and position each servo to 0 using RoboPlus Manager. It is also important to assign separate ID's to each servo.

I will continue to update this tutorial over time while I work on Polyro v2.

The original design files have been attached in both Illustrator and PDF formats; this is to help guide your assembly and allows for you to make changes to the original design. I also tried to group specific parts together within the three PDF's (arm parts, head parts, etc.). It should be easy to assemble POLYRO using the Illustrator file, PDF's and photos of the finished robot.

The Gusseted Plastic Angle Brackets were chosen to simply the assembly process and add stability to the robot. When assembling, start from the bottom and work your way up. Drill a hole in the *Polyro Base (see image above) large enough for the iRobot Serial Cable to pass through before attaching it to the Create. Mount the Kinect Bracket Dock Stand before adding the metal risers to the Kinect Mount Base (see image above).


I used #4 x 5/8" metal screws for the arms and shoulder brackets (see image above). Bolts from the Bioloid Bolt & Nut Set also work great when assembling the arm.


*When preparing to mount the USB cameras to the AX-12 servos, you can disgard the clamp-like base, but be sure keep the black circular part that snaps into the bottom of the camera. This small circular piece will be screwed onto the modified Bioloid Servo Bracket (shaped into a circle using the Dremel). Once that is done, it is easy to snap the USB cameras onto the servos.

If there are any other parts in the assembly process that are not clear, just let me know and I will update this tutorial.

Step 6: Wiring

Powering the Kinect and AX-12 servos was fairly easy using the Create's Cargo Bay Connector. I simply attached two 12V regulators from the 10/21 and 11/25 pins (see page 10 of the iRobot Create Owner's Guide). The process of creating the 12V regulator can be found here:


Instead of using the Create serial cable or RooStick (as in the tutorial), I simply ran it straight from the Cargo Bay Connector. For powering the AX-12 Servos, I simply repeated the process, only splicing a Dynamixel 3-pin cable (please reference the photo below). Remember to cover the solder joints with heat shrink to avoid any shorting. Once this is complete, the Kinect and AX-12 servos will be powered from the Create battery. I would like to eventually charge the netbook from the iRobot Create Home Base  (like in this project ) or replace the netbook with something that can be run from the Create's battery (such as the Roboard).

Step 7: Software

Now comes the fun part, making your robot do stuff. This can be accomplished using ROS. One of the great things about ROS is it's flexibility. You can use and add to software designed for other robotic platforms, such as (TurtleBot, Pi Robot or Trike). TurtleBot, developed by Willow Garage is similar to POLYRO, minus the AX-12 servos and USB cameras. I suggest installing and running TurtleBot on this platform initially.

Video of TurtleBot can be seen here:

You can always add drivers for the servos and webcams later (once you begin developing your own nodes, packages, repositories, etc.).

Instead of installing TurtleBot, you can also search the available software on ROS.org and install each driver manually.

Step 8: Afterthoughts

I am working on a website and will eventually create a dedicate ROS page for the POLYRO project. If anyone is interested in working with me to develop applications for POLYRO, please feel free to contact me. In the second prototype, I will add additional degrees of freedom to the neck, arms and head. I will also try to make improvements to the original design. I look forward to seeing your modifications to POLYRO and I appreciate any input that you may have.

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    8 years ago on Introduction

    Great, thanks a lot! As if my project list wasn't long enough!! Seriously though, nice instructable! it's got some great ideas that I can pull from for my builds!


    I have recently completely redesigned a server robot i have been working on for some time (and will be writing up an instructable soon) and i would like to add xbox kinect to the irobot create. Would it be effective to add a pan and tilt type feature to the kinect or does it work better when it is stationary?


    Reply 9 years ago on Introduction

    I have not experimented with using a pan/tilt feature with the Kinect... yet. Polyro v2 has the Kinect mounted directly on top of it's head, so I will be testing soon. Check out Healthcare Robotics Lab approach:


    They used pan/tilt with the kinect on a couple of platforms. They also have their STL files available for download. I hope this helps.


    9 years ago on Introduction

    can polyro be used without the iRobot Create? I am wanting to make a similar robot but funds are limited and can not get one right now. We just lost my father and my mom would really love something like polyro to keep her company. Can give him a full AI if just a computer can be used.


    Reply 9 years ago on Introduction

    I am very sorry to hear that you lost your father. You have my deepest condolences. Polyro can certainly be used without the icreate. I am actually preparing to release a new upgrade from Polyro named Maki. This new robot will be totally 3D printable (excluding electronics, servos, etc.). It will be available on Kickstarter in the next week or so and the STL files will be available to contributors sometime in February. Message me you email address and I will be sure to send you a copy of the STL files next month. Take care


    10 years ago on Introduction

    How much did this end up costing you in the end?


    Reply 10 years ago on Introduction

    Roughly $1200, but it depends on what supplies you already have at your disposal.


    10 years ago on Introduction

    which webcams did u use to make the eyes
    and can i use roller sakets and make 2 curcit for the legs to move and which software should i download for my ideas to work help ubuddha


    10 years ago on Introduction

    we are trying to modify and make polyros (our version) i want 2 know about the movement and the charge of the mainframe


    10 years ago on Introduction

    dear u buddha
    i wanted to know where have u got the parts from and r they avalable online?
    hope for a quick response


    Reply 10 years ago on Introduction

    I have attached to this instructable the parts in PDF format for download. You can have the parts cut from sheets of expanded pvc with a CNC router or by hand with a jig saw and Dremel. The servos, dynamixel2usb, etc. can be purchased from Trossen Robotics or directly from Robotis. On a side note, I am working on 2 new open source robots which use standard servos and more user friendly software. I will release them later this year.


    10 years ago on Introduction

    dear ubuddha
    i wanted to know where can we get the required material and is it AVALABLE ONLINE


    Reply 11 years ago on Introduction

    The final cost for me was roughly $1300, but that could vary depending on what parts and tools you already have available (i.e., netbook, Dremel, etc.).


    Reply 11 years ago on Introduction

    The main expense that is killing me are the 11 actuators. phew!

    Do you think that this would work with a Roomba 530 instead of a create?

    And just go through the serial RIO


    Reply 11 years ago on Introduction

    Robot servos can be quite costly. In the future, I would like to explore a couple of alternate configurations (perhaps building POLYRO without the arms or substituting POLYRO's head with the Kinect)...

    ROS does support the Roomba 500 series:


    It would just be a matter of mounting...


    Reply 10 years ago on Introduction


    Thanks for the reply. I have since burnt up my roomba 530. I got a factory cable from irobot. It was made overseas. It had a big glob of solder on the inside shorting out the whole thing. I plugged it in to the 530 and it fried the motherboard of the 530. IT would cost me around a hundred dollars that I do not have to get it going again. :-(

    But, I have worked with other units and I am having fun. But, none looks as cool as your design.

    When you get some code, please post it.


    Reply 11 years ago on Introduction

    Thanks! Now another question: Is this robot able to do stuff like navigate through homes and interact with people? And how would you program it? Is that what the netbook is for, your programming console?


    Reply 11 years ago on Introduction

    Yes and yes. POLYRO uses ROS (Robot Operating System) which runs on the netbook. I always suggest first going through the basic tutorial which can be found here:
    Next when you are ready to make your robot "do stuff," you can try more advanced tutorials.
    Head tracking:
    Face tracking: