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Building a simple walking robot is really easy. Don't let the number of steps fool you into believing otherwise. This robot is basically made with a handful of household items and some simple electronics that you can easily pick up at Radioshack. In fact, this robot is entirely zip tied together, which makes building it and modding it extremely easy. If at any point you are unhappy with how its built, cut the zip ties away and zip tie it together differently.

The "brains" of this robot are also easily modifiable since it is based on an Arduino development board. Programming it and changing the code is extremely straight-forward. Even people with no programming experience can usually get up to speed pretty quickly and start coding their own robotic routines.

For me, this robot was mainly an experiment to see what would happen if I built a full-on robot that was like one of the many Simple Bots that I have built. It was interesting to see how much more robust one of these creatures become when you give it some computer logic.

Step 1: Go Get Stuff

You will need:

(x4) Rubber spatulas
(x2) 6" turnbuckles
(x1) 2" x 48" aluminum ruler
(x1) Ballpoint pen
(x1) 4-40 x 1/4" nut and bolt
(x1) Arduino Uno REV 3 (Radioshack #276-128)
(x2) Parallax 4-6VDC Standard Servo (Radioshack #273-441)
(x2) 3x1 male header pins (strips of 40 available in Radioshack #277-077)
(x1) Parallax Ping Sensor (Radioshack #276-136)
(x1) Heavy-Duty 9V Snap Connectors (Radioshack #270-324)
(x1) 9-Volt Battery Holder (Radioshack #270-326)
(x1) Size M Coaxial DC Power Plug (Radioshack #274-1569)
(x1) Multipurpose PC Board with 417 Holes (Radioshack #276-150)
(x1) 90-Ft. UL-Recognized Hookup Wire (Radioshack #278-1221)
(x1) EnercellĀ® Alkaline 9 Volt Battery (Radioshack #25-853)
(x1) 5-1/2" Zip Ties (Radioshack #278-1631)

Step 2: Saw

Get a 2" wide aluminum ruler.

Cut a 10" section off one end using a hacksaw.

Step 3: Bend

Clamp the cut section of ruler in a bench vise such that 5" are sticking out.

Bend the aluminum slightly (to about 30 degrees) using a rubber mallet or hammer.

If you don't have a bench vise, hang the ruler halfway off the edge of your workbench, place a block of wood atop the ruler and clamp it firmly in place. You have now made an impromptu bending rig.

Simply hammer down on the ruler until it bends down over the edge of the workbench.

Step 4: Take Apart

Take your turnbuckles and remove all of the eyelets.

Set them aside for some other project.

Step 5: Drill

Widen the second hole from center with a 1/8" drill bit on each arm of the servo horn.

Repeat this for the second servo.

Step 6: Mark and Drill

Place the turnbuckle on edge. Measure 3" across one of the turnbuckles. Make a mark at this point. Repeat on the second turnbuckle.

Place the servo horn at the 3" center point on the turnbuckle.

Position the horn such that it is making a "V" perpendicular to the length of the turnbuckle. This should, by default, position two more "V" shapes pointing to each side of the turnbuckle. Make marks in the valley of each of these "V" shapes.

Finally, drill these two marks with a 1/8" drill bit.

Repeat on the second turnbuckle.

Step 7: Mark

One inch from the edge of each of the far sides of the ruler, make a centered mark.

Step 8: Drill

Drill the two marks that were just made with 3/4" spade bits.

Step 9: Remove

Remove the servo horn from the servo by unscrewing the set screw.

Step 10: Mark Again

Center the servo's shaft in one of the 3/4" holes. Use the servo's mounting holes to make 4 marks on the ruler.

Rotate the servo 180 degrees and repeat on the opposite side.

Step 11: Drill Again

Drill each of the mounting marks that you have just made with an 1/8" drill bit.

Step 12: Zip Tie

Zip tie the servos to the ruler using the mounting holes you just drilled.

Trim away the excess zip tie tails.

Step 13: Reattach the Horn

Turn the servo's motor shaft entirely to the right or left.

Put the first servo horn back on such that all of the "V" shapes are parallel to each of the edges.

Fasten it in place with the mounting screw.

Repeat for the second servo motor.

Step 14: Mark and Drill a Bit More

Between one of the far edges of the ruler and the servo, place the PCB and make marks on the ruler through each of its mounting holes.

On the other side of the same servo, place the Arduino board and make marks in each of its mounting hole. Try to fit the whole thing to one side of the ruler's bend.

On the opposite side of the ruler's bend, place the battery mount and make a mark.

Drill all of the marks that you have just made with a 1/8" drill bit.

Step 15: Insert

Insert two zip ties into each of the holes drilled in the turnbuckles from the inside out.

Step 16: Attach

Place a turnbuckle centered atop a servo horn, and perpendicular to the ruler. Zip tie the turnbuckle firmly in place, and then trim away any excess zip ties.

Repeat this process for the second turnbuckle.

Step 17: Mounting Holes

Position the handle of the spatula about halfway up the turnbuckle such turnbuckle intersect perpendicularly. Next, rotate the spatula slightly outward (about 10 to 25 degrees).

Make multiple marks on the spatula's handle on all sides of the turnbuckle to indicate drill holes for zip tying it to the turnbuckle.

Drill the marks that you have just made with a 1/8" drill bit.

Flip the spatula upside down, and place the other spatula on top of it right-side-up. Align them so they are of matching height.

Use the first set of drill holes as guides to drill another set of holes in the other spatula. This should end up as a mirror image of the first (i.e. inverted, but otherwise identical).

Step 18: Front Legs

Using the holes you have just drilled, zip tie the spatulas to the turnbuckle closest to the holes that were drilled to mount the PCB.

For the best results, make sure they roughly mirror each other in position and height.

These two spatulas will serve as the front legs.

Step 19: Hind Legs

Repeat the process for the front legs to make rear legs.

Note that the rear legs of this bot were slightly shorter than the front legs. However, this is not a hard rule. Experiment and see what works for you.

Step 20: Spacers

Take apart a ball point pen.

Cut the pen's tube into 1/4" sections using a razor blade.

These will be used as spacers for mounting components

Step 21: Trim

Using a paper cutter or pair of scissors, trim the prototyping board down to about 1".

Step 22: 9V Adapter

Screw apart the M-type plug and slide the casing onto the 9V connector wires, such that you will be able to screw it back together later (after it is soldered).

Solder the red wire to the central terminal and the black wire to the plug's outer terminal.

Screw back on the plug's cover.

Step 23: Sensor Board

Place the ground lead of the Ping sensor into one of the long conductive rails that travels the length of the board, and place the power lead in the other. The signal lead should be in one of the smaller conductive rails that spans 3 holes.

Solder the Ping sensor in place at a slight angle such that if you hold the board parallel to the ground, it would appear to be rotated about 45 degrees clockwise. This should counter-balance the fact that the PCB will get mounted to the board at about a 45 degree angle.

One the opposite side of the PCB that the Ping was soldered to, nstall two 3-pin male headers such that each one has a pin that is soldered to the ground rail, and a pin the is soldered to the power rail.

Step 24: Wires

Solder a 6" red wire to the power rail.

Solder a 6" black wire to the ground rail.

Solder a 6" green wire to the terminal that the Ping's signal pin is connected to.

Solder a 6" green wire to each of the remaining header pins that are not connected to a power or ground connection. These two wires will correspond to the signal pins for each of the servos.

Step 25: Program

The code below includes the necessary bare bones minimum to make the robot walk forward and back away from something that gets too close.

This code could definitely be more robust, but I will leave it up to you to expand upon it.

Step 26: Sensor

Place a spacer between each of the PCB mounting holes and the PCB.

Zip tie it firmly in place.

If the sensor is not level to the ground, gently bend its pins until it is.

Step 27: Arduino

Place a spacer between the Arduino and each of its mounting holes on the ruler.

Zip tie it firmly in place.

Step 28: Attach

Attach the 9V battery holder to its mounting hole using the a 4-40 nut and bolt.

Step 29: Plug

Plug the servo female socket into the male header pins on the PCB, making certain that black is lined up with ground, red with power, and white with the green signal wire.

Step 30: Wire It Up

Plug the red wire from the PCB into the Arduino 5V socket.

Plug the black wire from the PCB into the Arduino Ground socket.

Plug the green wire from the Ping sensor into the socket for digital pin 7.

Plug the green wire from the front servo into the socket for digital pin 9.

Plug the green wire from the rear servo into the socket for digital pin 10.

Step 31: Power

Connect the battery to Arduino, secure it in the battery holder, and it is good to go.
<p>Hi! I'm wondering where you found those spatulas. Thanks!</p>
<p>Very nice done project,its wonderfull to enjoy this shared build thank you;</p>
<p>that is fantastic.....so simple and really cute...all it needs is a pink afro wig on its head...I really enjoyed reading this instructable...very well put together. .thank you.</p>
randofo, <br> <br>Thanks for the clear instructions to this amazing robot. It's the first I've ever tried to build. One question: I have a SainSmart HC-SR04 ping sensor that came with my Arduino. It's got 4 pins instead of the 3 on yours. They are marked 'vcc', 'echo', 'trig' and 'GND'. I'm assuming the 'vcc' is power and 'echo' is the signal. I've no idea what the 'trig' does. Any ideas if this sensor will work for the walker bot?
echo/trig are done by a single pin on my sensor. If you look at the code you will see the pin is toggled between an input and output. To make it work with your sensor, instead of changing the role of the pin, simply assign the roles to two seperate pins.
Thanks very much for your reply; very helpful! This will provide a good opportunity to learn how the code really works. I'm working now on the physical connections of pins and wires. Cheers.
<p>Did you get this to work? </p>
<p>My solder job wont work and i cant figure out why. please help!</p>
I think I found the answer the connecting the echo/trip pins to a single input on the Arduino here: https://code.google.com/p/arduino-new-ping/wiki/NewPing_Single_Pin_Sketch <br>As soon as I get my breadboard I'll give it a go with your sketch, and change your pingPin assignment to = 12. See what happens!
If the echo/trig are connected on the busboard, can they share the white wire from the servos? If not, any suggestions on how I might connect them to the servos separately?
<p>Randy, I built this - second Arduino project. Great instructions! Only thing I am struggling with is limiting the movement of the feet/rotation of the servos. The legs rotate until they stop against the robot body every time. Any advice on starting servo position and amount of travel?</p>
Cute!
really love how simple it is
<p>nice.and smart</p>
<p>For some reason the robot walks fine going backwards but not forward. Any suggestions on how to fix this problem? Thanks!</p>
<p>Great job! Now RadioShack is using your idea (Don't worry, they gave you you full credit) on their D.I.T idea brochures!</p>
<p>nice robot. Its somewhat more than a simple robot. good work, keep it up.</p>
cooooooooooooool.
I'm very new to electronics and especially arduino, and i'm having trouble finding '3x1 male header pins' in the UK. <br>Are they known as something else? Can someone point me in the right direction please? <br>I apologise if this is a really n00b question, just bear with me i'm learning hah.
They are usually sold in long strips and then broken into small bits.<br /> <br /> <a href="https://www.adafruit.com/products/392">https://www.adafruit.com/products/392</a>
Sorry to be a pain but is this the same thing? <br> <br>http://www.maplin.co.uk/0.1inch-series-straight-plug-pcb-header-1487 <br> <br>if not, why? <br> <br>Thanks
No. That type has that plastic side wall. That might interfere with the servos being plugged in... or it might not... hard to say. <br /> <br />I'd try to find one without the side wall.
So I got an Arduino and I want to build a walker like this but with one servo instead of two. (That's all I have. :I) I was also going to use two antennae instead of a ping sensor. What do you think would be the best way to go about building it with one servo. (It would have a tail that drags.) I have built one with the servo mounted in the front but it tipped crazily from side to side while moving forward. <br>Any ideas?
Randy, you're world famous!<br> <br> <a href="http://www.nopuedocreer.com/quelohayaninventado/21543/el-simpatico-robot-con-patas-de-espatula/" rel="nofollow">http://www.nopuedocreer.com/quelohayaninventado/21543/el-simpatico-robot-con-patas-de-espatula/</a><br> <br>
that he is
vc pode me ajudar com meu projeto? <br>
I am so excited by this, I have been meaning to play with Arduino for ages. It will be my first robot! Parts are on order!
OMG... it's the legendary Spatula Foot!!! ;-D<br><br>Excellent work, Randofo!!!
'spatula bot'
Haha, cool little walker. Well done!
My son will love this. He loves Robots and would be so happy to create one. I have no experience at all - so this is perfect. Thanks!
You should check out <a href="https://www.instructables.com/id/Simple-Bots/">Simple Bots</a>. They are about as easy to make as this one and don't require any programming, so are a little easier to get started with.<br /> <br /> If he ends up making something, please do post a picture.
Thank you SO much! I will check it out now. :) I will definitely post a picture once it's done..this sounds like a good project to do this weekend...my son is 7 but really smart so whatever I don't understand, he'll figure it out!
If I squint my eyes at this then I can imagine these things strolling down the street - like a non-threatening version of the &quot;War of the Worlds&quot; with their cute pink feet.
Maybe in the Spatula Bot movie; right, Randy? <br><br>Nice job!
liked your smile at 0:52... :D <br> <br>-Antzy
And very professional video too. <br>
You have my vote<br>
MARVELOUS Randy!<br><br>Can you make it to walk faster? I think it might be a good joke, many people would be scared to see it come unexpectedly.
Yes. It can go faster. At some point I just set it to that speed for testing, and never changed it. I should reprogram it to go faster.
Please, do it and post a video! With your girlfriend, mom or aunt being surprised by it...
Great use of common items. Sometime i try to over think a project and it gets to complicated. Thats why the zip ties ect are such a great idea. I see an industrial version used in the baking industries for robotic bowl scrapers. Joking of course.
Impressive Engineering use of of non-robotic components.<br> <br> LIKE <strong>:&not;|)</strong>&nbsp;&nbsp;&nbsp;&nbsp; A
You should ask scooch to add some ribbons on the feet paddles. They look like a ballerina-bot. Does it do a pirouette? Dancing with the robots?
Not yet. Working on version 2.

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Bio: My name is Randy and I founded the Instructables Design Studio. I'm also the author of the books 'Simple Bots,' and '62 Projects to ... More »
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