



In the instructions I'll walk you through how to:
  1. Modify the servos for continuous rotation
  2. Fit the track hubs on to the servos
  3. Make a custom battery pack
  4. Wire it with a few connections
  5. Assemble it
  6. Program it
  7. Customize

For the basic platform the following supplies are needed:
an Arduino nano
a small rechargeable battery
a pair of 9 g servos, modified for continuous rotation
part of a Tamiya track set
a 40 pin dip socket
a rubber eraser
some zip ties

Step 1: Construction: Modify the servos


  1. Remove the tiny screws and open the case

Step 2: Construction: Drill the hubs to size


Step 3: Construction: Make the battery pack

Any battery which fits on the chassis would work



The photos explain how I did this better than words can:
  2. Remove the shrink wrap
  5. Fold it in to shape
  6. Wrap it up in electrical tape
  7. Picture how it fits on the chassis

Step 4: Construction: Connect the wires to the socket

A socket is used to mount the Arduino Nano to the robot, besides making the Arduino removable so that it can be used for other projects, this simplifies attachment to the rest of the machine. Alternatively you could buy a small breadboard for $4 (as shown in the second picture below from sparkfun.com) and zip tie it to the top in a similar way for more modular design.



Step 5: Construction: Assemble the microbot




Step 6: Programming: Basic operation


Really, the basic code to build on is just this:



Servo leftDrive;  // create servo object to control a servo
Servo rightDrive; //another servo object for the left side

void setup()

void loop()
  //here put commands which drive the servos 
  //use the commands
  //rightDrive.write(any number 0-180);
  //leftDrive.write(any number 0 to 180);
  //which way is forward depends on your servos


So that gives you an idea how simple this can be.



Servo leftDrive;  // create servo object to control a servo
Servo rightDrive; //another servo object for the left side


void setup()

void loop()

//example routine, drives in a square


//opposite for your build

//turns right about 90 degrees
void turnRight()

//turns left about 90 degrees
void turnLeft()

//drives straight for 1 second
void driveForward()

//drives straight backward for 1 second
void driveBackward()



Step 7: Customize it




Here is an example which would fit right on:


Jameco 1.3 inch gripper

Radio Control





Detect movement (PIR)



Ultrasonic Range finding



There is also support for the PING range finder: http://arduino.cc/en/Tutorial/Ping



Future Steps



<br> Really, really neat!<br> It's hard to make a narrow robot when you're using continuous rotation servos because of the gearbox height, but you've overcome this with the tracks and the asymmetric mounting method.<br> Just to clarify, you've drilled a hole for the idler pinion in the servo bottom cover in line with the spindle?&nbsp; Must have been pretty tight in there - the boards in those 9g servos don't leave a lot of room.
This is awesome mini tank. What I would do when making this is add a claw and a lazer
it's awesome. but can I use a keyboard to provide the input to this minute Robo?
<p>I'm thinking of things I could add on to this. So I'd like some feedback from anyone interested. What kind of wireless would you most like to see? WiFi, Bluetooth, simple radio such as a OOK transmitter?</p><p>Any other uodates? Maybe a different miniature electro-mechanical part like a claw/grabber.</p><p>Also, changes to make it more usable. Let me know, no matter how simple or complex.</p><p>Thanks</p>
<p>thank you is very good too</p>
<p>I'm looking at some potential li-ion batteries and was wondering what you would recommend? I found a 250mAh 3.7V battery on eBay, do you think that would cause any issues with a 5V arduino nano?</p>
<p>I considered this too. I've found that in my case at least the Nano will not turn on at 3.7V. However, the chip onboard is an ATmega328, rated for 1.8 to 5.5V. The reason it won't run at 3.7V is the 5V regulator on the board. Bypass that and it will run down to 1.8V, though depending on your servos you will need more than that, 3.7V seems to be enough for the 9g servos I've been using.</p>
How much does this cost in total
<p>If you get cheapo parts on ebay*. about $30</p><p> *I haven't used these particular parts, they may be crappy</p><p>$5.50 for the micro servos [<a href="http://www.ebay.com/itm/2x-SG90-Micro-9g-Servo-For-RC-Helicopter-Hitec-JR-Futaba-Align-Trex-US-Sel-/191402239783?pt=Radio_Control_Parts_Accessories&hash=item2c90766727" rel="nofollow">for example</a> ]</p><p>$5 for the nano [<a href="http://www.ebay.com/itm/Arduino-compatible-Nano-V3-0-ATmega328-Mini-USB-Microcontroller-Board-Cable-HIYP-/221608533427?pt=LH_DefaultDomain_0&hash=item3398e5ddb3" rel="nofollow">ebay</a>]</p><p>$10 for the tracks [<a href="http://www.ebay.com/itm/NEW-Tamiya-Track-Wheel-Set-70100-NIB-/390914477064?pt=Educational_Toys_US&hash=item5b04518c08" rel="nofollow">ebay</a>] though I would reccomend making your own, since you don't need the whole kit, and I just had the small wheels left over. For example you could use plastic bottle caps and silicon bracelets.</p><p>I salvaged the battery, but if you can't find an old cell phone battery something like this would do: $2 [<a rel="nofollow">USB li-po charger</a>] $6 [<a rel="nofollow">tiny single cell li-po battery</a>] convieniently, this is already the right voltage to run the arduino nano. One could easily add jumpers to make it charge while hooked up to program.</p>
<p>Hey, I've been meaning to purchase some threads for my RC projects and on your link for the tracks[ebay] they cost 7.59+12.75 shipping when on ebay app or pc, but i check your link when on mobile it's 7.59+2 dollar shipping? I'm confused. Did you buy them with shipping for 10 dollar? are they based near you,thus shipping was lower?</p>
<p>Hi, this is great project. I'm little confused about communication between the Arduino Nano and the Andorid app.</p>
<p>I have followed the instructions on how to make the servo have continuous rotation, but as it doesn't have the potentiometer connected, the servo doesn't realize that he finished turning and it never stops. Please, someone help.</p>
<p>That is what is supposed to happen. The servo is supposed to turn continuously (around and around without a limit) rather than just moving to a position. To allow this, rather than the signal giving you a particular position, it will give you a particular speed.</p><p>So to stop, you must send the signal for zero, which is usually a 1.5 ms pulse, on a normal servo this would be the middle position. Likewise 2 ms is full forward speed for as long as the signal is applied, where on a normal servo it is full forward position for as long as the signal is applied. Likewise 1 ms will run full reverse, while on a normal signal it would hold in the full reverse position.</p><p>note: some servos vary in exactly where their forward, 0 and reverse limits are. IE they may stop at 1.3 or 1.7 ms pulse.</p>
Thanks, I discovered the numbers for my servo. <br>Full forward:180<br>Full backward:0<br>Stop:85<br>For a strange reason, the stop is not in the middle.
<p>Hello! I saw it and I wanted to help. I believe it is a problem caused from the potentiometer inside of the micro servo. But, when you &quot;hack&quot; the servo for full rotation, potentiometer will not matter and it should work just fine. For hacking the video, you can find bunch of videos online.</p>
<p>Can you do it with the raspberry pi?</p>
It could certainly handle the calculations, being way more powerful by orders of magnitude than a nano. It might be a bit big.
<p>Do you think you can try to do it?</p>
<p>I might, but I don't actually have a pi to work with. I mostly use microcontrollers on my own boards rather than dev boards. I do have a few, some arduinos, a cypress pioneer kit, some beagle bones, but no pi.</p>
This looks awesome! I plan on making a pair of these rc controlled with laser and light meter modules on these and having them be mini battle tanks :)
how i can make a nano tank controlled by bluetooth with this? (sorry for my bad english)
No worries, your English is good. This is easily acomplished. For an adapter use an hc-06 module, you can get them for $7 or so on evay and they use rs 232 serial, which the nano supports. I refer you to this other instructable : http://m.instructables.com/id/Bluetooth-Controlled-Arduino-RC-Car/all/<br>You would have to replace the motor commands with the kind i used with the servo library. Also there are free apps with blutooth rc controllers which may work better for you since that instructable doesnt detail the app very well.
<p>Great project!</p><p>Having a hard time finding genuine Arduino Nano's and I'm Leary about 'compatibles'.</p><p>Can I use an Arduino Micro instead?</p>
Yes, that certainly would work. In fact any chip or board that can generate a PWM signal at 500 Hz can do it, though some require an external programmer. It looks like the Micro does have a USB connection of it's own so you should be all set.<br><br>On another note, I haven't had much trouble with 3rd party arduino based boards, but the genuine ones are of better quality, and it is good to support the people who create the IP.
<p>I didn't see this comment. It got buried. According to the arduino Nano datasheet it prefers 7 to 12 volts. So if you can't find the type of battery I used a 9V should do it, or an 11.1 lithium battery (which would need a special charger), or any other battery pack that will get you a voltage in that range.</p>
<p>That's it's top speed in the video. Maybe 1/2 m/s, I would guess. That depends on the servos and drive wheels you use.</p>
<p>That is one sleek-lookin' robot! Great job.</p>
is there a way to do this with arduino uno<br>
<p>The robot could certainly carry one, and the servo library works on uno as well (it was actually on uno first) so if you wire the power and servo signals to an uno there is no reason it shouldn't work.</p>
<p>Great! Congratulations!</p>
<p>use an H-bridge motor driver<br>it ll wrk fine</p>
<p>That approach would work, but you could only turn in one direction. If that is ok then yes. For a simpler approach, check out the L293D, it contains 2 H-bridges and can drive two motors both directions . It can be gotten for 1.25+$5 S&amp;H at sites such as this (<a rel="nofollow">https://www.taydaelectronics.com/catalogsearch/res...</a></p><p>And if you search on google for Arduino L293 you will find a wide array of diagrams on how to connect it, and code examples of how to use it, because it is a very common chip.</p><p>It handles about 0.6A per channel, and comes in a DIP package. If you need more there are several other &quot;Push pull&quot; or two channel H bridge chips, including the L298n.</p><p>If there is any confusion about how to use it just ask. Like I said theres a ton of example code and diagrams out there.</p>
Excellent, thank you!
Couldn't you just use a regular motor instead of a servo. It might bring the price down. And the code<br>Would just change a little bit
<p>May i ask you where i can find these wheels and belts ? :)</p>
<p>These are from a set, <a href="https://www.google.com/shopping/product/11557235404563389032?q=tamiya+tank+tread+and+wheel+set&rlz=1C1CHFX_enUS564US564&espv=210&es_sm=122&sqi=2&bav=on.2,or.r_cp.r_qf.&bvm=bv.62578216,d.aWM,pv.xjs.s.en_US.Qb9R7Hul644.O&biw=1024&bih=600&tch=1&ech=1&psi=xu8cU_yECoqtqgH1gIHADg.1394405326276.3&sa=X&ei=2e8cU8HzGMe0qgHI_ICYCw&ved=0CFsQ8wIwAA" rel="nofollow"><strong>Tamiya</strong> TAMX8001 70100 <strong>Track</strong> &amp; <strong>Wheel Set</strong></a>. Though you will get a lot of extra parts that way. I actually had these left over after I made a bigger set from that kit.</p>
<p>Oh thank you :)</p>
hey <br>i also wannna do a similar stuff. i want to design a robot for surveillance where the robot will be fully autonomous and it wil move for point A to point B autonomously. <br>i want u to help me in designing the autonomous motion planning system to go form one given place to the other using sensors n stuff...i m stuck pls help <br> <br>i have bought the rover system from here just for making prototype of the actual system since i got it at a good price... <br>http://danuc.com/index.php?main_page=index&amp;cPath=6 <br>http://danuc.com/index.php?main_page=index&amp;cPath=4
Hi, I'm relatively new, I was considering putting a small camera on it and then connecting it to a ps3 controller. Any ideas how? <br>Also would it be possible to waterproof it? <br>
I'm a beginner in this so how do I put 2 wheels in 1 servo <br> <br>and is there an alternative wheel besides tamiya?

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