Introduction: Arduino-Controlled Wolf Tail

About: I have always loved wolves and feel a spiritual connection with them. All my life I have aspired to become one with them. It all began with a visit to a wolf sanctuary where all these wolves came close to me a…

Greetings, or should I say, "Aaaaaooooooooooooh!" Pleased to make your acquaintence fellow wolf enthusiast. You have an inner wolf spirit that is so eager to make themselves known that you have come me to learn how to make your very own animatronic wolf tail, so that you can truly let your inner wolf go wild and wag that tail of yours, or soon to be tail. Now now have patience little one...down wolf down! Dowwwn!! SIT!!! Good before we start to make your tail you first need to purchase a lot of supplies. Why are you cocking your head? You can't make a tail without materials right? You will be spending around $100 for this tail so here's what you'll need:

-2 Klixx Balls/Links (The more small pieces you have the longer your tail can be)
-2 Bicycle Brake Cables
-2 Boxes of Jumbo Paperclips
-1 Continuous Rotation Servo with "X" Head
-1 2" Flat-End PVC End Cap
-22g Hook-up Wire (3 different colored wires make for easy identification)
-Arduino Uno Microcontroller
-Fur (I used Rabbit Skin on mine)
-Sewing needles and thread (I hand-sewed the fur for my tail; however, a machine will be much faster and more consistent)
-Soldering Iron
-Solder (A lot of solder)
-Exacto Knife
-Dremel with Drilling Bits
-Needle-nose Pliers
-Cutting pliers/sheers
-Super Glue
-Painter's Tape or Masking Tape

Got everything on the list? That's a good wolf! Now you are ready to make your own animatronic tail! I know it's exciting but don't get too excited now, you got a lot of work to do. Cheer up little one, a little work goes a long way and besides, time will go by quickly and you'll be wagging that tail in no time at all! Let's begin!

Step 1: Building the Tail Spine

Okay so what makes a tail move? A spine, correct! Take your Klixx toys and pull apart all the little pieces. I like to keep my colors separated, so once you have done that, take a closer look at the inside of one of the pieces. You see the two little knubs sticking out a bit from the inside walls? Those have got to go so grab that Exacto Knife and carefully cut off those little knubs (Please if you are a wolf cub allow your parents to do this for you). After you cut off all those knubs place two pieces together and move them back and forth. Hear anything? No? Great! Now then, turn them over so that the single flat end faces you. Clamp them down tightly and drill a hole all the way through. Take the drilled out piece and place it on top of the dual end of another component. Mark where the hole is and drill through both ends. Repeat this for all the pieces you plan on using for your tail.

Now comes a fun part; take your box of paper clips and take one out. Unbend that paper clip, cut it to half-length and carefully thread it through both holes. Bend both ends in making an eye-loop. Move the pieces together and wala: movement! Thread paper clips through all the Klixx pieces and you should have a single, long, moveable tail spine. You will want to fix the paperclips so that they no longer slide back and forth within the Klixx. I used SuperGlue to take care of that and so should you. Now see how easily you can manipulate the spine back, forth and around? Time to get that movement under control.

Take your bicycle brake cable and cut off those stops at each end (Again parents should take care of this as the ends will be quite sharp. You will want to wrap those ends in tape so that you do not cut yourself up like I did). Thread the bicycle brake cable through one side of the spine and then down the other. Turn the tail over 90 degress and thread the other bicycle brake cable through the other set of paper clip eye-loops. Test time! Hold the base (not the tip) of the tail in one hand and with the other pull on one of the cables. The tip will be pulled in. Now push that same cable. The tip moves in the opposite direction. Congratulations! You have a moveable tail spine! Now that this has been built, we need to get to work on the animatronic part of this tail. Don't worry now, you're halfway there! Onto the servo!

Step 2: Building the Tail Controller

Okay, so now we need to make this tail move on its own. That's where the servo comes into play. But first, we need to work on the PVC end cap. Now the current size is just way too big for our needs. Clamp the PVC onto something sturdy and mark a line half an inch from the closed end (Parents you're up again).  Saw off the open end and you should be left with the now narrow closed end. You'll need to mark the exact center of the inside of the cap and usually you can see the center dot where the thread markings eminate from. Drill a wide hole through the end cap. This needs to be large enough for the mounting screw of the servo to fit through. Speaking of which. grab that servo and unscrew the mounting horn.

Place the screw somewhere safe, you'll need it later. Position the center of the horn over the hole you just drilled. Mark points onto the PVC where the furthermost holes extend. Drill those four holes after taking off the horn of course. Position the horn back in the PVC and take small cut paperclips and put them through the holes, bending the ends in to secure them in place. You should now have the horn fixated to the inside and immobile. You do? Such a smart wolf! Now you'll want to mark two holes close to each other on the outside rim of the cap. Drill those out too. These holes will serve as place holders for your bicycle brake cable ends. Attach the main servo body to the horn and screw them back together. Now to get that cable through. Take your needlenose pliers and bend the ends of the cable in to make a sharp corner. Put the ends into those two holes you just drilled and take some more small paperclips and force them into the holes as well. Bend the ends to keep the cable in place. You want the servo to be close to your tail but not touching the spine. Leave an inch gap. Now for some soldering! Yay! (Please note that a soldering iron can reach around 800 degrees Fahrenheit thus if you are new to soldering please please Please either have someone with more experience do the soldering or have someone guide you through it.)

Unbend a lot of paperclips, you're going to need a lot. You have to solder a cage around the whole servo component, leaving a little space for the cable and cap to move around. You can solder any style of cage, but if you really want a good example go to and click on the "How To" Link. It is under the "How To Build An Animatronic Tail Actuator". Start by solder a box around the servo body. Then a clip to the underside of the servo crossing over the box clips. Then just go from there. The cage should be sturdy enough to protect the cables and cap while also allowing the cable to move freely around. Once you have the cage built, test the movement of the tail again. If you notice the cable slipping off  the endcap, have no fear. All you need to do is solder some guides to the cage. These guides have eye-loops just like the paperclips you threaded through your tail spine from earlier. Solder a couple and try moving the tail again. Add more if you need to but remember, keep the guides as far away from the cap as possible; if they are too close they will impede the movement of your tail. Now we wouldn't want that now now would we? Once you got the cage and movement sorted out, you need to do one last bit of soldering, a belt loop. Solder this to the back of your servo. You want the closed end of the cap to be facing out when you were this. All done? Good wolf! Now for the last step for your animatronic tail, programming it. Come on, this way!

Step 3: Programming the Tail Controller

Okay, so you have built the spine, built the controller, connected the two, you're almost done! Now we must program the servo to wag on its own. I have used the generic "Sweep" sketch from the Arduino website and slightly altered it to work with the continuous rotation servo. As you can see, it runs in a loop back and forth, just like the wagging of a tail, right? Go ahead and upload this sketch into the Arduino Uno board, making sure you have downloaded the servo library as well from the Arduino website ( :

#include <Servo.h>

Servo myservo;  

int pos = 0;    

void setup()

void loop()
  for(pos = 0; pos < 180; pos += 1)  
  for(pos = 100; pos>=1; pos-= 1)     

Uploaded? Great! Now take some of your hook-up wire and connect one set of ends to the output wires of the servo and the other ends to the Arduino. Make sure that the wire connecting the black wire of the servo goes to the Ground pin of the Arduino, wire to the red servo wire to the 5V pin, and wire to the white servo wire to Digital Pin 9. Plug in your Arduino to the computer after hooking everything up and your tail should start moving on its own! Now all that is left is for you to give that tail a realistic look so grab your sewing kit!

First though, take your pantyhose leggings and cut the leggings off. Put one legging over the tail and the second one over that. Now we can put some fur on that tail. I sewed a simple tube while it was inside out then turned it right side out. Pull your tail through your fur tube and sew it secure on the top over the servo housing. You want to make sure that the tube is not too tight as that will impede the movement of your tail. You  did it! You made your very own animatronic wolf tail. Now just cover the tail with the fur of your chosing and wala: you got yourself one beautiful realistic wolf tail! One last last step, get a belt, thread it through your tail's belt loop, put on the belt, and go show off your inner wolf!

A note of caution: be mindful of your surroundings, your tail has the power to break something or hurt someone so please, be careful. I am not responsible for your breaking of something priceless. Have fun! "Oooooooooooowwwwwwwwhhhhhhhhh!"

Step 4: What's Next?

So now that you know how to make an Arduino-controlled wolf tail, there is so much you can do. Here's just a few:

-Play around with the Arduino sketch and change the delay values to alter the speed of the wag.
-Follow WolfTronix's dual servo controlled tail at their site (
-Or, if you are really craving something truly spectacular, follow my blog ( as I attempt the impossible: A Mind-Controlled Tail!!!

Happy wagging my friends!

                                                                                                                                                Your Fellow Wolf Enthusiast,

Umberfur  (a.k.a. - Emily Duerrwaechter)

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