Introduction: Cardboard Robot With Pop Tab Circuit

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    Make your own little light up friend with this cardboard robot & simple circuit tutorial. If you're a little apprehensive about making things three dimensional, just want a little guidance or some tips on working in 3d with cardboard this Instructable is made for you. You'll also learn how to make a simple- no solder- circuit for your robot.

    A bit about circuits:

    You are making an electrical circuit. Electricity is the flow of electrons & an electric circuit is a circular pathway electrons can flow through. If the circuit is open, there is a break in it, the electricity cannot flow through. The circuit has to be closed, a complete circle. (see Photo 5) Your circuit has a switch. A switch is something that makes or breaks connection in an electric circuit. When the switch is off, it makes a break in the circuit and the electrons are not able to flow around. When the switch is turned on, it closes the gap and the electricity is able to move and make the device work.

    Electricity only flows through conductive materials like metal. Electricity will not flow through some materials, these are insulators. Tape is an insulator. It will be important to pay attention to these things while you build the circuit.

    Your LED, or Light Emitting Diode, has two legs- a short one and a long one. The long one is the positive (+) leg & the short one is the negative (-) leg. These are important because the electricity only flows through the LED in one direction; from the positive (+) side of the battery through the positive (+) leg, through the LED's head & back down the negative (-) side. (see Photo 6)

    Test your LED & battery by directly attaching them (Photo 7). The LED's legs will go on either side of the batter, like a battery sandwich with the LED legs as bread. Make sure the positive (+) and negative (-) sides are matched up.


    Main materials: These materials are for making the body of your robot.

    • Cardboard
    • Scissors or Shears- scissors will work but shears make cutting cardboard much easier
    • Pencil
    • Hot glue/tape- to attach the cardboard pieces together
    • Optional- Canary Cutter for cutting down boxes

    Detail materials: These materials are for adding features and details to your robot it's up to you what you use but here are some examples.

    • Adhesive (if you want to use something other than your hot glue/tape)
    • Beads, gems, buttons, googley eyes, paper clips, decorative tape, markers, +++

    Circuit materials:

    • Pop tab
    • LED
    • Coin cell battery
    • Brass brad
    • Optional: Pliers to help bend the pop tab

    Step 1: ​Cut Out the Head & Torso

    If your cardboard has a good side & bad side, use the bad side to trace out your head and torso shapes & cut them out. Don't worry about arms, legs, etc. we'll make those later on. For the photographs above our good side is the pink side with writing.

    Flip your cardboard over and trace out the shapes onto another piece & cut them out. This will give you two mirror image heads & torsos like in photo 3.

    It's a good idea to keep your cardboard scraps handy so that you can pick out little pieces you may need later on. You can keep them in a container lid or plate so that when you're all done it's easier to dump the unused scraps into the recycling bin.

    Step 2: ​Make the Sides

    Since we're making a 3D robot the head and torso are like little boxes. They need a left side, right side, top and bottom. You can cut those out as thinner or thicker sections based on what you want your robot to look like.

    Make the first side piece:

    Take your robot's face and lay it next to a piece of scrap cardboard, lining it up with the bottom, and make a mark showing how tall your right side needs to be. It needs to match the height of your robot's face. Now you can draw out the rest of the right side based on how thick you want it to be. (Photo 1)

    Make the other side pieces:

    Make the left side the same way- by laying the face next to a scrap piece of cardboard & making a mark to the right height. You can use your right side to help measure the width- in the photo (#2) it is the piece that's below the cardboard scrap. (Photo 2) Once you have both side pieces you can lay them out like in Photo 3.

    Make and add your top and bottom pieces, then you have all the parts for your robot's head. (Photo 4)

    Make the robot's body the same way you made the head.

    Step 3: ​Assemble the Head

    Now that you have your pieces made and laid out you can start to assemble your robot's head into a box. Hot glue is preferred (& shown in the images), but you can also use tape to put the pieces together. Put a bead of hot glue along one edge of the face, then take the corresponding side/top/bottom piece and set it onto the hot glue at a 90 degree angle (meaning it is making an upper case "L"). Be sure to hold it in place until the glue is cooled and it stays on it's own.

    Add the second side/top/bottom piece & let it cool until secure. Now you need to reinforce it with glue in the corner. (If you're using tape, add a piece of tape that goes around the outside of the corner to hold the two pieces together).

    Keep repeating this process until you have all 4 sides attached & their corners reinforced. Add on the other face piece by putting a bead of hot glue along the top edge and then pressing down until it's cooled. You now have a three dimensional robot head!

    Don't assemble the robot's body yet, since we're adding a circuit we have a bit more work to do on the torso. body.

    Step 4: ​Add Details

    Now that you have the main parts of the robot done you can dress them up with your craft supplies & recycled materials.

    TIP: If you're gluing something very small it's safer to put the glue on the robot first and then place the small item onto the glue- that way you're not getting your fingers really close to the hot end of the glue gun. See Photo 2 with glue being placed on antenna tip & the small bead is placed onto the glue to save fingers from potential burns.

    Step 5: Prepare the Torso for the LED

    To get the torso ready to house the LED you need to make two holes the same distance apart as the LED's legs. You can use a pencil or push pin to make the holes in the robot's chest. The use your pencil to trace the holes onto the robot's back. Punch those holes too.

    Test fit your LED;

    You should be able to push it through both the chest and back like in the last photo.

    Step 6: Prepare the Torso for the Pop Tab

    Your pop tab will be used to keep the LED turned on. It will need to swivel back and forth so that it is sometimes touching the LED and sometimes not touching it.

    Looking at the robot's back you will see the two LED holes, lay the pop tab so that the larger, oval opening is laying on top of those holes. Mark the smaller part of the pop tab with a pencil, this is where you will make a third hole. This hole will be for the brass brad so that it can hold the pop tab in place but still let it rotate.

    You can now add the sides of the torso, but not the top (chest) yet.

    Step 7: Attach the Pop Tab

    First you'll need to bend the pop tab a bit so that the oval part is curling down like the first photo. You can do this by hand or use pliers.

    Attach the pop tab to the back:

    Our brass brad had a head that was a bit too small, when we put it on the pop tab the tab just slipped right through. To solve this we made a cardboard washer that kept this from happening. You may or may not have to do this. Once you're ready, attach the pop tab to the robot's back with the brass brad. Make sure it rotates freely without falling off. You can tape the legs of the brad on the underside of the robot's back to make sure they stay in place.

    Step 8: Close the Torso

    Add the LED into the chest of the robot and line up the holes so that the LED legs are pushing out of the back just a bit. You can pinch the bottom to the torso to help hold it in place. Add some glue to the top half of the torso and hold it closed while it sets. Make sure the LED's legs have come through to the back. After that glue is set, do the same with the lower part of the torso so that the whole thing is glued together.

    Step 9: Finish the Circuit

    Now to place the LED's legs where they need to be & add the battery step by step.

    Negative LED Leg:

    Bend the negative (shorter) leg of the LED down to the left so that it rests on the cardboard (Photo 1).


    The negative side of the battery will need to lie on top of the negative leg of the LED, covering it entirely. Tape the battery so that it is securely down on the cardboard but also so that there is room to lay the positive LED leg on top of it still. The positive leg of the LED has to touch the battery itself for the electricity to flow, it cannot lay on top of tape.

    Positive LED Leg & Pop Tab:

    Now lay the positive leg of the LED onto the battery (you'll see the LED light up) & swivel the pop tab on top of it so that the LED leg is pinched in place.

    Hello World! You made a simple, no-solder circuit!

    Step 10: Add Arms & Legs

    If you've got some larger pieces of cut cardboard you've been saving this is a great time to use them. Cut test arms and legs and lay them out to make sure you like them, adjust as needed. To give them a little more dimensional you can layer multiple pieces of cardboard on top of each other- add some felt for a pop of color.

    If you want your arms or legs to come out at an angle you can cut the ends (Photos 3 & 4). Be careful, if your legs are at too much of an angle your robot may not stand up well. Arms and legs take a bit of time to set in the right position as the glue cools, you may need to hold them in place for a minute.

    Your robot may be able to stand on its own or you may need to glue its feet to a surface to hold it up.

    Now you can make more robot friends!

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