Introduction: Making Quality Toys From Plastic Trash: a Beginner's Guide

About: I'm Mario Caicedo Langer (M.C. for short), a Colombian STEAM educator living in Azerbaijan, BSc in Naval Sciences and former Navy officer. I am a CAD and 3D Printing enthusiast and an artist specialized in jun…

Hello. My name is Mario and I make artistic toys using plastic trash. From small vibrobots to big cyborg armors, I transform broken toys, bottle caps, dead computers and damaged appliances into creations inspired by my favorite comics, movies, games and commercial toys. It started as a hobby, but then it invaded all topics of my life and the chaos began. Sometimes it felt like a curse. Even my family asked me to focus my energy in improving my "serious" professional career and leave my passion just as a hobby; or it would take me nowhere.

But this "hobby" has taken me from Colombia to San Francisco and Azerbaijan. And thanks to my creations and my expertise in building toys using ordinary materials, now I'm technical director in a STEM education center for kids. "Nowhere" looks like a very interesting place, doesn't it?

And now I want to share with you some of the things I learned in 25 years of experience in taking some men's trash and making it this man's treasure.

I'm taking as a model this new toy I created. It's a Mech that spins its machine gun and is a vibrobot at the same time. I will not show the step by step of how to build it because is very hard to replicate the same configuration of components due their diverse origins. However, the idea is to give you some ideas so you can build your very own creation, unique in the world. Also, I will include some links to some of my previous works and creations of other makers and artists.

Step 1: Some Recomendations Before You Start:

INVESTIGATE: Internet has a lot of resources (videos, articles) from artists and makers, and certainly you can learn some techniques that will help you in your path. Besides, this hobby requires a multidisciplinary approach, so any new piece of knowledge you can get is always welcome.

GATHER: You will need a lot of materials. The best thing? You can get most of them for free. Tell your relatives and friends to keep broken toys and appliances for you. Don't throw plastic caps and other disposable things made of nice plastic away. And if you see some good plastic stuff on the street, pick it up. Soon you will have enough materials to start building your creations and even, more materials will start coming by themselves. Planet Earth has a big plastic trash problem, so you will always have plenty of materials to work with.

EXPERIMENT: It doesn't matter how many books and internet guides you read, or how many DIY videos you watch. Your best way to learn is with a hands-on approach. Only that way you can master how some materials interact with others, which tools and materials are the best for the job, how much pressure a piece of plastic can resist before breaking and which materials require special treatment. Some plastics are great to work; others will blow in your face in a cloud of dust and toxic fumes or melt, and burn your fingers.

BE SAFE: Always use dust mask and safety goggles when you are cutting or filing plastic, wood or metals, and safety gloves if you are working with power tools and risky materials. Besides, don't forget your bio-safety. It doesn't matter how nice a discarded piece of equipment looks, it's not worthy if it's placed in the middle of a hospital garbage bin. If possible, try to clean the piece with water and soap or alcohol. And don't forget to wash your hands.

KNOW YOUR PROVIDERS AND AVAILABLE RESOURCES IN THE AREA: Not all stuff will come for free; you will need to buy several tools and materials to complete your projects. Some folks get everything on eBay, Amazon and Craiglist; but I prefer hardware stores, electronics stores, thrift stores, toy stores, office supplies stores, flea markets, junkyards, supermarkets and even, drugstores. Don't forget to be nice with the hardware store staff, and they will be more than happy to help you (or to leave you alone, if you don't like to be followed on every step when you are looking for something). Also, consider not everything is as available as in America (the continent, not only U.S.). In some countries, finding cheap Chinese toys that look like weapons is very common. In U.S. and other countries, that kind of toys is forbidden and not available, but you can find a lot of discarded licensed toys with better quality and safety regulations. In San Francisco and Bogota it's the obvious rule to find PVC pipes that plug perfectly into their fittings and accessories. In Baku from some freaky reason, PVC pipes DON'T fit into their "fittings". It's a nightmare.

DESTROY: If you want to know how a thing works, take a screwdriver or break the seals and open it. Sounds like an obvious advice considering Instructables is a community for makers, DIYers and MacGyvers. But you would never believe how many professionals in science, engineering, technology, art and industrial design have never opened a pen or a toy car to check what is inside. And be prepared: probably you will spoil or completely break some very good stuff to the point of uselessness. But that's part of the learning process.

DON'T FORGET TO "KISS": And by KISS I mean the famous "Keep It Stupidly Simple" principle. Your project must be so tidy and organized you can spot easily any issue and correct it without affecting the rest of your creation. If you attach a piece, it must be done in a way it can be easily replaced when it gets broken or improved. Electrical connections should be clear. And remember: beginners use to spread unnecessary amounts of hot glue everywhere to attach pieces. Real Pros know when to use glue and when to use other attachments like nuts and bolts, screws and zip-ties.

NO MONEY? NO PROBLEM: If you really want to do it, you only need to be creative and stubborn. Money is not an excuse, because you can find great things for free if you know where to look. And if you need more motivation, check this great story of Haitian kids living in poverty but creating fantastic toys from trash.

GET INSPIRED: What do you want to build? Beautiful toys? Movie props? Sculptures? Movies, videogames, comics, TV series and retail toys use fantastic designs, and you can try to emulate them with your creations. Do you like animals? Visit a zoo and do some drawings of your favorite creatures. Like an old teacher used to tell me: "a creative person must drink from all the waters. Watch the Oscar-winning movies and the bad ones, too. Read the classics but also, bad comics."

CREATE YOUR STYLE (DARE TO BE STUPID): You are an artist. You are a Rockstar. You only need to believe it. Crazy is the new normal. Create a Power Loader for a Barbie. Create an army of silly-walking coffee-can bots. It's your art. Do whatever you want with it (as long as is legal and ethical.)

BE READY FOR CRITICISM: As I said at the beginning, my family thought I was the crazy one. But criticism will come from all sides. At the beginning of my career, some persons said my toys looked too trashy and I needed to make them look more professional. So I improved my skills and even, I took a course about movie props. Then in an art exhibition, some guy congratulated me for the quality of my work, but “suggested” I should make them look trashier, so people could recognize the materials (SERIOUSLY?). Another example: I love my robots to have awesome weapons, like Robocop and mechas from anime, but in Colombia, some acquaintances and potential partners complained about my creations being too violent and suggested possibly I had a trauma from my military times (only logical explanation, because fictional robots use flowers and the power of love to defeat enemies, right?) and I should build more “peaceful things”. But one of the hardest moments that filled me with sadness and rage was when I found one of my creations (a robot inspired by the “Batteries not included” movie) that I proudly sold months before in an ecological bazar, now over the carpet of a street seller in a third-class Flea Market in my hometown. I bought for 1 dollar; I repaired it, cleaned it and kept it with me. Now it’s part of the permanent exhibition in the “From Waste to Art” museum in Azerbaijan. And to finish, there is still the social stigma that only homeless people look in the public trash bins for useful things. It’s a dirty work and your work is trash. Deal with it.

KEEP IT REAL (AND WATCH OUT FOR EXPLOITERS): If you decide to sell your creations, one of the most complicated parts is to put a price to your own work. Some people will call you “Maestro” and said you should sell your art for thousands of dollars (big surprise: these folks never bought a single robot from me). And others will not pay even the $30 you are asking for your one-in-the-world robotic planter with LED eyes. But the worst is when they ask you to give them your creations or work for free, only with the promise of showing it to “important and influential people”, or my favorite: “just do it for love of art/science/kids”. At the end they are the ones looking good, and you still have to figure how to pay the rent. My recommendation? As Eminem in “8 Mile”, don’t quit your real job until you have your real break; and as the Joker in “The Dark Knight”, if you are good in something, never do it for free.

AND REMEMBER THE IMMORTAL WORDS OF JAKE THE DOG: "Sucking at something is the first step towards being sort of good at something.” Your first creations will be bad. Only time and experience will sharpen your skills.

Note that I'm using a lot the phrase "cheap Chinese toy/plastic/product". If well a lot of the best stuff is Made in China (like your iPhone and my beloved Xiaomi smartphone), also is the truth market is flooded with low quality Chinese products, knock-offs and materials. So, if you are from China and you feel offended, please accept my apologies beforehand and consider I'm talking about the quality of the product, not about your beautiful and respected country.

Step 2: Get and Recognize the Good Stuff

Now, if you try to keep all the plastic you got from friends or found on the street, soon your workshop will become a chaotic mess full of useless trash. So it's important you to be very selective. To choose the best stuff for my works, and use this criteria every time I find a plastic piece, a broken toy or a discarded machine:


  • Does this material look good?
  • If the piece I found looks like I cannot clean it with a reasonable amount of water, soap/detergent and sponge, I don't take it.
  • It must look easily disassemblable (assembled using screws) or at least, easy to work with.
  • Is it what you need for your project or has a good potential to be used in the future?
  • If a plastic piece looks with a lot of cracks, I don't take it. But if it's a damaged device or toy, I usually remove and keep the good components and discard the broken ones.


  • Unless the project requires that, I don't use low density plastics, like the ones of disposable products (dishware / drinkware) and cheap Chinese toys.
  • To test sturdiness, I take a plastic piece and I try to bend it a little bit. If I start seeing and hearing cracking sounds with little force, probably that piece will get easily broken in the future. And I don't want my toys to get easily broken; or me or any kid to get stabbed by a cheap plastic shard.
  • I love to work with PVC (beware: if you cut it with a rotary tool, you will have an awful cloud of dust in your workshop), PLA and medium/high density plastics. From cheap plastic I only keep small components for small decoration details.


  • Believe it or not, one great way to recognize cheap Chinese plastic from good quality one is the smell. The strongest the smell is, the poorest the quality of the plastic. Reason? Your smell sense works perceiving small particles of a material in the air. If you can smell a plastic, it means it is disintegrating quickly. Do the experiment: take a licensed Hasbro or Mattel toy or a piece of Lego and smell it against cheap Chinese toys. You will find interesting differences.
  • If a plastic piece (like a bottle or a cap) has a huge chemical smell hard or risky to remove, or come from a very stinky trashcan, I don't take it.


  • If well getting materials from trash is a dirty job, I never keep a piece or discarded device that shows a great biohazard threat. PVC plumbing from discarded toilets, hospital waste, syringes from drug addicts, materials in contact with bodily fluids, excrements or dead animals (except for for dead bugs that are easy to remove) are out of the menu.
  • Only take plastic trash when is over the trash bin or near it. NEVER explore inside a trashcan, unless it's a controlled situation and you have bio-safety protection. Avoid risky surprises.
  • If you find an interesting trashcan (like the ones in front of computer maintenance stores), but there are homeless people, suspicious guys, street dogs, rats or any other unsafe condition, go away and wait until the area is clear. No piece of trash is more important than your life and integrity.
  • By the way: it’s always good to carry plastic bags with you, so you can wrap what you find on the street with contaminating the rest of your belongings, at least until you arrive home to clean it.

Step 3: Basic Tools and Hardware

I strongly recommend you to read Robots Class by Randy Sarafan, at least the first three lessons. Even if robotics is not your thing, he shows and explains in a very effective and friendly way most of the tools and hardware, and some basic electric principles you will need for this hobby (I will focus this guide in junk art, so I will not explain basic circuits.)

The only (and very important) tool Randy is missing in his class is a good rotary tool, being Dremel my favorite brand (and probably, the best). If you need to drill, cut, file, polish, carve or destroy, a rotary tool is the answer. I have this one since 6 years ago and is awesome! And get a keyless chuck, so you can change easier your accessories. You will be invincible.

I believe you will read his class, so I will only quickly mention the basic things you need in your workshop:

  • Screwdrivers
  • Pliers
  • Pincers
  • Multitool
  • Soldering Iron
  • Hot Glue Gun
  • Scissors
  • Hobby Knives
  • Wire Cutter
  • Ruler
  • Pencil
  • Markers
  • Angles
  • Screws
  • Nuts and Bolts
  • Washers
  • Superglue
  • Zip-ties

Step 4: Harvesting Electromechanical Components From Toys

Broken toys are a good source of materials for your projects. And it's a clean one, too! (well, except for the hairs you find tangled in the wheels or axles of toy cars. Or the sulfate residues you find in the battery holder when cheap batteries have been there for years.)

Besides, if you are a beginner, components from toys are the best, cheapest and safest to create new toys. When you get more experience, you can try to disassemble old computers, printers and appliances to to create more advance projects.

The first step is to use a screwdriver to carefully remove the screws from the toy. You will find a lot of cables, gears, some electronic boards and other interesting components. There are a lot of possible references, shapes, sizes, functions and colors of components, so we will talk only about the most important ones for a beginner (for the moment, we will not talk about sound/musical circuits, remote control modules or mini-computer brains):

  • Battery holders: usually for 1, 2, 3 and 6 AA batteries; 1 and 2 AAA batteries and 1 9V battery. Even some toys, like RC cars, come with rechargeable batteries pack. Useful to provide energy to your creation.
  • Switches: if there is something annoying and anti-aesthetic, it's to turn ON/OFF your project twisting or separating two cables. Toys usually have a small switch, and often is integrated or near to the battery holder.
  • LEDs and lightbulbs: Their basic function is to bring light to the toy, and in a trash toy, they will look great as eyes. A lightbulb can be connected in any polarity and it will work. A LED has to be connected in the right polarity (positive of the battery to positive of LED, and the same with negative).
  • Motors: a motor transforms electricity into movement. It's what makes the toy roll, walk or dance. Usually they come inside gearboxes (AKA: reduction boxes), configuration of gears that transform speed into torque (more of this on the next step.) Usually motors form toys are also called "Hobby Motors" and work with 3-6 volts.
  • Cables: as probably you already know, cables conduct electricity from the batteries/plug to the electrical components. You will find cables in all presentations, colors and qualities. With time and experience you will learn which ones are the best for your projects. A hint: the best ones come from old electrical appliances, computers, toys and telephones. The worst cables come from cheap toys, not only because quality, but because usually these are too short to be reused.

Step 5: Know Your Gearboxes

So you finally removed the case from that beautiful toy car that your nephew transformed into that broken piece of trash, and you are amazed about those beautiful gears, cables and other components. When I was new in this, my first mistake was to extract the motor and disassemble the rest of the toy to its basic components. But years later I realized I was destroying the best component: the gearbox. If I had knew that, probably I could made things more advanced than vibrobots. The best thing you can do is to carefully remove the screws that attach the gearbox to the rest of the toy and keep it in a whole until you find the best use.

A gearbox (or reduction box) is a mechanism that transforms the speed of the motor into torque. Do the experiment: try to make a simple car attaching the wheel directly to the motor shaft, and you will see it spins very fast, but its frustrating how several times it doesn't have power to keep going over some surfaces. Try to do another one, adding a conveying belt. And now try this one with a gear box. Note that all the three projects work with a 9V battery. And if you try to make a walking robot, the best and only option in the context of this exercise is the gearbox.

But recycled gearboxes are not magical solutions and usually don't come in that beautiful-easy-to-work yellow box. They come in all shapes, configurations and presentations, designed specifically for the toy where they are in. Most of the time you will need to hack them. So, if you want to give some movement to your creation, it's good to know how can you use the most common electromechanical components :

  1. Motor: Because its high speed and very weak torque, you can use just the motor to make a vibrobot (the simplest of the robots) and its variations (brushbot, bristlebot and the usual insect robots you find on YouTube), using the Eccentric Rotating Mass principle. Even you can find ERM motors inside any modern joystick. Also, you can attach a propeller to create a fan for a powerboat or a toy car. You can make it look like a Gatling gun. Or if you want to push your DIY skills, you can try to create your own gears configuration, using cardboard, wood, plastic or even 3D printed ones.
  2. R/C Car Differential: This gearbox comes from (you guessed it) a R/C car. It has more torque than the motor alone, but still, its strong point is speed and it's not the best option for a walking robot. I use them for machine guns and heavier vibrobots (like the main robot of this guide). And I once built an egg-beater. By the way: R/C cars are fantastic! Simple Forward/Back ones usually come with one single average motor; if they can turn too, probably you will find two motors. But if you are lucky enough to get a professional R/C car, probably the differential will come with a more powerful motor and the steering, with a servomotor. Bingo!
  3. Simple Worm-Gear box: several small toys only need to do a not-so-fast/not-so-slow/little torque movement, and this is the best option. Usually it has one worm-gear attached to the motor and another gear attached to the axis of the toy (don't rotate it or you will damage the gearbox). Good to make small cars, but in my opinion, not the big deal. I built this thing. NEEEEEEXT!
  4. Self-steering toy's complex gearbox: Have you ever seen that kind of toys that look like cars or trains, go forward and turn without any command? And then you check bellow and discover that two small wheels inside a cylinder are responsible of this movement, and not the big decorative wheels at the side? Well, this is the gearbox responsible of that movement and in several cases, they can animate other parts of the toy. These gearboxes are complicated to hack, but when you do it, you can make things like this small robotic dog.
  5. Speed/torque double function gearbox: Oh, I love to hack this one! Usually you find it in bubble-shooters and in the hard-to-find-in-America electric toy weapons. The motor is in the middle. One end of the shaft is connected to a gearbox for operation that requires some torque (like pumping soap-water). The other end has a fan attached (like a blower to create the bubbles) or any other mechanism that requires speed. It's good for making some automata like this and this.

  6. Crankshaft gearbox: These are the easier to hack and use from the toy gearboxes in this guide. You usually find them in walking toys, like dogs, babies and robots. The only problem is the moral and ethical implications of destroying a walking toy to build... another walking toy. Actually, I prefer the Burhan Saifullah approach of transforming a toy car into a crankshaft for a walking robot.

  7. Servomotor: as I said in point N.2, I found this servomotor in the steering mechanism of a R/C car. Servos are very versatile and can be used in more advanced applications. However, if you only want it as a gear box, probably you can learn how to remove the controller here.

  8. Automaton gearbox: if you see a big toy with anthropomorphic or animal shape, that dances or moves several parts of the body at the same time, there are two options: or it's a real robot (probably it has sensors and/or remote control, and several small gearboxes or servos); or it's an automaton: all the movements are controlled by a complex gearbox powered by a single motor. Usually these gearboxes have good torque and low speed. However, it's complicated to fit this bulky component into your project or hack it to make it more usable. I'm starting to consider disassembling this one to use only the motor...

  9. Standard DIY gearbox: now, if you are not in mood of experimenting with all the previous examples, it's complicated to get cheap broken toys in your area or simply you want to start with something simple, easy and powerful, you can get the yellow reduction boxes hobbyists use for Arduino projects. When you have more experience, you will find all the variety of gearboxes you can find in the market.

To finish with the gearboxes topic: if you try to rotate the shaft of a gearbox and it doesn't move, don't try harder, or you can break it. Plastic gears (specially from cheap toys) are fragile; and if the gearbox works with worm gears, it will be worse. The best option is to power it with a battery.

Step 6: Choose a Project and Plan How to Make It!

Everybody believes I follow the Engineering Design Process, the Design Thinking framework or any other "Design Something Something" that involves:

1. Ask: How to solve a problem/ create a product?

2. Brainstorm: make a list of ideas and choose the best ones.

3. Design: make a drawing or plan of your project.

4. Build: put the pieces together.

5. Test: turn on your project and check how it's working.

6. Improve: correct mistakes and try again.

It's a great approach. But I have to be honest, several times I don't follow these steps when I make my art. Sometimes I start with a great idea, but at the end I finish building some other thing that came to my mind in the middle of the process.

Sometimes I work in an idea, it fails over and over and over. And when I gave up after several test and improvements, I decide to change the point of view and transform it in another thing. As an example, I started trying to make a 4-legs walking robot, but the gear box was week, so I transform it into a crazy dancer.

But usually, when I want to start a new project, there are two origins:

  • I want to build something specific and then I start with a scavenger hunt to find the pieces to complete it.
  • I have some good piece and I start wondering "Mmmm... what could I make with this?", then I start working on it until I create something I like.

Now, when you define what you do want do do, there are several ways to design your creation. You can choose the one that fits you better:

  1. You can use a design software, like Tinkercad or Fusion 360.
  2. You can go for the classical option: a trustful notebook with a pencil (it's a good idea. Curiously, I started to used it just from a few months ago.
  3. My favorite: I sit on the floor with a pile of trash and I start working it as a puzzle. I put the pieces I consider the best for the main body, then for each arm and leg, then for head and accessories. At the end, I take a photo, to keep my mind working in the design when I'm in the bus, and in case my cat destroys it.

Usually I don't throw my "failures" to the trash. I recycle them, throwing the broken parts and keeping the good ones to use them in future projects. In the case of the robot I'm using as an example, the front part with small arms comes from a previous project (a walking robot) that got broken. And now it fits perfectly this new toy!

Step 7: Building Tips

  • Use high quality plastic or metal for the articulations and structural parts of your robot. Low quality plastic is better as decoration or non critical points.I use screws, nuts and bolts for the joints.
  • Metallic washers are great to use with nuts and bolts and with screws. They increase the surface contact between these and the plastic, increasing friction in joints and reducing the risk of ruptures in that area of the plastic.
  • When you move a joint of your robot, probably it will start unscrewing the bolt and the piece will get loose. To avoid that, you can tighten the nut and then put a small drop of superglue between the bolt and the nut, being careful of not adding too much, or your joint will be spoiled. This solution is great for nuts and bolts in vibrobots, that usually get loose because of vibration.
  • When you need to use the rotary tool to drill a hole for a screw or bolt, start with a drill-bit thinner than the screw, test, and then, change it to the next size of drill until you find the perfect hole. Screws need tight holes, nuts and bolts usually require loose holes.

Step 8: Test and Improve Your New Toy

You must be prepared for something: the first time you test your new toy, probably it will fail. It doesn't matter your experience, your professional background or your skills. It will fail (probably).

But that's part of the magic! You will be in a "test/improve/test/improve cycle" until you get a toy that makes you happy or you throw it violently to the floor in frustration and despair. Then you will believe you are good for nothing, turn off the Dremel, clean the floor and lay in the sofa to watch the next TV show. Who needs this stupid hobby when the couch offers you a better way to pass your leisure time?

And then, a few days later, you will return to your small and improvised workshop to clean it. You will grab a broken toy to throw it to the trash bag. But then you decide to open it, to check how it is inside. When you realize, you are sitting in your crafting table, dissembling it completely, trying to combine the parts with other plastic pieces, connecting cables to see how the motor works, you don't know if it will work, but you are passing a nice time, only you and your tools...

Congratulations! That's your graduation, colleague! May this hobby bring for you the same blessings it brought to my life, and even more!

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