Building robots with cardboard
Who are cardboard robots for?
CARDBOARD ROBOTS is a set of free robot plans and building techniques easy to replicate worldwide with recycled materials and basic electronic components. Designed to be made at school with students aged from 10 years old and up.
Our goal is to make cardboard designs as useful as possible for teachers and educators worldwide. We keep our designs basic so students can build them within limited time frame at school. We propose to use only easily accessible, free (cardboard) when possible, or reasonably cheap (Micro:Bit) materials and components that are available worldwide.
Sustainability is a welcomed side-effect of this approach. Our robot designs contain mostly recycled and recyclable materials and connecting elements are reusable (nuts and bolts and rubber bands).
Design principles
Simplicity
Cardboard robots are designed for school use thus we always put function over form and try to make the constructions as simple as possible. We are familiar with time constraints of regular school lesson and what you can actually achieve with teenage students in short time.
Accesibility
Cardboard robots is not another STEAM robotics kit. We design free robotic plans and good practices how to use it at school. We propose only tools that are available and easy to source worldwide.
Since for any robot you need a minimal set of electronic components you have to source yourself we try to use as little of them as possible and only components that are widely available worldwide such as BBC Micro:Bit and regular servo motors.
Opennes
One of the greatest advantages of working with cardboard is a fact that you can modify it any way you want. Use our designs to jumpstart your students creativity and encourage them to find their own way. Engineering type students can work on mechanical problems, storytellers can personalise their robots appearance with any crafty material.
Why cardboard?
Cardboard is a fantastic construction material, hugely underestimated and undervalued as in our everyday life we mostly see it as short living packaging to quickly land in trash.
- It is virtually FREE (if you save it from being thrown to trash) and easily available worldwide
- It opens your imagination — as soon as you get used to cardboard`s properties and learn to model it, your creativity starts to sparkle with construction ideas and new ways to express your visual taste
- You can build small and big — no other construction system will give you this — LEGO is gorgeous but try to build build a two meter tall castle out of it. With cardboard you can build small figures or HUGE statues, however you want
Why BBC Micro:Bit?
Since building robots requires some kind of programmable controller we had to choose one that fits our principles:
- Is easy to use and school friendly
- Has basic robotics capabilities — some sensors and driving motors
- Is affordable and available worldwide
The decision was in fact quite easy as BBC Micro:Bit board fits our guidelines perfectly and over last few years had grown very strong educational community.
Who made it?
CARDBOARD ROBOTS idea was created by Maciej Wojnicki founder and creator of LOFI Robot
Building manual
How to start
- Choose the robot and download design file
- Print the design file — remember do not scale it! set printer to print without bleed margin
- Glue the design card to cardboard, wait for the glue to dry and cut out the parts — remember black lines are to be cut, dashed red lines are to be bent
- Assemble the robot with nuts, bolts and rubber bands with a help of the screwdriver
- Attach motors and Micro:Bit to the construction
- Code the robot in MakeCode — you can find example code in our manuals
Cardboard
As you have probably noticed by now cardboard is a thing we pay attention to here
So we think that cardboard is good enough for robotics — REALLY! It is strong enough, it is easy to make models with, it has its limitations but in an educational environment it is not a bug — IT IS A FEATURE. Robotics is about solving problems and working around your hardware limitations.
Look around you — you will surely find great supplies of free cardboard to reuse so do not by another plastic toy — get creative with what you have on hand
Below you can find some tips and tricks how to work with cardboard in school with your students. These are not strict rules but field tested good practices, if something else works with better with you and your students LET US KNOW!
Cardboard types
Best type of cardboard is a one layer 3mm cardboard you can find it in small and medium boxes usually food packaging, shoe boxes etc. It is easy to cut with scissors and bends nicely.
Thicker cardboard as two layer 6mm you can see in the picture above is to tough for kids to cut with scissors and is hard to bend. It can be found in fruit and vegetable crates in grocery stores. It is hard to make models out of it but can be useful for elements that require stiffness as wheels.
Cutting cardboard
We suggest cutting cardboard with good quality scissors as it is a method safe for kids. You would surely get a cleaner edge with a proper utility knife but for safety reasons you had better not give them away to your students, unless you know what you are doing
Bending cardboard
Making connections
As a main method of making connections within cardboard elements we suggest using screwdriver for making punctures and then twisting it with nut and bolt. This method provides strong and rigid connection, is very easy to make even for small kids with some practice, you can disassemble the connection and fix it easily. Also nuts and bolts are endlessly reusable.
PRO TIP — for some quick prototyping and testing you do not even have to screw the nut on the bolt. The bolt thread will keep the cardboard connected for a while.
Cutting holes
Puncture the cardboard in four corners of the rectangle hole you want to make, this will give you a tracing points for scissors cuts on both sides of the cardboard sheet.
Tools you need
1. Screwdriver
Main assembly tool for cardboard robots used for nuts and bolts and making punctures in the cardboard.
We recommend using 10cm long screwdriver with PH0 phillips tip best for M3 nuts and bolts. It is also more comfortable to use a screwdriver if its handle has rotatry tip.
2. Scissors
Use good quality scissors for with fairly sharp tip to cut the cardboard and making bending traces.
3. Nuts and bolts
In our design process we found out that M3 nuts and bolts we were using in our previous LOFI Robot wooden construction system are a great way for cardboard constructions as well.
Main advantages of nuts and bolts:
- Provide sturdy and firm joint
- It is easy to make corrections and take a step back in your assembly process — reduces building stress
- Reasonably cheap when bought in quantity
- Reusable and almost indestructible — unless your students will eat them, you can reuse nuts and bolts millions of times
- Clean connection — does not make mess as glue and adhesive tape
PROTIP!
Use screwdriver to puncture the cardboard and make holes for bolts. It requires some practice but with proper guiding this assembly technique is accessible and safe even for small children.
4. Rubber bands
Standard rubber bands are a great thing for putting things together and greatly speed up prototyping with paper. Rubber bands are easy and fun to use even for small kids, encourage play and boost creativity. Furthermore parts assembled with rubber bands can be reasambeled as many time as you want which takes down fear of failure and encourage experimentation.
Advantages of rubber bands:
- Easy to source from recycled packaging
- Cheap to buy in bigger packages
- Reusable
- Clean work
- Fun and inspiring to use
Do not use glue or adhesive tape!
Usually wherever you find building instructions for paper models, you are guided to assemble them with paper glue, glue gun or any type of adhesive tape.
We encourage you not to use them becouse they are:
- Messy — your hand get dirty, paper gets dirty, everything get dirty with glue
- Glued connection is irreversible — you can not take a step back and review your idea — this rises design and assembly stress
- Needs refill — paper glue and adhesive tape is not so expensive still it is a cost to refill your supplies from time to time
- Glue takes time to dry and stiffen — lesson time is to precious to waste
Electronics manual
Minimal set of electronic components
To get started with cardboard robots you need a really small set of electronic parts:
- BBC Micro:Bit
- Servo connector (female) to three alligator clips adapter cable
- 2 x AAA battery pack — with AAA alkaline batteries
- One servo motor — depending on the project 180deg or 360deg (so in fact you should have two of them, but only one can be connected at a time)
With this setup you can get a really cheap robotic kit (cost altogether around 25USD) that will allow you to make all of our one-motor projects.
With a help of the adapter cable you can connect the servo motor directly to the Micro:Bit, even tough the board can provide very little power directly from the 3,3V pin (about 90mA) it is barely enough to power one micro servo.
PROTIP — Micro servos with plastic gears (usually in blue housing) require less energy than the one with metal gears (usually in black housing like Tower Pro MG90S) — so if you plan to power it directly from the Micro:Bit board choose the plastic blue ones
PROTIP#2 — If you power the board with AAA batteries you have to use ALKALINE BATTERIES they provide 1,5V each so two of them give you 3V which is already below required 3,3V but will get the board and one micro servo running for quite a while. Regular AAA Ni-Mh rechargable batteries like Eneloops etc. provide only 1,3V each so two of them give only 2,6V which is not enough to drive the servo.
Suggested electronic parts
- BBC Micro:Bit
- Micro servo motors — two types -180 degree and 360 degree (full rotation)
- Micro:Bit adapter to connect servo motors
- Magnetic micro USB cable
1. BBC Micro:Bit
We love Micro:Bit since its introduction in 2016 and now as it grown mature with software, users community and educational content it is a no-brainer to make it a heart of an educational-centered STEAM project.
Micro:Bit is much more capable than Arduino and much simpler to use than Raspberry Pi. Packed with built in sensors and wireless connection capability this board is great for a basic robot controller.
Micro:Bit has plenty of onboard sensors:
- buttons
- accelerometer
- magnetometer — compass and magnet sensor
- light sensor
- thermometer
- capacitive touch sensor
- analog pins
For basic robotics projects you can easily go on with the builtin sensors so you need no extra accessories for the board.
2. Servo motors
The only external components you need to build a simple robot with a Micro:Bit board are motors. We suggest using only micro servo motors as they can operate on 3.3 volt signal provided by the Micro:Bit and you can get them in two modes:
- 180 degree — for pivots, gripers, arms etc.
- 360 degree — full rotation — for wheels
3. Micro:Bit adapter
The only limitation of Micro:Bit is that you need some kind of adapter to connect motors and provide power supply. For the sake of simplicity we suggest using adapters listed below:
- Elecfreaks ring:bit V2 (suggested)
- Kitronik SERVO LITE board
If you have basic electronic experience you can workaround and connect servo motors to Micro:Bit without the adapter, or make this kind of board on your own.
Other adapters
There is of course a huge choice of more capable Micro:Bit adapters with much more features. For the sake of simplicity we suggest only basic solutions with micro servo and we find smaller adapters with less features more suitable for basic school needs. To go on with any other adapters or Micro:Bit extensions you will have to make some modifications in our robot designs,
4. Magnetic micro USB cable
This accessory is not necessary but it is ESSENTIAL to lenghten your Micro:Bit board lifetime in school environment when it is tossed around from one kid hands to another.
Micro:Bit is rather solid board with now specific parts to bend/break/tear apart but it weakest point is definitely a MICRO USB PORT. Makecode software uploads the code only via usb cable and as you build a moving robot you will likely want to plug and unplug it many times uploading new iterations of your code and testing it. When this process is in hands of your inattentive teenage students damage of the usb port is only a matter of time.
Magnetic cable solves this problem, you only plug the connector to the usb socket once and then use the magnetic plug to connect the board to the computer. If your robot falls to the ground or moves unexpectedly, magnetic plug detaches and keeps the usb port safe.
For more robot plans, building tips and lesson plans go to: https://cardboard.lofirobot.com/
