Introduction to Robots

Welcome to the Robots part. In this part, we are going to explore what makes a robot a robot and then make some simple robots using DIY electronics and paper engineering.

Robots are machines that do a set of things automatically, meaning that they act without humans directly controlling them. Robots usually have a set of inputs, a set of outputs, and a “brain.” An input is thing that triggers something, such as a sensor or a switch. An output is something that does something, such as lights, sound, or movement. The “brain” of a robot is designed to act, sense, or react. Most robots these days are controlled by computer program “brains” on microcontrollers or computer chips, but you can also make robots react to sensors and trigger outputs using circuitry and electronics.

The world of robotics is changing fast. You can find robots in every part of the world doing almost any kind of job you can think of. Robots work in factories building, delivering, and checking products. Robots explore places hostile to humans, such as the deep sea or sites with dangerous nuclear waste. Robots even look after elderly people and children. Do you think there are jobs a robot can’t do? What about creative jobs? In this part, we’re going to make a Modern Art Robot to test our assumptions about creativity and automation. What do you think now? Can a robot make art?

Because this is probably the first time you’ve made a robot, I’m going to be keeping our first robotic projects very simple. We are not going to be using any code or logic, but if you want to go further and make robots with code and electronics, here are lots of great beginner microcontroller “brains” made especially for robotics. Check out Crafty Robot’s SmartiBot, Adafruit’s Crickit, or the BBC Micro:bit for the next stage of your robotics journey.

Robots can do all sorts of things, but over the course of this part, we’re going to concentrate on one of the most exciting outputs in robotics—movement! We’re going to use motors for the first time, figure out how to change the movement of our robots with design, and then make a paper engineering automaton. Here’s where to find this information:

Robots: Essential Skills

   What are motors? (page 198)

   How to choose and use motors (page 203)

   How to experiment with your robot’s movement (page 217)

   How to use cams in automatons (pages 232–233)

We will also learn how to use a new DIY electronics tool in this section and find out about making circuits with wires instead of copper tape or conductive thread. Here’s where to look up this information:

   How to use wire for the first time (pages 198–199)

   How to use a wire stripper (page 204)

   How to choose and use different wires (page 222)

Robots: Essential Skills

What Are Motors?

There are lots of different inputs (things that trigger something) and outputs (things that do something) that you can use in robotics, but we’re focusing on motors and movement.

We use motors for movement, from making robot arms wave to driving cars. We’re going to be using a type of motor called a direct-current (DC) motor. You can’t control DC motors really precisely, but you can get them to spin really fast, making them good for movement. We’ll be hacking some little 3V DC motors into vibration motors to get our simple robots to move. A vibration motor is a type of DC motor with an unbalanced weight on one end.

Motors can require a lot of power. Some need to be wired up in a special way with other components, so you do need to be careful about which ones you buy. The little motors we are going to use are powerful enough to make our robots jump around but not powerful enough to move anything heavy. This is because our motors can spin really fast, but they don’t have a lot of torque, or turning power.

How to Use Wire for the First Time

So far in this book we have used copper tape and conductive thread to make our circuits. However, sometimes the best option for making a circuit is wire. Wire can be made of lots of strands or of one solid core. Stranded wire is more flexible, but solid-core wire is easier to use. You can also get different thicknesses of wire. For DIY electronics projects such as the ones in this book, I usually use 22 American Wire Gauge (AWG) stranded wire, but it doesn’t really matter if your wire is a little bit thicker or a little bit thinner. To use wire to connect your components, you’ll need to use a wire stripper. This part will give you plenty of practical experience with this tool, but here are the basics of working with wire and wire strippers.

A wire stripper is an essential DIY electronics tool. Wire strippers do two things: they cut the plastic bit on the outside of the wire, and then they remove the unwanted section of plastic coating. A wire stripper has a few different sizes of holes to fit different sized wires. When you close the wire stripper shut, these holes act like teeth to cut the plastic coating but leave the wire on the inside intact.

To prepare a wire for use with a component, put the wire inside one of the holes on the wire cutter, and close it at the point of the wire where you want to strip the plastic off. With your other hand, hold the wire on the component side. Keep the wire strippers shut, and pull them toward the cut end of the wire. If you’ve chosen the correct sized hole, this action will cut and remove the unwanted plastic coating. If it doesn’t work, try a slightly smaller hole size.

Take the exposed wire, push it through the hole on the component you want to connect it to until most (but not all) of the bare wire is through the hole. Pinch the wire with your fingers so that it bends back on itself, making a loop. Wind the loose end of bare wire tightly around the bare wire on the other side of the loop, making a secure connection to the component to which you want to connect it. You can secure the wire in place by soldering it to your component hole or you can simply wrap a little bit of electrical tape around the loop for a quick, easy fix.

Quick Start Tips

You’ll find lots of good tips and tricks for making your first simple robots as you read through this chapter. Here are the most important things to remember:

   Make sure that your components are wired up securely.

   Watch out for loose ends, fraying wires, and untidy connections.

   Bare wire is conductive. If two bits of bare wire touch each other, you will cause a short circuit, so strip away only as much of the plastic coating as needed.

   Never strip wire that is connected to power. The power sources we use in this book are very small and cannot hurt you, but if you move on to experimenting with robotics that need more power, you should be very careful. Electricity, especially the electricity that comes out of the wall, can really hurt or even kill you.

Tools and Materials List

To make all the projects in this part, you’ll need the following tools:

   Wire strippers

   Wire cutter

   Hot glue gun or superglue

   Scissors

   Craft knife

   Wooden or metal skewer

You’ll also need the following materials:

From a Craft Store

   Googly eyes

   Strong craft wire

   Colored felt tip pens

   Ordinary and double-sided sticky tape

   Assorted colors of card

   Paper straw

   Glue stick

   Paper

From an Electronics Store

   Three 3V DC motors

   Three 3V battery packs with on/off switches

   Three batteries

   Stranded electrical wire

   Teknikio sewable light sensor

From Your Home

   Assorted trash, including three bottle corks

   Cardboard box