Building a Robotic Arm | Grades Grade 6–Grade 12 | Classbox | Classbox

Building a Robotic Arm

Algorithms and ProgrammingElectrical EngineeringEngineering DesignStructures and Processes

Building a Robotic Arm

Grades Grade 6–Grade 12

9 × 45 min(6 hr 25 min total)

24 steps

Groups of 5

High School — Number and QuantityHigh School — Geometry

Standards Alignment

3 Standards Aligned

Create an account to view the education standards aligned to this lesson, filtered to your state.

Already have an account? Log in

Lesson Steps

1

Exploring the World of Robotics

25 min

<style type="text/css">.container
{
border-radius: 8px;
padding: 20px;
background-color: #E8F6FE;
text-align: left;
}

.infobox
{
display: flex;
}

.leftside
{
border-top-left-radius: 10px;
border-bottom-left-radius: 10px;
flex: 1;
padding: 20px;
}

.rightside
{
border-top-right-radius: 10px;
border-bottom-right-radius: 10px;
flex: 1;
padding: 20px;
}

.attention
{
border-radius: 10px;
padding: 20px;
background-color: rgb(219, 255, 215);
text-align: left;
}

.warning
{
border-radius: 10px;
padding: 20px;
background-color: rgb(255, 193, 199);
text-align: left;
}
</style>
<h2>Overview</h2>

<p> </p>

<p>Welcome to robotics! In this unit, you will embark on an exciting journey into the world of robotics! You will build your own robotic arm, learn different control paradigms, and program it to accomplish various challenges. You will get hands-on experience with coding and other cutting-edge technologies as they explore the potential of robotics</p>

<p> </p>

<hr />
<h2>Introduction to Robots</h2>

<p> </p>

<div class="container">
<p>So - let’s start with the basics. Ask yourself a few questions:</p>

<p> </p>

<ul>
<li>How can you tell if a machine is a robot?</li>
<li>What do we expect from a robot?</li>
</ul>

<p> </p>

<p>Reflect on these questions. Then watch the video below to help you understand the difference between robots and other kinds of machines.</p>

<p> </p>

<video controls="" height="auto" width="100%"><source src="https://www.dropbox.com/scl/fi/ctvgy0kmrz9zbxdqmvvog/Bot-or-Not.mp4?rlkey=u451fuhkv79fulr87o41dnuaw&e=1&st=t3w2rp66&raw=1" type="video/mp4" /></video>

<p> </p>

<p>A robot is different from a remote controlled machine through its autonomous capabilities and advanced programming. Autonomous means it can make its own decisions. While both robots and remote-control machines can perform tasks, a robot possesses the ability to make decisions and carry out actions without constant human direction.</p>

<p>A robot is designed to understand its environment through sensors, process information, and do complex tasks based on its programming.</p>

<p>This autonomy allows robots to adapt to changing situations, learn from experience, interact with their surroundings, and do meaningful things in the physical world. This is more sophisticated than a remote-controlled machine, which relies solely on external human commands for operation.</p>
</div>

<p> </p>

<hr />
<h2>Bot or Not</h2>

<p> </p>

<div class="container">
<p>Think about the definition of a robot. With that in mind, take a look at these videos and consider whether or not you would call each of these devices a robot.</p>

<p> </p>

<table style="margin: auto;">
<colgroup>
<col style="width:50%" />
<col style="width:50%" />
</colgroup>
<thead>
<tr>
<td style="text-align: center; padding: 5px;"><strong>Battlebots</strong></td>
<td style="text-align: center; padding: 5px;"><strong>Ascender Vacuum Cleaner</strong></td>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: center; padding: 5px;">
<div style="padding:62.5% 0 0 0;position:relative;"><iframe allow="autoplay; fullscreen; picture-in-picture" allowfullscreen="" frameborder="0" src="https://www.youtube.com/embed/0Q7nZlcOlkg?si=qB-CyJhsnWwSIhQ6" style="position:absolute;top:0;left:0;width:90%;height:90%;" title="lskdfjsldkfj"></iframe></div>
</td>
<td style="text-align: center; padding: 5px;">
<div style="padding:62.5% 0 0 0;position:relative;"><iframe allow="autoplay; fullscreen; picture-in-picture" allowfullscreen="" frameborder="0" src="https://www.youtube.com/embed/m6z5vhscebw?si=lONL1KDyaQ60wVZR" style="position:absolute;top:0;left:0;width:90%;height:90%;" title="lskdfjsldkfj"></iframe></div>
</td>
</tr>
<tr>
<td style="text-align: center; padding: 5px;"><strong>DJI Mavic Drone</strong></td>
<td style="text-align: center; padding: 5px;"><strong>Tesla in Full Self-Driving Mode</strong></td>
</tr>
<tr>
<td style="text-align: center; padding: 5px;">
<div style="padding:62.5% 0 0 0;position:relative;"><iframe allow="autoplay; fullscreen; picture-in-picture" allowfullscreen="" frameborder="0" src="https://www.youtube.com/embed/0YnfCSiCBQE?si=p4bJwpt0uneJGNP-" style="position:absolute;top:0;left:0;width:90%;height:90%;" title="lskdfjsldkfj"></iframe></div>
</td>
<td style="text-align: center; padding: 5px;">
<div style="padding:62.5% 0 0 0;position:relative;"><iframe allow="autoplay; fullscreen; picture-in-picture" allowfullscreen="" frameborder="0" src="https://www.youtube.com/embed/tlThdr3O5Qo?si=mc6RgUVCKhDM5RSK" style="position:absolute;top:0;left:0;width:90%;height:90%;" title="lskdfjsldkfj"></iframe></div>
</td>
</tr>
</tbody>
</table>
</div>

<p> </p>

<hr />
<h2>Assessment</h2>

<p> </p>

<div class="container">
<p>Let's take a look at how these devices match up with our criteria for defining a robot</p>

<p> </p>

<table cellpadding="6" cellspacing="1" style="width: 90%; margin: auto; border-collapse: collapse; border: 1px solid;">
<colgroup>
<col style="width:25%;" />
<col style="width:18.75%;" />
<col style="width:18.75%;" />
<col style="width:18.75%;" />
<col style="width:18.75%;" />
</colgroup>
<thead>
<tr>
<td style="background-color: rgb(232, 246, 254); border: 1px solid;"> </td>
<td style="background-color: rgb(232, 246, 254); border: 1px solid;"><strong>BattleBots</strong></td>
<td style="background-color: rgb(232, 246, 254); border: 1px solid;"><strong>Vacuum</strong></td>
<td style="background-color: rgb(232, 246, 254); border: 1px solid;"><strong>Drone</strong></td>
<td style="background-color: rgb(232, 246, 254); border: 1px solid;"><strong>Tesla</strong></td>
</tr>
</thead>
<tbody>
<tr>
<td style="background-color: rgb(232, 246, 254); border: 1px solid;"><strong>Self Controled?</strong></td>
<td style="background-color: rgb(232, 246, 254); border: 1px solid;">NO</td>
<td style="background-color: rgb(232, 246, 254); border: 1px solid;">YES</td>
<td style="background-color: rgb(232, 246, 254); border: 1px solid;">NO</td>
<td style="background-color: rgb(232, 246, 254); border: 1px solid;">YES</td>
</tr>
<tr>
<td style="background-color: rgb(232, 246, 254); border: 1px solid;"><strong>Intelligence?</strong></td>
<td style="background-color: rgb(232, 246, 254); border: 1px solid;">NO</td>
<td style="background-color: rgb(232, 246, 254); border: 1px solid;">YES</td>
<td style="background-color: rgb(232, 246, 254); border: 1px solid;">NO</td>
<td style="background-color: rgb(232, 246, 254); border: 1px solid;">YES</td>
</tr>
<tr>
<td style="background-color: rgb(232, 246, 254); border: 1px solid;"><strong>Sensors?</strong></td>
<td style="background-color: rgb(232, 246, 254); border: 1px solid;">NO</td>
<td style="background-color: rgb(232, 246, 254); border: 1px solid;">YES</td>
<td style="background-color: rgb(232, 246, 254); border: 1px solid;">YES</td>
<td style="background-color: rgb(232, 246, 254); border: 1px solid;">YES</td>
</tr>
<tr>
<td style="background-color: rgb(232, 246, 254); border: 1px solid;"><strong>Complex Tasks?</strong></td>
<td style="background-color: rgb(232, 246, 254); border: 1px solid;">YES</td>
<td style="background-color: rgb(232, 246, 254); border: 1px solid;">YES</td>
<td style="background-color: rgb(232, 246, 254); border: 1px solid;">YES</td>
<td style="background-color: rgb(232, 246, 254); border: 1px solid;">YES</td>
</tr>
<tr>
<td style="border: 1px solid;"><strong> Bot or Not?</strong></td>
<td style="background-color: rgb(255, 193, 199); border: 1px solid;">NO</td>
<td style="background-color: rgb(219, 255, 215); border: 1px solid;">YES</td>
<td style="background-color: rgb(255, 193, 199); border: 1px solid;">NO</td>
<td style="background-color: rgb(219, 255, 215); border: 1px solid;">YES</td>
</tr>
</tbody>
</table>

<p> </p>

<p>Some of these devices are very close to something we might consider a robot, yet they do not meet every criteria as they were shown in the videos:</p>

<p> </p>

<ul>
<li><strong>BattleBots</strong>: This video shows several humans controlling the Warhead, which is the point. These machines are technically not robots.</li>
<li><strong>Ascender Vacuum Cleaner</strong>: These machines are robots.</li>
<li><strong>DJI Mavic Drone</strong>: If controlled by human input, drones are not robots. If they fly autonomously, they are robots.</li>
<li><strong>Tesla</strong>: A Tesla in full self-driving mode is a robot. If the human takes control, it is no longer a robot.</li>
</ul>
</div>

<p> </p>

<hr />
<h2>Learning Objectives</h2>

<p> </p>

<div class="container">
<p>Because robots are used in many different fields such as medicine, manufacturing, logistics and security, these skills can prepare you for many potential careers. These videos will show you just a few examples of fields where robots are important. Click to watch each of them.</p>

<p> </p>

<table>
<colgroup>
<col style="width:50%" />
<col style="width:50%" />
</colgroup>
<thead>
<tr>
<td style="text-align: center;"><strong>Factory Automation (Fanuc palletizing robot)</strong></td>
<td style="text-align: center;"><strong>Logistics/Warehouse (SQUID warehouse automation robot)</strong></td>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: center;">
<div style="padding:62.5% 0 0 0;position:relative;"><iframe allow="autoplay; fullscreen; picture-in-picture" allowfullscreen="" frameborder="0" src="https://www.youtube.com/embed/xvZ2nGJP1PA?si=qtmVBpRTpQMqLquO" style="position:absolute;top:0;left:0;width:90%;height:90%;" title="lskdfjsldkfj"></iframe></div>
</td>
<td style="text-align: center;">
<div style="padding:62.5% 0 0 0;position:relative;"><iframe allow="autoplay; fullscreen; picture-in-picture" allowfullscreen="" frameborder="0" src="https://www.youtube.com/embed/l63CxPa-DYk?si=DFUC221C4Sht4205" style="position:absolute;top:0;left:0;width:90%;height:90%;" title="lskdfjsldkfj"></iframe></div>
</td>
</tr>
<tr>
<td style="text-align: center;"><strong>Food Preparation (ABB Robotics delta robots)</strong></td>
<td style="text-align: center;"><strong>Agriculture (Multiple companies)</strong></td>
</tr>
<tr>
<td>
<div style="padding:62.5% 0 0 0;position:relative;"><iframe allow="autoplay; fullscreen; picture-in-picture" allowfullscreen="" frameborder="0" src="https://www.youtube.com/embed/aPTd8XDZOEk?si=kzkdjK3osKEB3O7q" style="position:absolute;top:0;left:0;width:90%;height:90%;" title="lskdfjsldkfj"></iframe></div>
</td>
<td>
<div style="padding:62.5% 0 0 0;position:relative;"><iframe allow="autoplay; fullscreen; picture-in-picture" allowfullscreen="" frameborder="0" src="https://www.youtube.com/embed/4qrlFse5I1U?si=Zh-m7vscJ26mgN-F" style="position:absolute;top:0;left:0;width:90%;height:90%;" title="lskdfjsldkfj"></iframe></div>
</td>
</tr>
</tbody>
</table>

<p> </p>

<p>In this Classbox you will build your own robotic arm and program it by using different control methods. Get ready to unleash your creativity and learn assembly techniques, circuit building and programming skills along the way. Below you can see what you will be able to do in this course - these learning objectives will become clearer as you work through the unit:</p>

<ul>
<li>Given a set of materials and instructions, you will be able to assemble a 3DoF (3 Degrees of Freedom) robotic arm that meets the specified design criteria.</li>
</ul>

<ul>
<li>Given a set of increasingly sophisticated control methods, you will be able to apply them to achieve certain challenges.</li>
</ul>

<ul>
<li>Given a set of performance criteria and constraints (the challenges), you will be able to program the robotic arm to operate and accomplish a wide range of tasks.</li>
</ul>

<p>In addition to achieving the learning objectives, this course will also provide you with opportunities to develop and build important durable and technical skills. You can apply these skills in many different careers. For example: robot operator, robot programmer, installation/maintenance technician, robotics engineer, or system integrator. Below are some of the key skills you will develop from completing this project:</p>

<p> </p>

<div class="infobox">
<div class="leftside" style="background: #A4C2F4;">
<p><strong>Durable Skills</strong></p>

<ul>
<li><strong>Critical thinking:</strong> You can analyze robotic arm performance characteristics in each control paradigm, identify patterns, and use this information to improve the robot’s performance.</li>
</ul>

<ul>
<li>
<p><strong>Adaptability:</strong> You can adapt to challenges and changes in the project, such as unexpected technical issues or design flaws. They can also adapt to working with different team members and adjust their approach accordingly.</p>
</li>
</ul>

<ul>
<li>
<p><strong>Learn how to learn:</strong> You can learn how to break down large, complex challenges into smaller, more approachable tasks that can be solved one at a time — enabling a solution to the large complex challenge.</p>
</li>
</ul>
</div>

<div class="rightside" style="background-color: #FFE599;">
<p><strong>Technical Skills</strong></p>

<ul>
<li><strong>Mechanical assembly:</strong> You will learn how to assemble the linkages and joints in the robot so that it functions well, while learning how to successfully apply mechanical tools and fasteners.</li>
</ul>

<ul>
<li>
<p><strong>Circuit building:</strong> You will learn how to build circuits and use microcontrollers, potentiometers, motors, and other electronics to construct and control the robotic arm.</p>
</li>
</ul>

<ul>
<li>
<p><strong>Programming:</strong> You will learn how to enable autonomous actions by programming the robot using the Arduino Integrated Development Environment (IDE) and a scripting language to create robotic path programs.</p>
</li>
</ul>

<ul>
<li>
<p><strong>Robotics:</strong> You will learn the principles of mechatronics and how to integrate different systems to build a functional robotic arm like those used in industry.</p>
</li>
</ul>
</div>
</div>

<p> </p>

<p>In any technical undertaking, there are three aspects common to all successful implementations. If you want to succeed, it is very important that you know the right methods to use in each situation (<strong>What</strong>), apply the right technique to each method (<strong>How</strong>), and execute all methods in the right order (<strong>When</strong>).</p>

<p>A more simple way of saying this: You need to know what to do, how to do it, and when to do it.</p>

<p>The method for assembling each type of joint has its own dedicated technique that makes it quick and easy to put together, but difficult if you don’t know what to do. You must apply these techniques when instructed and be careful to execute each step of the building process in the correct order - otherwise you may have to take apart much of what you have already built in order to assemble a later step.</p>
</div>

<p> </p>

<hr />
<h2>About the Robotic Arm Classbox</h2>

<p> </p>

<div class="container">
<p>Let’s open your Betabox Robotic Arm kit! It has everything you need to build an awesome Robotic Arm.</p>

<p> </p>

<p> </p>

<p>Let’s start with the parts that will become the robot itself. Most parts are acrylic, sometimes called by the brand name Plexiglas. Your robot may be a different color acrylic. Don’t worry. They are all built the same way.</p>

<p> </p>

<p> </p>

<p>We pre-mounted servo motors on several of the components. And we included a bag of hardware, with extras in case you lose one or two.</p>

<p> </p>

<div class="infobox">
<div class="warning">
<p><strong>WARNING!</strong></p>

<p>On these preassembled servo components, <strong>DO NOT TURN THE ATTACHED PARTS UNLESS OR UNTIL THE INSTRUCTIONS TELL YOU TO DO SO</strong>. </p>

<p>You might break or damage the servos if you turn the parts too far.  Leave the parts in the orientations shown in the image below until you are instructed to adjust the part positions.</p>

<p> </p>

<div style="text-align: center;"></div>
</div>
</div>

<p> </p>

<p>Your kit also includes electronics to control the robot arm. You will find an ESP32 microcontroller and breakout board, a breadboard, an AC-to-DC adapter, potentiometers, various small electronics components, and a PS4 Gamepad controller.</p>

<p> </p>

<p> </p>

<p>Although we don’t need it yet, we’ll be using the PS4 controller soon.  To be ready, make sure your controller is fully charged. There is a charger cable in the box with the PS4. You’ll need to plug it into a USB A port, like the one on your computer, or a standard 5VDC phone charger.</p>

<p> </p>

<div class="infobox">
<div class="leftside" style="background: #A4C2F4;">
<h5><strong>Planning Ahead:  Prepare the PS4 Controller for Future Use</strong></h5>

<p>Plug the other end into the charging port of the controller, which is a USB Micro-B connector.</p>
</div>

<div class="rightside" style="background-color: #FFE599;"></div>
</div>

<p> </p>

<div class="attention">
<p><strong>ATTENTION!</strong> </p>

<p>It may take up to two hours to fully charge the battery. While the battery is charging, the front LED (the “light bar”) will slowly blink orange. When charging is complete, the light bar will turn off. Don’t leave the charger plugged in longer than necessary.</p>
</div>

<p> </p>

<p>Your kit also includes the handy WorkBench Base and Integrated Organizer (IO) from Phase Dock - it will keep all the small parts easy to find and safe while you build the robot arm. Finally, inside this workbench you will find some tools, a pencil, and some foam blocks that you can use to complete the challenges.</p>

<p> </p>

<p> </p>

<p> </p>
</div>

<p> </p>

<hr />
<h2>Video Walkthrough</h2>

<p> </p>

<div class="container">
<div style="padding:56.25% 0 0 0;position:relative;"><iframe allow="autoplay; fullscreen; picture-in-picture; clipboard-write" frameborder="0" src="https://player.vimeo.com/video/986826839?badge=0&autopause=0&player_id=0&app_id=58479" style="position:absolute;top:0;left:0;width:100%;height:100%;" title="01_Robot_Arm_What's In the Kit_v1"></iframe></div>
</div>

2

Safety

30 min

<style type="text/css">.container
{
border-radius: 8px;
padding: 20px;
background-color: #E8F6FE;
text-align: left;
}

.infobox
{
display: flex;
}

.leftside
{
border-top-left-radius: 10px;
border-bottom-left-radius: 10px;
flex: 1;
padding: 20px;
}

.rightside
{
border-top-right-radius: 10px;
border-bottom-right-radius: 10px;
flex: 1;
padding: 20px;
}

.description-boxes
{
display: flex;
flex-wrap: wrap;
gap: 2%;
}

.description-box
{
display: flex;
flex-wrap: wrap;
padding: 20px;
border-radius: 10px;
width: 32%;
}

.warning
{
border-radius: 10px;
padding: 20px;
background-color: rgb(255, 193, 199);
text-align: left;
}

.guidelines
{
padding: 20px;
border-radius: 10px;
background-color: #A4C2F4;
margin: 10px;
}

.guidelines img
{
margin-top: 1em;
}

iframe {
aspect-ratio: 16 / 9;
height: auto;
width: 100%;
}
</style>
<h2>Overview</h2>

<p> </p>

<p>In this section, you will learn how to protect yourself and your projects from injury or damage as you work with electricity and electronics. You will understand why electricity can be dangerous to humans, identify ways to avoid electrical damage, and describe methods to keep you, your workspace, and your project safe.</p>

<p> </p>

<hr />
<h2>Protecting Yourself and Your Work</h2>

<p> </p>

<div class="container">
<p>You may be asking yourself, "Just how is electricity dangerous?" To answer this question, we need to understand two aspects of electricity: the “pressure” pushing it through a wire, measured as voltage, and the amount of electricity that's being pushed through that wire, measured as amperage.</p>

<p>For you to get an electrical shock, you have to touch an exposed wire that has electrons being pushed through it by some force, measured in volts. Higher pressure is measured as higher voltage. Your skin does a great job of protecting you from this pressure (voltage)—but only up to a point. Once you cross a certain threshold—about 50 volts—the electrons can begin to penetrate your skin. That number gets lower if your skin is wet, and a lot lower if your skin is broken or cut. When this happens, you start to feel the painful sensation of an electric shock.</p>

<p>Now it gets dangerous because it’s not the voltage that kills you—it’s the amount of electricity flowing through your body (measured in amps) once the voltage opens the door. Even moderately high currents—as little as one amp—can burn you or stop your heart. How much current can flow from a wall outlet? Fifteen or twenty amps—and 120 volts can penetrate your dry skin.</p>

<p>That’s why we have created a safe learning environment that has low-voltage/low-current devices so you can experiment to your heart’s content without hurting yourself or someone else. You can still damage the electronic components you’ll use in this class, and even your computer under some circumstances, if you’re not careful. But it's very unlikely that you'll hurt yourself if you follow our precautions. So please pay close attention to this section; review safety practices often; and whatever you do, DON’T experiment with anything directly powered by a wall outlet. Always power your projects with a battery or a low-voltage transformer.</p>
</div>

<p> </p>

<hr />
<h2>Avoid Ruining Your Kit!</h2>

<p> </p>

<div class="container">
<p>As you know by now, power from a wall outlet can be very dangerous!</p>

<p>In these courses, we will never use wall outlets directly for power. When we do plug into the wall, we use <strong>transformers</strong> that convert <strong>high-voltage alternating current</strong> into the <strong>low-voltage direct current</strong> that your components are designed for, at a level that is safe for you.</p>

<p>You still need to be careful and <strong>pay close attention to the details</strong>. Even with low-voltage current, you can burn up the electronic components in your kit before you know what went wrong.</p>

<p> </p>

<div class="warning">
<div class="infobox">
<div class="leftside">
<p><strong>Review these guidelines to avoid burning the electrical components of your kit.</strong></p>

<p><b>NEVER</b> work on a circuit while power is applied. That means any kind of power, including batteries, and plugging your project into your laptop. Disconnect your USB cable from your computer before changing anything in your circuit.</p>

<p><strong>Do not</strong> connect power to a circuit until the circuit is finished and you have carefully checked your work.</p>
</div>

<div class="rightside">
<p></p>
</div>
</div>
</div>

<p> </p>

<p>If you smell anything burning, <strong>immediately disconnect the power</strong> and examine your circuit to find out what went wrong. Be careful how you handle and connect batteries—especially rechargeable lithium-ion batteries. Batteries store energy, and the chemistry they use can be flammable. If you connect the two ends of a battery together, known as a <strong>short circuit</strong>, you can start an explosive fire that is very difficult to put out.</p>
</div>

<p> </p>

<hr />
<h2>Keep Your Workspace Safe</h2>

<p> </p>

<div class="container">
<p>Keeping you and your workspace safe is the top priority. Review the following guidelines to ensure your safety while you have fun with your breadboard:</p>

<p> </p>
</div>

<p> </p>

<hr />
<h2>Keep Your Components Safe</h2>

<p> </p>

<div class="container">
<p>While most of the components you use are not too expensive, some are. As you advance in your work with electronics, components can become very expensive—hundreds of dollars each. Microcontrollers start at about $7 and can cost $100 or more. Even on the low end, if you fry several microcontrollers in a row, we may have to ask you to take out a loan to chip in for that.</p>

<p>Frying an electronic component (letting the magic smoke out of it) is almost always a sad thing. How does it happen? There are several ways:</p>

<p> </p>

<div class="description-boxes">
<div class="description-box" style="background: #A4C2F4;">
<p> </p>

<p>Applying too much voltage to any component is a sure way to smoke it. Almost everything you will be using has a maximum rated voltage, and it’s your job to make sure that is never exceeded.</p>
</div>

<div class="description-box" style="background: #FFE599;">
<p> </p>

<p>Common voltages in our projects are 12V, 5V and 3.3V. There is not much difference between 5V and 3.3V, but you will quickly fry a newer generation 3.3V microcontroller if you put 5V into one of the pins.</p>
</div>

<div class="description-box" style="background: #A4C2F4;">
<p> </p>

<p>In some cases, applying the voltage but not providing current (measured in amps) will damage your components as well. Motors are a good example - they need enough electricity flowing through them to do their job. If they don’t get that, they won’t perform well, and may actually get hot and slowly die.</p>
</div>
</div>

<p> </p>

<p>Some electronic components that use direct current are sensitive to the direction of the flow of electricity through them. They will only work with the electricity going in one direction. In extreme cases, they will die if the current is reversed. We say that these components have "polarity"</p>

<p>LEDs are a good example of a component with polarity. If you plug an LED into the breadboard backward, it will not light up. You might think it has burned out without realizing that it was just installed backward. The LED will not die; it just will not light up. So how can you tell which way to plug in an LED? Look closely at a new LED where the legs (called "leads") have not been bent and are still parallel. One lead is longer than the other.</p>

<p> </p>

<p> </p>

<p>That is not an accident. The longer leg is the POSITIVE lead; that wire always needs to be inserted into the breadboard TOWARDS THE DIRECTION THAT POWER IS COMING FROM. In a circuit by itself, we would connect the long lead to the red wire and the short lead to the black wire.</p>

<p>In this Fritzing diagram, you would insert the long leg of the LED in line with the resistor and the short leg of the LED into the GROUND power column. Because the LED is not large enough to reach that far, we use a short black jumper wire to connect the short leg of the LED to the ground/neutral column on the far side of the breadboard.</p>

<p> </p>
</div>

<p> </p>

<hr />
<h2>Keeping Electricity "In Bounds"</h2>

<p> </p>

<div class="container">
<p>A key concept in working with electricity is knowing how to keep it “in bounds.” Most materials fall into one of two categories: they either conduct electricity or they don’t. If they do, we call them conductors; if they don’t, we call them insulators. Conductors are almost always wrapped in insulators to keep the electricity from leaking out to anything that could be damaged—like you.</p>

<p>Then, making sure that there is good insulation everywhere it needs to be is a key strategy in keeping you and your electronic components safe. Click each topic below to review the following safety guidelines!</p>

<p> </p>

<details class="guidelines"><summary><strong>Bare Wires</strong></summary>
<p>The single most important thing is to keep bare wires in different parts of your circuit from touching each other. Pay very close attention to any wire that is not covered in insulation. The bare part of the wire should never touch another uninsulated component that it is not supposed to be connected to. Double-check this before powering up your circuit each time.</p>
</details>

<details class="guidelines"><summary><strong>Insulated Wires</strong></summary>

<p></p>

<p>Don’t use uninsulated wires where they may touch other energized wires or components. Always use insulated wires when possible.</p>
</details>

<details class="guidelines"><summary><strong>Tool Inspection</strong></summary>
<p>Small cracks in the insulation on the handle of a tool, wire, or anything else can cause a nasty shock - or worse. Inspect your tools and equipment regularly.</p>
</details>

<details class="guidelines"><summary><strong>Resistors</strong></summary>
<p>Use the proper resistor for your project. If a resistor is forced to dissipate too much power, it gets hot. Sometimes, it simply causes your project to fail. In worse cases, the resistor may cause materials around it (like the PCB) to catch fire.</p>
</details>

<details class="guidelines"><summary><strong>Wire Treatment</strong></summary>
<p>Pulling on jumpers by the wires, instead of by the black plastic ends can break the connection and spoil your project. This is very difficult to troubleshoot, so treat your wires with care.</p>
</details>

<details class="guidelines"><summary><strong>Wire Thickness</strong></summary>
<p>Also use the proper gauge (thickness) wire. Heavier wires can carry more current. Wires and power cords that are undersized can heat up and cause trouble. When in doubt, build it stout! Use the next larger gauge if you have any concerns that the wire you are using is too small. That will not be a problem in this course, but you should know about this rule as you move on to larger and more challenging projects.</p>
</details>

<details class="guidelines"><summary><strong>Maximum Voltage</strong></summary>
<p>Tools such as multimeters have a maximum voltage rating. Know it and pay attention to it. People get electrocuted by using a meter beyond its voltage capability.</p>
</details>
</div>

<p> </p>

<hr />
<h2>Avoiding Battery Fires</h2>

<p> </p>

<div class="container">
<p>Finally, let’s circle back to lithium-ion batteries, which are another potential fire hazard just by themselves. The hazard occurs when the material in the battery becomes extremely hot and causes a fire and/or an explosion. This usually happens in one of two ways:</p>

<p> </p>

<div class="infobox">
<div class="leftside">
<ul>
<li>As the battery is being charged, the control circuitry may fail. If that happens, the charger will keep pumping more electricity into a battery that’s already full, and eventually, it gets hot enough to burn.</li>
<li>An even faster way to start a battery fire is to short-circuit a battery to itself or connect two batteries in a loop (positive on one battery to negative on the other). The batteries start to feed each other, get hot, and explode.</li>
</ul>
</div>

<div class="rightside"></div>
</div>

<p> </p>

<p>Lithium-ion battery fires are extremely dangerous because they can start by exploding, which sends shrapnel and burning chemicals everywhere—like into your eyes—and once started, they are hard to put out. Sometimes they have to burn themselves out. If the battery is close to you or in your pocket, that can be very bad.</p>

<p>Houses and cars have caught fire and people have been severely burned. Quality batteries have safety mechanisms – such as temperature monitoring – built into them to help prevent problems. If you buy batteries, look for these features.</p>

<p>Bottom line: Don't charge batteries unattended. Pay very close attention to polarity. Watch this video to see how a battery can easily explode:</p>

<p> </p>
<iframe allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" allowfullscreen="" frameborder="0" height="315" referrerpolicy="strict-origin-when-cross-origin" src="https://www.youtube.com/embed/oieH2wwDGzo?si=X2A9-Nnt4ip3dhY5" style="width:100%;" title="YouTube video player" width="560"></iframe>

<ul>
<li>Recall why electricity can be dangerous to humans</li>
<li>Identify ways to avoid electrical and battery damage</li>
<li>Describe methods to keep you, your workspace, and your project safe</li>
</ul>

<p>Much of the information you have covered in this section considers circuits far more dangerous and powerful than what you will interact with - however, it is still important to have a broad understanding of electrical safety, as it will apply to the work you do with your robotic arm just the same.</p>
</div>

3

Preparing Your Robotic Arm to Build

10 min

<style type="text/css">div.parts
{
background-color:#E8F6FE;
border-radius: 8px;
padding: 20px;
}
div.parts img
{
display: block;
margin: auto;
}
div.steps
{
background-color:#E8F6FE;
border-radius: 8px;
padding: 20px;
}
div.steps img
{
margin: auto;
display: block;
}
</style>
<h2>Overview</h2>

<p> </p>

<p>In this section, you will learn about various tools in your kit and prepare your robotic arm for assembly! This includes learning about two different types of screws and how to prep your robotic arm's plates if needed.</p>

<p> </p>

<hr />
<h2>The Tools</h2>

<p> </p>

<div class="parts">
<p>Find the following tools and hardware:</p>

<p> </p>

<ul>
<li>Screwdriver</li>
<li>Paper Plate</li>
<li>Black Multi-Tool</li>
<li>Hardware Bag</li>
</ul>

<p> </p>

<p>▼ Figure 3.1.1</p>

<p></p>
</div>

<p> </p>

<hr />
<h2>Preparing the Plates</h2>

<p> </p>

<div class="steps">
<p>Take a closer look at the plates for your robotic arm:</p>

<p> </p>

<ul>
<li>If you are the first person to use this kit, there may be paper backing on some of the parts.
<ul>
<li>If there is, use the scraper point of the MultiTool to remove the paper. The paper protects the acrylic while it is being manufactured and keeping it on can add unneeded friction to your robotic arm. Refer to the video below if you need help using the scraper.</li>
</ul>
</li>
</ul>

<p>If the parts do not have paper backing, yay! You can skip this step.</p>
</div>

<p> </p>

<hr />
<h2>Nuts and Screws</h2>

<p> </p>

<div class="steps">
<p>Take a closer look at the nuts and screws that you have in your bag:</p>

<p> </p>

<ul>
<li> Notice that you have three different lengths of screw.
<ul>
<li>You should use the screw gauge on your mult-tool before using any screw to confirm that it is the correct length.
<ul>
<li>Refer to Figure 3.1.3 below to see the different screws.</li>
</ul>
</li>
</ul>
</li>
<li>Notice that you have two different types of nuts
<ul>
<li>The flat nuts are standard hex nuts.</li>
<li>The ridged nuts are Nyloc nuts that are thicker and have a nylon ring on one side.</li>
<li>Refer to Figure 3.1.4 below and notice the difference between the two nuts.</li>
</ul>
</li>
</ul>

<p> </p>

<p>▼ Figure 3.1.3</p>

<p></p>

<p> </p>

<p>▼ Figure 3.1.4</p>

<p></p>
</div>