1. Lesson 1 - Moving forward


Today we will construct a simple robot that we will later program to move a specific distance. But before we start, let us get to know each other and get familiar with the way we carry out each class. It is expected of you to be kind and fair to your classmates throughout the course and follow the code of conduct.

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The robot we are about to build is a simple construction that has two front wheels, each driven by a single large motor and a third wheel in the back. The constructions we will build in the first few lessons are simpler in order to have enough time to learn how to program the robots to move around. 

Following instructions and building your robot

We will build the EasyBot quick robot and will explain how to follow building instructions.

In order to build the robot, you need to follow the instructions in the materials section.

How to follow a 3D material

On each step you will see a list of the required parts in the top left corner You will be given the length of the elements and the number of identical parts you will need.
In the middle of the screen you will see how to attach the parts one to another.

Sometimes there will be no parts shown in the top left corner. Then you will just have to turn the robot into a new position.
Usually, the first and the final step show the assembled robot.


Make sure that parts in your hands are always oriented in the same way as those on the page!

How to manage the image

Use the keyboard arrow keys to move to the next or previous step.
You can use the left mouse button to roll the construction so that you can examine it.
You can use the right mouse button to move the construction to the left or right.
You can use the scroll wheel to zoom out and zoom in the image.
Below the instructions you can find the "Autorotate", button which disables the automatic rotation of the camera. You can experiment when it is better to keep this option disabled or enabled. The default setting of the option is enabled.

Up until now, you haven't built a robot. And now you have to build your first robot with another person as well!

How to build a robot when working in pairs

Most probably you have not built a robot before. So not only you will build a robot for the first time, you will also have to work with another student. In order to make those first steps as smooth and pleasant as possible, we will point out some key things in the process of constructing a robot in pairs.

How to construct a robot in pairs

The robot should be constructed on the transparent lid of the box. The lid should be placed on your working desk, in front of the computer. That way the robot will be in a place convinient for both of you. Moreover, the lid will stop parts from falling on the floor or spreading over the whole desk.

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In order to be fair, you should take turns every few steps. One of you should construct and the other should pass him the necessary parts. It is best if you change your roles every 10 to 20 steps. Changing the roles every 5 steps will be too often while changing them in the middle of the instructions will be too far in time and the one passing the parts will get bored.

Tell your teacher which one of you will initially be Building and which one of you will be Passing parts.

Try not to compete with the other pairs in the room while constructing. Being fast is not important, only how precisely you follow the instructions so that you have successfully build your robot.

Precautions when building LEGO robots from PDF instructions

When you build from instructions there are a few things that you should be careful about.


Position of the brick

Pay attention to the position of the brick. The display should be looking toward you.
The display is important when choosing and starting programs, and the side of the ports is important in order to choose optimal cable length and route.

Pay attention to parts orientation

L-shaped beams could be mistakenly put in a mirrored position.
Pins could also be put on the left or on the right side of a beam, and that makes a difference.

Pay attention to the size of parts and their positioning

Pay attention to the length of parts - 7 axle vs 5 axle.
Also pay attention to the position of the pieces - which side of a pin goes to which hole on a beam.


In a nutshell

Always make sure that what you have built in each step looks exactly like the picture you see in the instructions.

Lego parts and their places in the box

Every part has its place in the box and you should return all parts to where they belong.

Where can I find "this part"?

You will build your robots much faster if you know the places of the parts in the box. In your boxes you will find a table for ordering the parts. Most sections have a description of the parts they contain:

  • Axles;
  • Double and triple pins;
  • Parts for changing the angle;
  • Slimmer parts;
  • Straight and angled beams.


Where should I leave this part?

You will have to disassemble your robot at the end of the lesson. You should return all parts to their sections. You cannot leave your robotics class before your teacher checked and approved the order of the box.


Upper part of the box

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Lower part of the box

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EasyBotEV3 - simplest

The very first robot that we usually build in a class. 

Now, after the robot is built, close the box so that it's out of your way and the desk is clear.

  1. Collect all parts from the desk and put them back in their places in the box.
  2. Close the box and move it to the side so it's not in your way.


It is time to start programming the robot. We will learn how to create a program, upload it to the robot and move the robot a given distance. Note that only really experienced programmers are able to create a program that works from the first time. It is totally okay to make a mistake and try again.

Common problems with motors not working

We will cover the typical reasons why your robot is not moving at all.

Wrong port

By default your motors must be connected to ports B and C. So if your robot is not moving, the first place you must look at is the ports. Do the cable connections correspond to the ports selected on the move block in the programming software?


Cable is not reliably connected

You must push the cable up until a "click" sound is heard. So, if the ports are correct, check the cable connections in the ports.

A way to demonstrate to someone that the cable is not reliably connected is to shake the robot and the cable will come out of the port.

Let’s change the program

How to change the program of the robot? And how to transfer the changes we are making to the robot’s behavior?

Make some changes

We already have a program for a forward movement.
But we want the robot to move further.


Let’s change the program

We already remember what we have to change – we have to increase the number of rotations.


Let’s run the robot

After we have made the change, it’s time to run the robot. Well, the robot does not move further enough yet! Why?


We have to load the changes to the robot!

It turns out that the computer and the robot do not communicate all the time. We have to connect the robot to the computer and load the program again in order to receive the changes and the new instructions.

Today's topic: Move a specific distance forward

Program the robot to move forward by 50cm (20 inches).

Your first program

There will be two lines on the floor – a start line and a finish line. The two lines should be 50 cm (20 inches) away from each other.

Make several attempts with your robot until you find the right settings for it to travel the required distance.

The idea is to experiment with the software. After you have made several attempts, we will show you our approach to the task.


Task: Travel a distance of precisely half a meter


  • The teacher has created one challenge field on the floor in the classroom:
    • He has marked a starting line on the floor.
    • There is a second line 50cm (20 inches) away from the first one.


The idea is to experiment with the software.

  1. Make multiple attempts with your robot in order to adjust the distance that it travels.
  2. The task is successful when the robot stops on the second line.

 On the line could mean the tires may not be touching the line, but when looked at from above, they seem to cross it.

Tasks to finish a class

  1. Take pictures and make videos of your robots
  2. Disassemble and arrange the robot
  3. Arrange your workplace
    • It is important to arrange the electronics of the robots on the cover of the box.
    • Wind up the programming cable so that it is assembled.
    • Put the robot cables next to the electronics.
    • Wind up the mouse cable around the mouse.
    • Wind up the cable of the laptop charger in a way that your teacher will show you.
    • When you turn off the computer, leave it next to the robot box.
  4. Turn off all programs on your computer
  5. Exit FLLCasts  
  6. Shut down your computer
  7. Put your chair under the desk.