Video tutorials -

• Gears

This is a 10 out of 10 video tutorial for the FIRST LEGO League 2020 RePLAY robotics competition and the Treadmill mission. We build a robot with consistent behavior that is able to achieve the mission every time

Accuracy and consistency is the topic of this tutorial, as all 10 out of 10 tutorials are at FLLCasts. We use a robot build only from LEGO Mindstorms Robot Inventor parts and we accomplish the mission 10 out of 10 times. You will see how we use an active gear attachment to catch the wheel and pull it to the black circle, which accomplishes the mission

As we are already off the season we decided to look back at the competition. First, we will take a look at the working solution for FIRST LEGO League 2017 Manhole Cover. This was generally accepted as one of the most difficult missions during the competition. We've built a single attachment to accomplish it. 

(we are releasing the video without explanations and will add the explanations later)

The after season review continues. No. We are not publishing a single solution for the next season before it is over, but let's learn from the previous season. The current tutorial is about three missions at once on a single run with the robot. Most FIRST LEGO League teams try to accomplish one-two missions on a single run out of the base, and three is really what makes the difference

This video tutorial is part of the series on how to make your robot 100% precise and accurate. We accomplish the Emergency Walk mission 10 out of 10 times. The attachment works. Every time the attachment is started in successfully accomplishes the mission and this is one of the most difficult missions on FIRST LEGO League competitions ever. 

In this episode we build a reusable attachment for a LEGO Mindstorms EV3 robot that changes gears orientation and direction. It is one of the most useful attachments that you could use to move levers up/down and right/left. Adding the attachment on the robot takes 2-3 seconds and shows a very useful general principle of how to build reusable attachments.

This video tutorial focuses on accomplishing M8 Artificial Habitat of the FIRST LEGO League 2024-2025 SUBMERGED Challenge using the Nautiq box robot (a LEGO Education SPIKE Prime robot). The run uses a simple active pinless attachment mounted at the front of the robot for precise engagement with the mission model.

The goal is a perfect 10 out of 10 runs by positioning all four crabs upright with their yellow bases touching the mat. You can find the full explaining tutorial here.

This video tutorial focuses on accomplishing M8 Artificial Habitat of the FIRST LEGO League 2024-2025 SUBMERGED Challenge using the Nautiq box robot (a LEGO Education SPIKE Prime robot). The run uses a simple active pinless attachment mounted at the front of the robot, designed for precise engagement with the mission model.

The goal is to position all four crabs upright with their yellow bases touching the mat for maximum points, a task requiring careful alignment and controlled movements. While it is possible to complete the mission with fewer crabs upright, this run is programmed for the full score, using dedicated movement commands in a separate run for maximum accuracy. This approach combines a reliable mechanical design with precise navigation to meet the mission’s demanding scoring conditions.

This 10 out of 10 video tutorial focuses on the flawless accomplishment of M05 Angler Fish, M09 Unexpected Encounter, M10 Send over the Submersible, and M11 Sonar Discovery of the FIRST LEGO League 2024-2025 SUBMERGED Challenge using the Nautiq box robot.

The run uses a combination of aligning, front, and back attachments to execute multiple tasks in one run, including a rotation transfer system using a single long axle for M11, early execution of M10 for a strategic edge, and sensor-based alignment for precision. Despite the reduced per-run accuracy due to the mission count, this method ensures that when the run works, it secures an exceptionally high score.

This video tutorial focuses on accomplishing M05 Angler Fish, M09 Unexpected Encounter, M10 Send over the Submersible, and M11 Sonar Discovery of the FIRST LEGO League 2024-2025 SUBMERGED Challenge using the Nautiq box robot (a LEGO Education SPIKE Prime robot). The run uses three attachments in sequence: an aligning attachment at the start to reduce initial inaccuracies, a front attachment for solving M05 and M10 while collecting krill, reef segments, and the water sample, and a back attachment for solving M11, delivering the unknown creature for M09, and collecting plankton and seabed samples.

The front attachment is particularly interesting in this configuration because it integrates two color sensors and one motor directly onto the attachment itself. These sensors are used to align the robot to the black line near M10, while the aligning attachment at the start ensures a precise launch position.

This version of the big run takes on significantly more missions in a single attempt than a standard sequence, which naturally comes at the cost of reduced accuracy. In the current FLL competition format—where only your best score from three attempts is counted—this trade-off can be highly strategic. A run that works perfectly even just once can yield a massive point boost, making this kind of high-reward, lower-consistency approach a potential game-changer for teams willing to take the risk.

This video tutorial focuses on accomplishing M10 Send Over the Submersible of the FIRST LEGO League 2024-2025 SUBMERGED Challenge using the Nautiq box robot. In this series of test runs, the goal is to achieve 10 out of 10 successful deliveries where the submersible reaches the opposing field, and the robot disengages without touching the mission model at the match’s end.

The run uses a simple pinless attachment with stopping beams for consistent positioning, combined with programming that integrates a parallel timer for perfect match-end execution. This setup gives the robot the highest possible success rate for both mission requirements across repeated trials.

This video tutorial focuses on accomplishing M10 Send Over the Submersible of the FIRST LEGO League 2024-2025 SUBMERGED Challenge using the Nautiq box robot (a LEGO Education SPIKE Prime robot). The run uses a simple pinless attachment that engages with the front gearwheel of the robot to raise the yellow slider. Built-in stopping beams ensure the attachment always starts from the same position for consistent operation.

This minimalistic but reliable design allows the robot to perform the lift with stability and repeatability, making it well-suited for a time-sensitive mission. The attachment’s simplicity also enables quick setup between runs, keeping it competition-ready.

Based on feedback from many of you in this episode I would like to show you how to build an active attachment that changes the orientation of a gear wheel placed vertically to a gear wheel placed horizontally. This attachment could be used in competitions and shows a basic principle of changing the orientation. All attachments could follow the same principle. 

This video tutorial focuses on accomplishing M11 Sonar Discovery and M12 Feed the Whale of the FIRST LEGO League 2024-2025 SUBMERGED Challenge using the Nautiq box robot. The goal is to achieve 10 out of 10 successful completions, with the robot reliably rotating the sonar and feeding the whale in every trial.

The run uses a combined two-part attachment where the front section opens the whale’s mouth and drops the krill while the rear section uses a chain and hook mechanism to rotate the sonar. The programming ensures precise timing, correct hook positioning, and a small forward adjustment to avoid snagging, enabling consistent results across all attempts.

This video tutorial focuses on accomplishing M11 Sonar Discovery and M12 Feed the Whale of the FIRST LEGO League 2024-2025 SUBMERGED Challenge using the Nautiq box robot (a LEGO Education SPIKE Prime robot). The run uses a combined two-part attachment for maximum efficiency. The front section is designed to drop the krill into the Whale for M12, using a stationary beam to open the whale’s mouth and an angled beam to tip the krill container so they fall inside. Wheels are added as counterweights to prevent the container from opening during movement.

The rear section operates the sonar rotation for M11, using a chain-driven mechanism to transfer power from the robot to the mission model. A hooked beam is integrated at the end, allowing it to easily catch the yellow part of the sonar for rotation. This combined design allows the robot to complete both missions in one smooth, coordinated run without swapping attachments.

In this video lesson I am building a LEGO Mindstorms EV3 active attachment powered by a small gear wheel. The attachment could move up and down, it is very useful for collecting objects. It could easily be adapted and used on other robots.

We are making a parallel with Video Lesson 56 from the series and we are also showing ways to improve the stability of an axle which is most of the time neglected, but could lead to great problems.

This video tutorial focuses on accomplishing M01 Coral Nursery and M03 Coral Reef of the FIRST LEGO League 2024-2025 SUBMERGED Challenge using the Nautiq box robot (a LEGO Education SPIKE Prime robot). The aim is to see a consistent accomplishment by lifting the coral tree to the coral tree support and delivering reef segments outside the launch area in one smooth sequence.

The robot uses a motor-powered attachment to lift the coral tree precisely while a side holder secures the collected reef segments. This ensures both missions are completed without losing any pieces during movement. You can watch the full explaining tutorial here.

This video tutorial focuses on accomplishing M01 Coral Nursery and M03 Coral Reef of the FIRST LEGO League 2024-2025 SUBMERGED Challenge using the Nautiq box robot (a LEGO Education SPIKE Prime robot). The run uses a pinless motor-powered attachment specifically designed to raise the coral tree to the coral tree support while delivering reef segments outside the launch area. This attachment was chosen after testing multiple designs, and it proved to be one of the most reliable solutions for this task.

The motor-driven lifting mechanism is mounted using long axle pins due to the gearwheel’s position, and a heavy brick is added on top for extra sturdiness, preventing the attachment from popping off during operation. On the side, a simple holder secures the three reef segments collected in previous runs for easy delivery during this mission. This combination allows the robot to lift the coral tree smoothly, place it accurately, and complete the reef segment delivery in a single, well-coordinated sequence.

In this episode we continue from Episode 55 and we improve the durability and stability of the attachment for a LEGO Mindstorms EV3 robot. Many times attachments are not very stable which results in gaps between parts. The goal of the video is to give basic construction ideas.

Given the large number of gear wheels and axles in each EV3 and NXT sets there are many possibilities for building gear mechanisms. We are developing something like a gear box that has different axles that could all turn in different directions.

We are describing the Warm gear in this video. This worm gear does most of the magic of controlling how the different gear wheels move on the different axles. 

In this tutorial we would should you how to accomplish the FIRST LEGO League 2019-2020 Mission called Elevator. We are using the Whakatae - LEGO Education SPIKE Prime Competition Box robot

In this third video we show some of the tricks in building this Multi-axles mechanism. Things you could learn from an use in your next constructions. 

"What is the light in the room?" - should it even matter. You can use one program for all lighting conditions by calibrating the color/light sensor of the LEGO Mindstorms EV3/NXT robots.