FLL solving robot prototype 2

Model picture

Go to building instructions.

Building instructions

View the full parts list with links to BrickLink making it easy to find retailers selling the parts you need.

Parts list

Click to download the Mindstorms software for this model. You might have to readjust some variables in order to make the program work in your setup.

Download Program

Number of elements: 197.



Created October 27, 2017.




Created by Lasse Deleuran.

Create a BrickLink Parts list (XML format) for import into BrickLink wanted lists.

Go to the YouTube video for this model.

Go to the Rebrickable page for this model.

Click to download .mpd file to be open with LDraw tools such as MLCad and LDView.

Print building instructions.

About this model

Robot for solving the FLL Challenges, such as Hydro Dynamics in 2017/2018. This is the second prototype and the video shows how to solve Mission M13. See the full playlist here.

This version is an improvement over the first prototype in several ways:

  • The driving motors are turned so forward in the EV3 software translates into forward motion on the robot.
  • The footprint is smaller, making it easier to navigate on the mat.
  • The caster wheels have been replaced with bevel gears, resulting in more accurate driving when going straight.
  • The M-motor is now directly connected to the lifting mechanism which makes it easier to position and reset.
  • There are now two lifting sockets on the lower lifting assembly.
  • The color sensor is built into the robot base and is close to the center of the front of the robot, making it easy to program a line follower.

How to connect the motors and sensor

  • Port A: Front M-motor.
  • Port B: Left XL-motor.
  • Port C: Right XL-motor.
  • Port D: Front XL-motor.
  • Port 1: Color sensor.

How to build your own model

You can build your own copy once you have all the parts in the parts list.

This model is on and you can use their features to find out which parts you don't already have, as well as where to purchase them.

To see where to purchase all the parts, simply go to the rebrickable page for this model and use the functionality for either creating a wish list on BrickOwl, on BrickLink, or use the "Multi-Buy" feature which is able to search in both BrickOwl, BrickLink and independent stores.

If you already have LEGO sets and spare parts, then you can get an overview of the parts you need by creating an account on rebrickable and type in all the sets and spare parts you have available. Once you have done this you shoud go to the rebrickable page for this model and click the button. This will lead you to a page where you can see the additional parts you need. From here you can press the button to see where to purchase these parts.

Building instructions for this LEGO model

The building instructions are made by building the LEGO models in MLCad and generated in LDView using an old version of LPub. All this software is part of LDraw.


If you have any corrections or suggestions, please e-mail Lasse Deleuran at lassedeleuran@gmail.com.

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