Previously we caught the Truck with two rubber bands. The next step was to lift it. For lifting we used the Medium LEGO Mindstorms EV3 motors. In this video we are extending the attachment so that we could catch also the Ambulance. In forth video we would explore how to release both vehicles after transporting them.
Based on a request we are showing the robot construction with two rear motors instead of a differential. In this way, as a construction, it is closer to more students, but much more challеnging for programing.
We would look at the rules of the competition over our small model and we would start solving the field.
The robot works on the field and decodes the different colours that represent the rows and the columns.
In part one we build an attachment that uses a rubber band to solve a competition challenge. The rubber band was released with the use of a motor. In this video we are removing the dependency on the motor and you could use the motor for other missions.
We would continue from the previous program where we used variables and we would change this to arrays.
Building instructions for the Pinless Rubber Band Attachment:
Building instructions for the LEGO Mindstorms attachment using Rubber Bands
Building instructions for the LEGO Mindstorms robot attachment used at the FIRST LEGO League Natures Fury Competition. This robot attachment takes two of the building and moves them without demolishing them. It is a good example of the use of gear wheels and worm gear. The gear wheels move levers in opposite directions.
This third way of positioning the LEGO Mindstorms EV3 motors on the robot seems to be the most productive with the most advantages. We have named it "correct", but we completely understand there might be other even more efficient ways to position the motors on the robot.
Building instructions for a Robot Grabber used in the World Robotics Olympiad competition runs. The grabber is build with LEGO Mindstorms EV3. The base of the robot is available at /materials/69-wro-robot-2014-elementary
Kiril Mitov's most favourite attachment. To quote him "I had a really great fun building this attachment and recording the videos for it".
It's an attachment with a Rubber band and a Flywheel and a Gear Wheel and a Worm Gear. So much knowledge in just one small attachment. The goal of the attachment is to be able to have an active attachment without actually having a motor. So you can place that attachment and it will do the work for you instead of using a motor to power it.
Build with LEGO Mindstorms EV3 set.
When placing the rubber bands check out the tutorials
Placing the white rubber band is shown at https://www.fllcasts.com/tutorials/105-rubber-band-attachment-with-a-flywheel-solving-fll-2014-search-engine-part-2 at around 05:40.
Placing the red rubber band is shown at https://www.fllcasts.com/tutorials/104-rubber-band-attachment-with-a-flywheel-solving-fll-2014-search-engine-part-1
Let's try to integrate more of the things we have learned into a single attachment. One that could accumulate energy, conserve it and use it at the appropriate time. All this because of a Rubber Band and a Flywheel - and if you don't know what a flywheel is you should definitely watch this videos
The third part of the series the goal is to extend the robot attachment so that we could solve the second part of the FIRST LEGO League World Class mission challenge - to take the loop.
The attachment is now so advanced that we can do two tasks at once with it in order to solve the FIRST LEGO League 2014 World Class Search Engine Mission.
In the video we reach a conclusion. We have energy accumulated and to keep the system turning we need about 1J of energy each second to keep it turning.
Display a matrix with "life" and "dead" cells on the EV3 LEGO Mindstorms brick screen. The program is available. You can see it, change it, modify it and learn from it.
Calculate the number of rotations you have to do with the motor to rotate the final small 8 teeth driving gear wheel to 1.25 rotations?
What should you do as a teacher when the students are calculating the gear ratios and number of needed rotations?
The code is already ready. It is attached below the video. Let's see how the program works and what it does and how to use it.
