The attachment builds on previous episodes this time using two LEGO rubber bands. When a lever is released the rubber band exerts pressure on it and moves it in a circular motion. As an example we are solving the 2012 FIRST LEGO League, Senior Solutions, stove mission (which was quite interesting as a mission)
- 19 Jul 2015
The FIRST LEGO League 2012, Senior Solutions, Oven mission involved a circular motion. Teams had to build attachments that could move the Oven lever in half a circle. Now this proved to be challenging to do without the use of a motor. It is always a good idea to do every possible mission without a motor because you could save the motor for missions where it is actually not possible to accomplish without them.
Having said that, rubber bands for this mission is a very elegant solution.
Check out the video and leave a comment if you have any questions or suggestions for new videos.
Previous videos on rubber bands:
- Rubber bands - Solving the FIRST LEGO League World Class COMMUNITY TREE
- Rubber bands - LEGO robot attachment that triggers with a motor
- Rubber bands - LEGO robot attachment triggered with a motor - part 2 removing the motor
- Rubber bands - one more way to remove the LEGO attachment dependency on the motor for triggering
- Rubber bands pinless attachment for taking loops
Other pinless attachments:
Building instructions for the LEGO Mindstorms attachment using Rubber Bands
In his video we'll use our rubber band attachment to solve the 2012 Senior Solutions competition model, the oven. Previously we used this for taking the loop and now we're gonna use this for the oven.
As a reminder, this here is the competition model. It's a very interesting challenge because you must find the way to take this lever half circle and all the parts at the end must be black, all the parts that are facing up. Initially we have two black parts, two red parts and at the end we must have four black parts. So it's a complex mission and you can solve it with the motor, you can solve it with the rubber band. It's a little bit difficult to solve this mission with a passive attachment, attachment that does not use any motors or any rubber bands. And in today's video we will use attachment with the rubber band. This here is the attachment that we built. Just a small demonstration how the attachment works, we load the attachment. As we can see, it has a lever with a rubber band. And when we push on this axel here, this whole module will move back and it will release the lever like this. Again we load the attachment, we push on the axel and the lever is released. The rubber band is released and we can solve the mission. Now the whole attachment is, again, a pinless attachment. It's very easy to attach the robot. Just place the robot on top of the attachment and that's it. Very fast, very easy. Now let's see this in action. I'll turn the robot so that you can see it on camera. Now the robot is again moving on the field. It somehow reaches the mission model and we push to the oven. And as we push to the oven, the lever is rotated and we can see all the black parts here. So this working like 100% of the time. It's very interesting to see this second rubber band here. The purpose of this rubber band is to ease the loading. If we remove the rubber band. As you can see when we load, it's very difficult to fix this whole module. Because of the pressure from this rubber band, these axels are moving back. That's why we must add a second rubber band. And now it's very easy to load. This is a principle on how you can use levers and rubber bands. Of course the attachments will be a little more complex because we have this white part here for navigation and for easily moving to the oven. But at the end we just move to the oven, push. And as we push, the mission is solved.