Box Robot for Robotics Competitions. Use of motors Pro Preview

In this video we look at the way this robot uses the LEGO Mindstorms EV3 motors. How are they attached and the what the rotation of the motor is transferred to the attachments.

  • # 287
  • 30 Aug 2016
  • 4:55

We have provided the building instructions for this robot as part of the whole course 

Box Robots for competition (this will require a course subscription)


In this video I'll stop at the way this robot uses motors. And you can see that it has 4 large motors and a couple of sensors. So, let's take a look at the motors.

We have 4 motors with this robot. Two of the motors are responsible for moving the robot and two of the motors are responsible for this care wheels here. If I now move one of the motors you can see this part here rotating and I can move it forward and backward and the same for this part. And from here we can have different attachments. We can have attachments that are on the top of the robot or we can have attachments that are at the front of the robot. And we also rotate that gears at the front. And we just rotate them forward and backward. And the other one here. As you build the robot and as you look at the building instructions you can see the specifics of how exactly we tranfer the movement from the motors to these parts here at the top at which we add the different attachments. And two of the motors are responsible for the attachments. The other two motors are responsible for the movement of the robot. We have two main motors and we have the wheels with the tires attached to this motor. And we just move forward, backward and we can turn. Now, this robot involves it includes four motors. It is possible that you might have only three motors. Or you can have two large motors or one medium and you should modify the construction inside. And while building you'll see ways to modify it and you can add only one of the motors or if you have more motors or you feel the side to purchase more motors you can have 4 motors with this robot. And it will give you more opportunities for controlling the different attachments. The wheels of this robot are actually with an axle. And this axle is touching the robot on two places. First, the motors and then on the frame. And this makes the axle very stable. It will not band under the heavy attachments and under the load of the robot. And that's about the different motors. Again, you can see the building instructions and how exactly we transfer to it with a few gear wheels the movement from the motors to the top of the robot where we add the different attachments. Looking at the sensors it is always a very good idea to use a light sensor in a mission light ot colour sensor. And this sensor is very convenient to be placed at the centre of the robot. So we have one sensor here and it's a colour sensor and it's in the centre of the robot. In this way we can follow different lines. And we also have one more sensor imagine that this is a colour sensor, I don't have a colour sensor currently so I added this gyro sensor. But it should be a colour sensor. And this colour sensor could be used for aligning the robot. Bacause to align a robot to a line we need two light sensors. And this sensor can align the robot. So, one for following and two for aligning. Do we need an ultrasonic sensor? Well, on this robot we haven't add an ultrasonic sensor but it's a good idea to have one. And for the gyro. And you can find different places for the gyro and I do recommend to add it inside the box. And this is one of the tasks here. Try to add a gyro sensor inside of the box. There is place here I'll give you a hint. Just here beneath the brick. There is place for the sensor. In this way you have the robot with three sensors and you have one more sensor that probably you can add second sensor if you need and if you have. And that should be enough for rules in any competition. So, 4 motors, 2 or 3 sensors. 2 light sensors - one for following and two for aligning and one more gyro sensor that could be added right here.