In this episode we introduce a LEGO Mindstorms EV3 version of competition robot construction. It is a modular construction, with medium motor for aditional attachments and two light or color sensors for orientating on the field.
- # 58
- 03 Nov 2014
In the video we take a look at the construction and point out some key characteristics of the construction. Under the materials tab you can find pdf instructions for building the construction from the tutorial. Use the video as a reference to lock the modules together.
If you find the robot too wide, just take out the side frames. If you do not posses two EV3 color sensors, do not worry, just use old NXT light or color sensors.
For any suggestions or questions, just post your comment bellow.
In this tutorial I'll show you an EV3 construction that could give you ideas for building your competition robot or you could just use it as a base for your robot. It consists of two large motors that drive the robot, one medium motor that could be used to power additional attachments, two light or color sensors for orientating on the field and, of course, a brick.
Below the materials tab following the video you could find pdf instructions on how to build these modules. There is also a pdf file where you could find instructions on how to build the whole robot. Now, I'll assume that you have already built the modules and I'll go through the process of assembling them and focus on some of the key features of the construction. First of all, we have the two large motors and you may notice that there are these Lego pieces at the back of the motors. Their purpose is to hold the cables firm so, before we proceed with building the robot, we have to take them out, take a cable, put it into the motor, hold the cable firm and put the Lego pieces back.
This is quite a good technique to have the cables in place and you could use it in other constructions as well. Now I'll do the same thing on the other motor. Again, put a cable into the motor, hold it firm; and put the Lego pieces back.
OK. Now I can proceed with building the robot. First, we have the front frame. You attach the two motors onto the frame. Like this. And the other on the other side. Then, you have the back frame that should go into the three holes at the back of the motor. First, I'll attach the first motor and then the second one. OK. Then you have the back wheel which, as you see, has this flexible pin which is turning. You have to put it into the middle hole of the back frame. Here.
After you put it, place back the back wheel on the back frame and press the red pin so that it will lock the back wheel. As you can see, it's firm now. OK. Next, we have the sensors. In the instructions we use two EV3 color sensors but you could use one EV3 color sensor and one NXT light sensor if you do not have two EV3 color sensors. So, I'll attach the sensors to the lower two points of the frame. Then, I'll attach the EV3 color sensor.
Then, we have the medium motor. We use these four blue long pins to attach it to the front frame. So, they should go into the four wholes on the upper part of the frame. I'll attach them.
OK. Next, we have the shield which has several purposes but the main one is to cover the two sensors so that they will be more accurate. I'll just attach it to the angled beams. OK. The holder has fallen.
So, I'll put it back.
Next, we have the side frames. They are attached to the motors via these two black pins. So, they go in here - in the two holes. Their purpose is to hold the wheel from the outer side because if you just hold the wheel to the motor, it will move all around and it will be inaccurate while moving on the field. OK. I'll use the red pins in here and at the back to lock the frame. Now, as you can see, the wheel is hardly moving while the other one is quite unstable. So, I'll put the other frame on the other side. Again I'll attach it to the motor using these black pins.
And lock it with the red pins.
OK. Now it is a good time to attach a cable to the medium motor because when we put the brick onto the robot it will be difficult to place the cable inside. So, I'll attach the cable. The cable should go through the back frame. Then I'll put the brick onto the construction.
OK. Finally, I'll connect the cables to the brick.
And you have your construction ready.