Robotics Grade 3

Our task was to create a robot to fetch and carry water back to an African village, when it sensed that the container of water for the village was low. This involved a lot of thought about both design and programming. After much preliminary work on gears and gear ratio, the students were to create a strong and stable robot that would run efficiently. All parts needed to be anchored well.

Students decided that a light sensor would help the robot find the river. Because the sensor was looking for a darker coloured river, the robot was to sit beside the village on light coloured sand. Upon reaching the river the robot needed to stop, then because the sensor was over a dark river, it would have to back up a little in order to start from a light surface again. After filling up, the robot would return to the village, stop on a dark strip, and then move forward to the light sand, ready to begin again. We started our robot with a touch sensor, simulating the weight and lack of weight of the water as our trigger to start the robot moving.


We had lots of problems but we persevered and we were successful. When we put our wheels on, we forgot to put the gears on first so we had to take the wheels off and start over. Another day our motor wasn't working. So we changed the wires and motors and it still didn't work. We had our motors on A and B. One day our program accidentally got deleted! Our favourite part was programming and testing out the programming.
Becky, Lual, Megan
We started off the unit by building gear trains horizontally and vertically.
Then we built our chassis but we had to take it apart three times because the chassis was not strong enough and another time the axles stuck out too far. We couldn't make up our minds whether to use wheels or treads but decided to try treads anyway. We were especially happy with our program and our robot worked really well.
Beert, Drew, Tyler

It was very hard in the beginning because the chassis kept on breaking, but when we got the RCX box on, and the motors, everything worked out just fine. When we programmed our robot it worked just as we had planned. On our Celebration of Learning, we showed it to the parents. And it ran perfectly!
Evie, Rachel, Saniya
This is our robot Mr. Roboto. Our biggest struggle was programming. It is very difficult because you can't make any mistakes or else the robot will not work. Our robot worked some of the time but it kept sensing the tape holding the landscape together. We couldn't figure out how to bring the "value" down low enough so it wouldn't sense the colour of the tape.
Davis, Daniel, Kelsen
We had something different on our robot because we had chains, while most other groups had to work with gears. We taught the other group with chains how to make their robot go slower. Our robot broke five times or more. That was definitely a frustration but we got it fixed and our program up and running.
Brodie, Harrison, Kaden
When we made our robot we tried using treads first, but it didn't work so we used big wheels. It worked perfectly. Because we were the first group to finish, we got to use chains for our wheels. We didn't have to put on a gear train because we used the chains. Then we put on the RCX box and a motor.There was no friction when the robot moved forward.
Arthur, Nibras, Noah
At first our robot would sense the black cracks between the boards of our landscape. We had to change the ratio of the light sensors. After that we had two major problems. One of the problems was that the gears were rubbing on the chassis and the other was that it was running into the village and destroying it. Our group really worked well solving problems together.
Craig, Gavin, Hugo, Myles
Our robot's name is Flipper. We named it Flipper because it had a water hose as a nose. We had three motors on our robot because it had one to drive the treads on each side of the robot and one to work the hose. We had really good teamwork that's why it worked so well.
Anna Jean, Jami, Sydney

Copyright © 2006 J. Grimm, N. Klinger and L. Ranta

Copyright for students' work remains with the authors.