Friday, September 18, 2009

Motors are hard to attach, let's play with the wheels!

Today was the first day of the second week, which was "build a sturdy car". We showed them the sample car from the curriculum, which was - intentionally - pretty lame, but the net result was that most of the kids just completely froze on the problem. After all, look at them:

Most of the obvious ways have bits getting in the way or end up with the wheels pointing the wrong direction. This was my moment of quiet panic. So, we showed them the basic double-joiner elements:

and they got the idea that you could use those to directly attach the motors to the sides of the NXT brick. So, most of the cars were wide, like this:

But there were several interesting designs:

Nevertheless, too many kids didn't know where to start and endured a lot of frustration. We still want them to wrestle with the design process, but some of them clearly needed some hints. So, I found this great resource from the LEGO Engineering site: Constructopedia 2.1 | Ways to Attach NXT Motors (PDF, 29 pages) It shows 8 different ways with detailed building instructions. Since we don't want to take away all of the "fun", I think that we might just provide copies of the overview picture for each design - to be used as needed. (Oh, and even if we give them a solution for motor attachment, they still have to figure out the "front" wheels.)

End-of-week update:
Providing the motor attachment hints really helped. Most of them (that needed the help) were able to get by with just seeing the overview picture, not the detailed building instructions. Here are some of the other cars:


  1. My 3rd graders did the "Build a Sturdy Car" activity today. As I observed this lesson in a 5th grade class last week, I questioned whether either my students or I were up to this task. Over the weekend I discovered it was fun to build a simple car and very satisfying to see it run around the room, so I became more confident that my students would like this activity and be able to do it.

    I gave my 9 pairs and one solo worker 4 minimal directions: 1. attach 2 motors, 2. add wheels, 3. attach two wires, 4. program it to go. I showed them my simple car and told them to do the first two steps with their partner and that I would help them with steps 3 and 4 when they were ready.

    7 pairs built reasonably sturdy cars that could run around on the floor (and were quite delighted about that). Two of the 7 cars fell over when they first started to go. Those students didn't hesitate--they picked up their car immediately and went back to their table to modify it.

    The other three pairs came close to finishing (they were mostly challenged by the front wheel attachment). I think if we had either 20 more minutes or the help of an engineer, all the students could have completed their cars.

    Four of the pairs presented their cars to the class. Just as I had observed in the 5th grade, one of my extremely shy students, who never speaks up in class, seemed amazingly comfortable describing her car design to her peers.

    This was a thrilling and satisfying activity for 3rd graders.

  2. Glenn, What curriculum are you referring to? We are doing a robotics camp this summer and were looking for some guidelines on what we should cover.