Tag Archives: engineering for kids

Engineering Challenge: Ping Pong Ball Zip Lines

OLYMPUS DIGITAL CAMERAFor our March Engineering Challenge we built devices that would carry a ping pong ball down a piece of fishing line. I got the original idea from  a PBS Kids Design Squad activity, which I then adapted a bit for a wider age range.  The original challenge suggested using 4-5 feet of fishing line, as less was too short and more was likely to sag. I didn’t measure exactly, but I know the width of the stage area in our meeting room is about as wide as I am tall, which makes it roughly 5 feet.

The children were given straws, pipe cleaners, paper clips, egg cartons, spoons, washers, paper, and tape. The initial challenge was simply to build something that would carry the ping pong ball down to the bottom of the line. I had a whole “and the stage is made of pingpong lava, that doesn’t hurt you, but will burn up your pingpong ball!” story to help forestall the inevitable wise-guy just letting the ball fall and bounce to the end of the stage. My audience skewed younger – of the 30+ kids, I’d say at least 20 appeared to be 8 or younger – and they really bought into the lava story with enthusiasm.

With my engineering challenges I like to have multiple levels of challenge. Once a child has completed the first level, I give OLYMPUS DIGITAL CAMERAhim or her the second challenge. This way I can differentiate everyone’s experience, allowing everyone to walk away feeling successful. Some kids will only complete the first level, other kids will complete several. For this challenge, the second level was supposed to be similar to the PBS Design Squad rules, which was to make the ping pong ball travel to the bottom in less than 4 seconds. However, I ran into a problem, in that all of the vehicles managed to do this on the first build, essentially erasing it as a challenge.

At first, I thought perhaps the lines were not at the right angle. The original challenge also suggested an angle of about 30 degrees. Re-evaluating the lines, I decided they were probably more like 45 degrees. I lowered two of the four lines to be closer to 30 degrees, but that didn’t seem to make much of a difference. I decided to change the second challenge to be to see how slowly you could make the ping pong ball go down the line.

OLYMPUS DIGITAL CAMERAThe older kids seemed to really get into the challenge of making it go slowly, and were pleased with their results. At the beginning of the event, I had emphasized that the Engineering Process involves constantly testing your design and then going back to improve it. I was trying to forestall frustration in what I had initially deemed to be a true challenge for the younger-than-average audience, but apparently the kids took the message to heart. Despite the fact that it actually ended up being a fairly straight-forward challenge, many of the children went back and redesigned their vehicles, even after meeting with success, so that they could “be the best possible.” Some of the children spent a lot of time each designing several separate vehicles using different materials so that they could determine which one worked the best. Most of the children were so caught up on redesigning and recreating that they never came to me for a second level of challenge, but that was more than okay, as the point of the exercise was to have fun, feel confident about building things, and walk away thinking like an engineer, all of which were clearly accomplished.


Engineering Challenge: Roller Coasters

Roller coaster engineering challengeOur January Engineering Challenge theme was roller coasters. Before we started, I talked a little bit about momentum, demonstrating that a marble rolled along a mostly flat track will stop, but a marble rolled down an inclined track will keep going, and that marble rolled down a very steep track can build up enough momentum to keep going even uphill. Most of the children nodded along, as this was all well within their life experience of how balls interact with the world.

Once they had the general idea, I gave them the first challenge: to build a roller coaster that allowed the marble to go up and over a hill. I purposefully make my first level of challenge relatively simple so that every child participating will have at least one success by the end of the program. To accomplish their challenge the children were given pipe foam that I had cut in half lengthwise, forming a channelled track. The pipe foam was perfect for our purposes: very flexible for young hands to manipulate and very cheap at at about $1 for a 6 ft tube, which provided 2 channels. I also gave them access to lots of tape. I had regular masking tape and also painter’s tape, which I Roller coaster engineering challengeemphasized needed to be used if the children were going to use the wall as part of their building process. (And here I’d like to put in a plug for painter’s tape. It’s more expensive than regular masking tape, but otherwise so much better! Unlike masking tape it never takes the paint off the walls. It’s also much easier to peel off the roll, a problem we’ve had with several different brands of masking tape. It’s almost as sticky as masking tape, and I’ve successfully used it to hold posters up on the wall for as long as I wanted the poster to stay up.)

We had about thirty kids working on the challenge, mostly in small groups and pairs. There were a significant number of dads with their children, which is always exciting to see. I love watching the parents get involved with the engineering, and the great discussions the parent/child interactions produce. The kids are often more accurate in their predictions of what will happen! Maybe because they have spent more time messing around with similar materials?

An engineering challenge roller coaster Our second level of challenge was to create a loop-the-loop. This was significantly harder, but everyone got there eventually. I like to emphasize that engineering requires a lot of trial and error. I did not see any frustration, all of the participants were confident that just one more tweak to the design would yield results.

I told the children who completed the second challenge that they could either do a free design, or they could try for two loop-the-loops. Most chose to try for two loops. One thing I noticed during this program was that it was not enough for the children to accomplish the task: they needed me to be a witness to their success. This meant running around the room quite a bit so that I could personally watch marbles rolling around the tracks. The looks of delight were definitely worth it.

Engineering Challenge: Newspaper Structures

A girl kneels in the newspaper structure she builtFor this Engineering Challenge we built structures that were large enough to fit inside using nothing but newspaper and masking tape. The structures had to be free standing, but did not need to have walls, floors, or a roof.

Before the program started, we talked a

little bit about  the shapes that make for a stable structure. Some of the children had participated in a previous building workshop and remembered that triangles are excellent

 weight bearing shapes. We also talked about different ways to use the newspaper, including folding, rolling, various rolling techniques, and other ways to build with newspaper. I let the children know that “fit inside” could mean a lot of different things: standing, sitting, lying down or anything in between. Each position would bring its own set of challenges.

There was a lot of parent-child interaction, and a lot more child-child grouping for this project than for some of our previous Engineering Challenges, which made for a loud and boisterous time, but also created some great conversations about material properties, physics, engineering, and the building process.

A family fits inside their newspaper structureFor our previous challenges I had set up multiple levels of challenge so that even if someone was successful immediately, they could still remain engaged in the process. For this program, however, the second levels of challenge were essentially unneeded. The time it took to roll the newspapers, plus the inherent difficulty of the challenge and the general need for most of the participants to try several ideas meant that almost everyone required the entire hour to simply complete their project. I suspect some of our younger participants would have needed a lot more time if they had not been partnered with an older friend or had help from a parent. We had one family of young children that was kept busy the entire time building as a team with their parents so that the entire family could fit inside their structure! The little kids worked to roll the newspaper, while the older children and parents designed the structure and figure out the best way to implement their design.

A girl lies in the newspaper structure she built

The level of engagement in the room was extremely high. They were all determined to make their structure the best possible, despite the difficulty of the challenge. I was a little worried that the frustration level would be high, but I was pleasantly surprised to see how willing the students were to recognize that something wasn’t working, analyze why, and then try again with a modified strategy.