"Perpetual" Marble Machine

I facilitated the Westport Library's Teen Tinker Camp this week. We started with an ambitious project: build a "Perpetual Marble Machine." Many of us have built marble machines, or marble runs, where the marble travels from the top to the bottom. I do not know anyone who has built a marble machine where the marble travels from the top to the bottom, then from the bottom back to the top, to potentially put the marble in a perpetual loop. 

The project introduced the makers to the concept of bricolage, a term meaning construction using materials you have on hand. Instead of being siloed, distinct play sets, a maker should come to see tools such as LEGO, the MaKey MaKey, and Scratch as parts that can be combined in new and interesting ways to bring different capabilities to their constructions.

I briefly introduced the students, ages 10 to 13, to the MaKey MaKey in case they had not before worked with it. One student explained that you could hook conductive materials to the MaKey MaKey so when you touched the materials things could happen on a computer. 

When asked, another student said Scratch "allows you to do anything you want." I also showed them how to connect the LEGO WeDo kit to a laptop and read sensor values and set motor speed. 

After that I got out of their way. They did some quick brainstorming about potential features of their perpetual marble machine. I captured their thoughts on an easel. 

They had a diverse set of materials to work with: MaKey MaKey, Scratch, LEGO, WeDo, wood ramps, pipes, cardboard, LEDs, copper tape, string, and anything else within reason they could think to ask for.

Some students immediately started constructing the marble machine with the parts with which they were most comfortable working.

Other students started with drawings of anticipated construction.

Gradually, more sophisticated materials started to be incorporated in the marble machine. LEGO, while familiar to the students, had not yet been programmed by them, so they worked with additional challenges presented by the material.

Students started timing how long it took the marble to travel the marble machine, anticipating beating the established record of 12 seconds on this particular board. They were never prompted to time their construction, but elected to do it on their own. They discovered the addition of funnels could significantly slow the marble's progress.

The students iterated on some designs that ultimately were discarded because they did not function as needed. However, their willingness to experiment and accept the failure of individual parts was notable. 

Providing ample materials and a large enough marble machine peg board meant everyone was included in the project. People freely exchanged ideas, tried construction techniques, and added individual and group constructions to the machine.

By the end of day one the marble almost made it through the machine.

Day two saw the introduction of the MaKey MaKey into the Perpetual Marble Machine. One student, fiddling with cardboard, built a switch. She pursued the design, building it from paper, until she realized the design pushed the marble off the ramp.

With my help, we constructed a ramp that used strips of conductive copper tape to create a circuit. When a marble was covered in aluminum foil and rolled down the ramp, it closed the circuit. A small Scratch project to play notes when keys were pressed was written, and the ramp was connected to the laptop with a MaKey MaKey.

It did not take long until the girls programmed "Old McDonald" to play as the ramp was used!

Another student built a circuit with LEDs to give the Perpetual Marble Machine bling.

The LEGO WeDo group incorporated the MaKey MaKey switch used in the Old McDonald ramp to start the motor that lifted the marble back to the top. They fine tuned the speed of the motor and the string collection system.

By the end of day two the Marble Machine was nearly Perpetual!

The students wanted to work for a little longer at the beginning of day three. One student, who worked hard day one but was detached, though working on the periphery during day two, revealed her big contribution to the project: an augmented reality layer built in Scratch! It took some wrangling to position a projector on top of the table so an image was projected onto the pegboard at the right size.

The Scratch project added a ladder behind the LEGO WeDo elevator, as well as virtual ramps projected over the real ones.

The programmer could drive a virtual bike in the augmented reality layer. The bicycle appeared to drive along the real ramps!

The final construction was an engineering, wiring, programming, circuitry work of magic constructed over seven hours of hard fun with minimal scaffolding or support from an adult. Skills such as circuitry were taught on an as needed basis, while major skills, such as how the MaKey MaKey works, and how LEGO WeDo can be controlled and read by Scratch, were taught to the entire group. Not everybody finished knowing how to construct a circuit, but those who did construct a circuit taught other people in the group the skill, too.

The students who participated in this project learned a wealth of new skills. They were bricolageurs, combining familiar materials like cardboard or LEGO with new materials, like Scratch and the MaKey MaKey, in novel ways to solve a problem. The project required collaboration in order to succeed: each participant added to the project, influenced its construction materials and techniques, and helped solve the challenge. The project involved just-in-time learning of new skills by individuals to solve additional challenges that the students themselves created, like making a musical ramp or a ramp that lit up with LEDs. Not everybody learned to build a circuit, but the students who learned the skill from me, the adult, taught the skill to the LEGO WeDo group to help trigger their motor. Even though the construction did not become perpetual, the students concluded the project as enthusiastic as when they started but with new skills, too.

Projects like this are meaningful, differentiated skill building exercises that equip students with the flexible thinking, fabrication, and collaborative skills necessary for the jobs they will create for themselves as adults. As educators, we owe it to our students to present them with such meaningful opportunities for the construction of knowledge about subjects that interest and compel them.