This week-end we took part in The Deconstruction, as « The Carrots of Patagonia ». Our project was to deconstruct photosynthesis into a Rube Goldberg machine. Our machine starts with a light bulb and ends with a sugar cube. It was a way to show how incredibly complex this process is and how energy conversion is a huge part of it, rather than to « teach » something. To make a long story short, we failed to represent photosynthesis accurately (too complicated...) but we had fun!
Here is an overview of what we built during this 48h event.

But because every Rube Goldberg Machine is what you want it to be, we are not going to do a step-by-step guide for the exact machine we've built. Rather, we choose to present you with a toolbox with all the technical tricks we discovered by trial and error to build the things we envisioned.

Here are some solutions for these technical puzzles:

1. How to trigger a domino cascade with a light bulb
2. How to build a seesaw
3. How to reception a projectile propelled by a seesaw and channel its energy into moving a ball
4. How to build a straight railway
5. How to use a ball going down a railway to drop an item
6. How to build a catapult
7. How to trigger a catapult with a rat trap

Step 1: How to trigger a domino cascade with a light bulb

You might say triggering a domino cascade is a pretty easy thing. And you'd be right: just push the first domino down and here you are!

But we wanted to trigger our domino cascade with "light", because the starting point of photosynthesis is light.

So we used a pendulum design where a light bulb knocked the first domino down.

As you can see on the picture, the light bulb is swinging on the side of a cardboard. It is hold by a metal piece that was coming with it, so except if you have the exact same old recycled lamp home, you will have to find your own way to attach the electric cord to the cardboard.

The electric cord is optimized so the light bulb is just half a centimeter above the platform after it's fallen.

We used forks stuck into the cardboard to both hold the light bulb in waiting position and stop it when it's down.

The first domino is put just before the second fork. You will have to calibrate it so the light bulb knock it down with the exact strength you want, but here are a few general tips:
Leave enough space between the domino and the fork for the domino to be able to fall.
Don't put the domino to close to the cardboard else it might be knocked against it by the light bulb.
Don't put the domino to far from the cardboard either, or the light bulb might swing between the domino and the cardboard.

If you can, put something on the fork to take up the shock, like foam. We didn't do it and after about a hundred tries (to calibrate the rest of the machine), when the machine was finally ready to run, our light bulb died.

Hmm, maybe I should make one like this- it's triggered by opening my bedroom door, which. . . . . . . . . . . .The intruder is left soaking wet :D
Sounds great ^^ Send us a photo if you do :)

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Bio: I'm a biology student interested in education and innovation.
More by LaChapeliere: Useful technical tips to build a Rube Goldberg machine : Deconstructing photosynthesis
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