How do etch-a-sketch’s work?

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How do etch-a-sketch’s work?

In: Technology

Contrary to popular belief, the stylus you use to draw doesn’t draw the line.

The inside “screen” of the toy is coated in aluminum powder, and when the stylus scrapes it out, it reveals the darkness inside the toy. When you shake it upside down, the beads inside the toy coat the screen, making it look “blank” again.

EDIT: Funny how you marked it technology.

The etch-a-sketch is filled with a sticky aluminum powder that coats the screen when you shake it upside down. Inside the machine is a stylus that rides on the screen and is connected to two sliding rods that are moved by cables attached to the control knobs. Turning the knobs slides the stylus acrosss the screen scraping off the aluminum powder and leaving a dark line in the screen.

[This](https://thedayintech.files.wordpress.com/2013/07/etch1.jpg) is the machinery inside under the screen.

You can see how an etch-a-sketch works by drawing over the entire screen.

As you draw bigger and bigger black spots, you start to see through. The lines aren’t black ink. The lines scrape off a powder coating on the inside of the glass, exposing the inside. When hardly any of the screen is clear, the inside is dark, so you see a dark line. But as you start to clear off bigger areas, you see inside. What’s there is a sort of stylus, pressing against the screen, and a vertical and horizontal bar which move the stylus around when you turn the knobs. The stylus scrapes the grey powder off off the glass. There are also a bazillion tiny balls. When you turn the etch-a-sketch upside-down to “erase” it, those balls spread the grey powder all over the glass, covering up the parts you cleared off.

Try it! It’s cool.

A needle scratches dust that’s inside when you turn the knobs. Shaking it puts the dust back.