An illustrated celebration of the engineering around us
HEIGHT-FULL
SPACER
#NAV-APPEAR
Why the Mechanical Pencil?
This was the first product I decided to teardown and analyze for this project.
Despite using this Bic pencil for several years, I had never considered how it actually works. But it turns out, there is a simple magic trick waiting on the inside.
The main question: Why does the lead continue to press out, when the eraser is pressed and released?
There are countless mechanical pencil designs from history, and surely some fancier mechanical pencils you could use, but this Bic pencil is still being mass produced and selling in the exact same form almost 40 years later. Let's take a closer look.
Why the Mechanical Pencil?
This was the first product I decided to teardown and analyze for this project.
Despite using this Bic pencil for several years, I had never considered how it actually works. But it turns out, there is a simple magic trick waiting on the inside.
The main question: Why does the lead continue to press out, when the eraser is pressed and released?
There are countless mechanical pencil designs from history, and surely some fancier mechanical pencils you could use, but this Bic pencil is still being mass produced and selling in the exact same form almost 40 years later. Let's take a closer look.
What Are The Main States of This Design?
Before we get into the inner-workings of the pencil, we should establish the static states of the design. This will help set the stage for future analysis.
What Are The Main States of This Design?
Before we get into the inner-workings of the pencil, we should establish the static states of the design. This will help set the stage for future analysis.
What's Inside the Pencil?
Let's take the pencil apart and find out what parts live inside.
What's Inside the Pencil?
Let's take the pencil apart and find out what parts live inside.
Lead
Spring
Chuck
Housing
Cap
Clamp
Tube
Let's Take a Closer Look at the Chuck
More than any other part, the chuck makes the whole pencil work. Similar to a chuck in a hand drill, this chuck clamps down on a radial object. In a drill, the chuck holds the drill bit. In a mechanical pencil, it holds lead.
The chuck is a molded plastic part with a hole for lead to travel through. It has one job to do: grip & release the Lead
Let's Take a Closer Look at the Chuck
More than any other part, the chuck makes the whole pencil work. Similar to a chuck in a hand drill, this chuck clamps down on a radial object. In a drill, the chuck holds the drill bit. In a mechanical pencil, it holds lead.
The chuck is a molded plastic part with a hole for lead to travel through. It has one job to do: grip & release the Lead
cut through center allows Chuck to flex open & close
hole for Lead to travel through
cut through center allows Chuck to flex open & close
hole for Lead to travel through
Let's Look at the Moving Parts
To better understand the mechanism, let's walk through some critical parts.
Let's Look at the Moving Parts
To better understand the mechanism, let's walk through some critical parts.
Okay, Time To Walk Through the Mechanism
Let's walk through the pencil mechanism, step by step, to understand how it all works
Okay, Time To Walk Through the Mechanism
Let's walk through the pencil mechanism, step by step, to understand how it all works
