If the copper in pennies is worth more than 1 cent, why aren’t people melting pennies to get rich?

You may have read that a penny costs the US Mint more than a penny in material costs. Is this true? Should we melt pennies to get rich? We will explore this topic.

Photo by Jonathan Brinkhorst on Unsplash


For much of their history, US pennies were mostly copper. Pennies made on or before 1982 were, made with 95% copper and 5% zinc. (Post-1982 pennies are 2.5% copper and 97.5% zinc)¹.

From this, it would seem that it’s a good idea to melt pennies for their copper. Though it’s currently not legal to melt pennies for monetary gain², let’s temporarily imagine the US phased out the…

Photo by Taun Stewart on Unsplash

There are a ton of Teslas on the coasts of the US. And because they all look the same, Tesla owners love customizing their cars.

Here are some aesthetic and functional accessories to make your Model 3 your own.


EV owners are obsessed with efficiency. A spoiler reduces drag by “smoothing” the air behind the car. Less drag means higher efficiency.

This is one of the reasons why the Model 3 Performance has a carbon fiber spoiler on top of the trunk! For other trims, a spoiler can be easily added.

When I added my spoiler to my car, I…

A Technical Literature Review

This literature review was originally written in December 2017 by Matthew Cheung, for the graduate-level course ME 290R (Topics in Manufacturing — Nanoscale Manipulation of Materials) at the University of California, Berkeley.

Photo by Christian Wiediger on Unsplash


Historically, microprocessor die size has stayed relatively constant. While performance has increased due to the increased number of transistors, total microprocessor package heat production levels have stayed relatively stable. Thus, in order to further increase computational density beyond increases due to Moore’s law, microprocessor cooler manufacturers have been pushing to make coolers smaller, even attempting to integrate cooling systems into the microprocessor dies themselves. …

This Could Save You a Ton of Money

If you’re like me, you don’t enjoy paying taxes.

I understand that taxes are sometimes necessary, but at times, they can be burdensome.

Photo by Joshua Rawson-Harris on Unsplash

I live in the San Francisco Bay Area, where sales tax (paid to the California DMV) when registering a new car is about 9.25%.

Photo by Bram Van Oost on Unsplash

One question that Model 3 owners get a lot from people riding with them is “how do I open the door?”

People who have never ridden in a Model 3 before typically don’t know how to open the door, often pulling on the emergency release lever. Unfortunately this can damage the window or the window trim. This is because the windows does not lower when the emergency release lever is pulled and so the window hits the window trim.

You can prevent this issue with these “OPEN DOOR” stickers¹. And if a passenger does ask how to open the door…

Photo by Charlie Deets on Unsplash

EV drivers hate noise. Wind noise is air howling at you. And tire/road noise is an equally annoying hum.

How is wind noise and road noise is produced? I’ll explain both of these and then present solutions to reduce the noise. The goal is to make driving the Model 3 a more pleasant experience than it already is.

Wind Noise

Wind noise is caused by wind hitting the cars surfaces and catching in the panel gaps. This causes turbulent airflow. The more turbulent the air, the noisier it is.

One major source of wind noise are the gaps in the panoramic sunroof…

Coffee. Work. Snacks. Work. Lunch. Work. Snacks. Work. Dinner. Sleep.

Photo by Krisztian Tabori on Unsplash.

In Silicon Valley, there are quite a few Product Design Engineers. We are mechanical engineers who design consumer electronics or hardware. Think: the people who make sure your phone doesn’t break after one drop.

For example, at my previous role at Apple, I designed, prototyped, and tested next-gen MacBook hardware.

People wonder what my day looks like so following is a typical schedule:

Typical Schedule


5:30 AM: Morning activities.

  • Wake up, change, brush teeth, etc.
  • Read some early morning news. Potentially make some pre-market stock trades or set up some trades to occur during the day.
  • Work on the side business.


Photo of a Tesla Model 3 by Bram Van Oost on Unsplash

I had the opportunity to drive a Tesla Model 3 Performance on and off for about a month. It’s the one with the long-range 75 kWh battery pack, the dual motors, a fancy carbon fiber spoiler on the trunk, and Tesla’s special sauce firmware that makes it go fast. It also had Autopilot (and the Full-Self Driving package).

For background information, my “normal” car is a pretty old 2000 BMW 3-Series coupe.

1. Most electric cars are slow, but Teslas are not slow


The Model 3 is incredibly quick. Tesla claims that the 0–60 MPH time is 3.2 seconds. However, it’s actually quicker than…

Why do you need 5 monitors?! — Basically Everyone

My desk in all its glory. Everything that isn’t my desk was intentionally blurred-out to obscure potentially proprietary information. Photo by Author.

At my office, most people have 2 displays (1 laptop and 1 external monitor).

Some have 3 displays (1 laptop and 2 external).

Very few have 4 displays.

I have 5.


I am a product design engineer (mechanical engineer) working in Silicon Valley.

Working with talented industrial designers, electrical engineers, manufacturing & industrial engineers, and program managers, I currently design products for light electric vehicles. (Perhaps check out my day in the life article?)

My previous adventures include SpaceX, Apple, and Tesla (Elon Musk said “hi” to me one time).


Racecars are really cool. But how do I design formula-style racecar?

People have asked me how to design a racecar and how to start a Formula SAE (FSAE) team at their universities. The goal of this article is to help those individuals jump-start their FSAE adventures.

As a little bit of background, I was a suspension design engineer on the UC Berkeley Formula SAE Team for a little over two years. And I had a part in the 2015 and 2016 racecars. In 2016, the team placed 11th out of 70 at the Formula SAE Lincoln competition.

Me in the Berkeley Formula SAE Team’s 2016 racecar at Formula SAE Lincoln. Lincoln, NE. Jun. 2016.

There is a…

Matthew Cheung

iPhone Product Design Engineer @ Apple | Formerly Tesla, SpaceX, Boosted | Berkeley Mechanical Engineer | Based in Silicon Valley

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