I’m crazy about building the weirdest and coolest things. Here’s just a snapshot of stuff I’ve worked on.

From Mars rovers to high altitude balloons to piano-playing robots.

Who even am I…

My name is Samuel Chen, and I’m currently a Reliability Engineer at Meta. I’ve done everything from launch robots really fast at Mars to design new hardware for consumer electronics.
I’ve been in the consumer electronics industry for about 4 years now; first at Amazon Lab126 working on wireless earbuds and FireTV connectivity solutions, and then currently at Meta working on AR/VR devices. In the past, I was also a part-time employee at NASA Jet Propulsion Laboratory for 2 years. I specialized in automating and writing software integration tests for a lot of the robotics and motor control features of the Mars 2020 rover (drive system, power distribution, telecom).

just a few of the projects i’ve worked on…click to find out more

PROJECT OVERSEERHigh altitude balloon project — **PROJECT OVERSEER**
High altitude balloon project

MARS 2020 ROVERInternship at NASA-JPL — **MARS 2020 ROVER**
Internship at NASA-JPL

OCTAVE: PIANO-PLAYING ROBOTSenior Design at UCLA — **OCTAVE: PIANO-PLAYING ROBOT**
Senior Design at UCLA

ELFIN CUBESAT PROJECTUCLA’s first CubeSat currently in orbit. — **ELFIN CUBESAT PROJECT**
UCLA’s first CubeSat currently in orbit.

FPV QUADCOPTERPersonal project designing a quadcopter. — **FPV QUADCOPTER**
Personal project designing a quadcopter.

ASHER HOUSEDrew plans for house currently built in WeHo. — **ASHER HOUSE**
Drew plans for house currently built in WeHo.

PROJECT OVERSEER

high altitude balloons at ucla

I’ve just recently started working as a Mechanical Engineer at Project Overseer, which is UCLA’s High Altitude Balloon project. Overseer’s mission is to facilitate research at high altitudes using balloons, which are extremely quick to implement. One of Overseer’s long-term mission plans is to create a modular assembly that can be fitted with any sort of payload and deployed rapidly.

We are currently launching at the rate of one balloon every 10 weeks, and working on speeding that up. My role involves designing the mechanical components for the modular assembly, working on harnessing of electrical components, and testing the failsafe mechanisms. Our current payload involves a Raspberry Pi flight computer, a Tracksoar board, a Pi in the Sky (PITS) board, a tBeacon, and a camera. The mechanical frame is printed on a Dimension Elite out of ABS.

Our balloons are currently 1,500 grams, with plans to expand for heavier payloads. Here are some work in progress CAD renders:

MARS 2020 ROVER

I’ve been working on the Mars 2020 rover for over 2 years now in a Software Engineer in Test role. The Mars 2020 rover is a follow-up mission to the Curiosity rover that was sent by JPL to Mars in 2012, containing new instruments (including one that will generate oxygen on Mars!). I code in mainly Python and Bash, although I do look through flight codes and unit tests in C. Overall I’ve authored at least 40,000 lines of code.

DRIVE SYSTEM

I own the software testing code for the Drive embedded software module. This involved making the rover do donuts to cause it to complain, and also had me wrestle with the rover’s IMU simulation to cause all sorts of weird tilts and bad mechanism angles. I also own the testing software for the Battery Control Board and power distribution subsystems.

AUTOMATION

Most of my work also involves automating a lot of testing and commanding the rover in a way similar to what they would do in actual Mars operations. I help make testing easier by writing internal tools like automated setup scripts and scripts that make other scripts from Excel document inputs because you can never have too many scripts.

AUTONOMOUS PIANO PLAYING ROBOT

So i just watched westworld…

And I really wanted to make something cool and senior design was coming up so what did I do? Built a piano playing robot that plays the Westworld theme of course (cause of that intro scene!). I worked together with 7 other Mechanical Engineering major seniors to put this fun project together.

I handled a bunch of the electronics integration (did all the soldering and was smelling 60/40 flux fumes for days) and worked with my friend Andrew Namgoong on programming the Arduino Mega in C.

cad & mechanical design

The fingers are powered by servo motors are are mounted onto 3D printed baseplates which translate along linear rods using linear bearings. The baseplates themselves are moved using a double belt-drive system powered by two DC motors. The motor mounts were custom-designed and 3D printed, and the linear rods are constrained using shaft collars.

electrical & programming

The servos are controlled using the Arduino Servo library, and the DC motors are controlled using a PID control algorithm implemented onto the Arduino Mega. The PID control algorithm takes input from the encoders on the DC motors, and translates encoder steps into piano key counts. Three limit switches are implemented for calibration and emergency stops, and are programmed to stop the Arduino processor when triggered.

ELFIN SATELLITE

currently orbiting earth around us

I worked on UCLA’s first satellite project, called ELFIN — Electron Losses and Fields Investigation, which was a 3U+ CubeSat launched to study space weather and things like the Northern Lights. On ELFIN, I worked on the mechanical design on the main payload, called the Energetic Particle Detectors. I designed a lot of the PEEK brackets that attach the payload to the chassis, and also some of the PCB board designs for the main Instruments stack. This involved lots of Solidworks designing and working with Fabrication to design for manufacturability.

ELFIN successfully launched on September 15, 2018 on the last Delta II from Vandenberg Air Force Base in California (part of the ICESat-2 mission) and is currently orbiting Earth around us.

FPV QUADCOPTER

flying robots are a thing too

I wanted to make something fun and somewhat useful, so there’s actually a video transceiver and a camera on this quadcopter. The video transceiver talks directly to FPV Goggles so you can see in first-person through the camera while this drone is flying.

Part selection took the longest actually, the soldering job wasn’t too difficult but had to be re-done a couple of times when I added heat-shrink. I also accidentally blew out my first flight controller so that wasn’t very fun but you live and learn, make sure all your solder connections are properly separated.

This project was mostly assembly, but also honed my soldering skills because I was soldering on super small circuit boards so I learned that a fine-tipped soldering iron can work wonders.

ASHER HOUSE

back when i did autocad…

I did a lot of AutoCAD and took classes on architectural design in high school. This knowledge culminated in what was affectionately called the “Asher House.” From junior until senior year, I worked on the floorplan and design on a small guest house in West Hollywood that needed to be remodeled. Working with a structural engineer, I drew HVAC plans, building site plans, and different elevations and cutaway views.

I’m happy to say that these plans were actually approved by the city of West Hollywood and the house has been built according to these specifications.