Harvard Digital Fabrication

PHYS-S-12 at Harvard Summer School: eleven weeks covering laser cutting, CNC milling, casting, microcontroller programming, embedded sensor integration, and machine building, culminating in a modular TVC rocket. Each week is documented with build notes, CAD files, and process photos. The full course site, including week-by-week writeups and the final project breakdown, is embedded below.

Complete a full fabrication curriculum covering CAD, laser, CNC, casting, electronics, and embedded systems, culminating in an integrated final project under real time pressure.

• Weekly scope limits. Each domain had to be understood fast enough to produce a result.
• Chemical propulsion was safety-prohibited. TVC project pivoted to electronics-based stabilization.
• Limited equipment access required adapting designs to whatever machines were available on the day

• TVC gimbal used PLA's inherent flexibility as the compliant hinge mechanism. Eliminates the backlash you get from traditional linkages.
• Twist-fit modular rocket sections for field assembly without tools
• MPU-6050 IMU mounted at rocket base with OLED display for real-time orientation readout during bench testing

1. 01

   Week 2: Laser-cut press-fit cardboard assembly. Kerf compensation was the key lesson.

2. 02

   Week 3–4: Kinematic sculpture with gear-reduced DC motor and Arduino Uno, later upgraded with herringbone gears from Fusion 360 spur gear add-in

3. 03

   Week 5: TVC mount prototyped on Prusa. First version failed on fit, second version used Polycam photogrammetry for reference geometry.

4. 04

   Week 6: MPU-6050 6-axis IMU calibrated against angle finder, compliant mechanism contact sensor designed for launch detection

5. 05

   Week 7: OLED display on I2C showing live gyro data, oscilloscope characterization of output timing

6. 06

   Week 8: Roland SRM-20 CNC milling in machinable wax. First attempt failed when wax melted onto the end mill due to speed. Surface roughing fixed the adhesion issue.

7. 07

   Week 9: ESP32 ESPnow peer-to-peer communication, both boards exchanging data via MAC address registration

8. 08

   Final: Modular TVC rocket, Bambu Lab 3D printer for final parts, collaborative build with Hiranya

• CNC setup parameters matter more than the geometry. Losing a wax mold to a spindle speed error is an expensive lesson.
• Photogrammetry (Polycam) outperformed the dedicated scanning hardware (RevoPoint) for complex organic geometry
• Modular assembly needs to account for cumulative tolerance. A twist-fit that works at the bench can bind in the field.