Internship  ·  YC W22

BotBuilt

Factory build and end-effector development at a YC-backed robotic construction startup.

Year 2022
Role Mechanical Engineer
Location Durham, NC
BotBuilt factory with RTUs installed

BotBuilt (YC W22) automates residential wood framing using robotic arms. I joined as the sole mechanical intern for the second factory buildout and end-effector development, both on aggressive timelines.

Led mechanical buildout for two months at peak 70-hour weeks. Responsible for 500+ 3D-printed parts, 100 sheet metal parts, RTU installations, pneumatic line runs, and wiring throughout the facility. Self-taught MIG and stick welding on-site.

Factory buildout in progress
Factory buildout in progress
Wiring and pneumatics
Pneumatic and wiring runs
Control panel
Control panel assembly
MIG welding
MIG welding — self-taught on site
Welded posts in use
Welded structural posts installed

Designed and built an autonomous test fixture to validate end-effector performance and surface mechanical failure modes before they appeared on the robot. The fixture enabled structured root-cause analysis across 5 design iterations, improving reliability on an aggressive production timeline.

Details and imagery withheld under NDA.

Robot cameras fouled with wood dust mid-run. Started with electronic fan + 6 nozzle iterations (paper cone, cardboard, three 3D-printed variants). None produced sufficient airflow at the camera face.

Reworked the pneumatic circuit to free a solenoid port. Prototyped a perforated pneumatic line with hot-glue washers: confirmed it worked, then CAD'd and 3D-printed a final ring-shaped diffuser. Mounted on the robot; in production use.

Paper cone nozzle prototype
Iteration 1 — paper cone
3D printed nozzle variants
3D-printed nozzle variants
Final pneumatic design — works first try
500+
3D-printed parts
5
End-effector design changes
6
Camera nozzle iterations

Factory operational on an aggressive timeline. End-effector reliability improved through structured root-cause analysis and 5 design changes. Camera cleaning device deployed and still in production use.