Project Sentry Gun: Build Your Own Autonomous Tracking Turret
Over a decade ago, I built my first sentry using a laser pointer and a bunch of 3D-printed parts. It was a fun weekend project that sparked something bigger. Today, Project Sentry Gun is one of the most complete, open-source autonomous targeting systems available.
Important Build Notes (Please Read)
Before diving in, here’s a critical tip that isn’t covered in every guide:
Do not use a GoPro or any camera with a rounded wide-angle (fisheye) lens. The distortion at the edges of the frame will throw off your aiming calibration. While the center of the view can be calibrated accurately, moving targets near the edges will be misaimed. Stick with a standard webcam with minimal distortion for best results.
Welcome to Project Sentry Gun
Project Sentry Gun is home to one of the most versatile, fully open-source sentry gun systems on the web. Our system autonomously detects, tracks, aims, and fires at targets using:
- An airsoft or paintball gun
- A standard webcam for target detection
- A computer to process the video feed in real time
- Servo motors for precise aiming and trigger control
- A custom controller board to bridge the computer and hardware
What makes us unique is our commitment to complete openness. Everything is open-source:
- 100% of the code
- Full electrical schematics
- CAD design files for the Standalone Controller
The project has been built and deployed on six continents and in more than 20 countries — it’s even used by the Australian Navy in their training programs.
Want to Build Your Own?
You’re in the right place. Everything you need is freely available:
- Complete step-by-step build guide
- Full source code (free and open-source)
- Electrical diagrams and CAD files
- Active community forum with builds, troubleshooting, improvements, and ideas from other makers
Hundreds of people have successfully built their own sentry guns using this system. Whether you’re a hobbyist, educator, or just love robotics and computer vision, this project offers a rewarding challenge.
Resources
- GitHub Repository: https://github.com/sentryGun53/Project-Sentry-Gun
- Original project site (archived): [Internet Archive link]
- (http://www.instructables.com/id/Nerf-Vulcan-Sentry-Gun/)
Check out the build guide first, then explore the forum to see what others have created — from simple laser pointers to full-motion paintball sentries.
Have fun, stay safe, and happy building!
Want to build your own?
You're in luck! All the help and information you will need is here, and the software is free and open-source. Lots of people have already used this system in their own sentry guns, with successful results. Check out the links on the left side of this page for all the resources you will need, including a step-by-step guide to the entire build process. After that, check out the forum to see others' completed sentry guns, sentries in progress, ideas and improvements, and FAQ's.
there are several newer open-source sentry/turret projects, though none seem to have the same level of polish, documentation, and longevity as the original Project Sentry Gun (which dates back to ~2010–2014). Most modern alternatives leverage Raspberry Pi + OpenCV (or more advanced AI like YOLO), which offers better performance than the old Processing + Arduino setup.
Notable Newer / Modern Alternatives
| Project | Platform | Key Features | Year (approx.) | Link |
|---|---|---|---|---|
| Shooty | Raspberry Pi + OpenCV (Python) | Autonomous paintball/airsoft/Nerf turret, motion tracking | ~2020s | github.com/xoxota99/shooty |
| Hacker Shack Tracking Turret | Raspberry Pi 3 | Motion tracking, autonomous + manual modes, well-documented | 2016–2017 | github.com/HackerHouseYT/Tracking-Turret |
| Automated Airsoft Turret (norton-chris) | Raspberry Pi 4 + Coral TPU + LIDAR | Advanced tracking (camera + LIDAR), aimed at wildlife | Recent | Search GitHub for norton-chris/Automated-Airsoft-Turret |
| AI-Powered Turrets (various) | Raspberry Pi / other | YOLO / modern object detection, face/pose tracking | 2023–2025 | GitHub topics: "turret" + YOLO |
Key Trends in Newer Projects
- Raspberry Pi dominance — Easier all-in-one processing (no separate laptop needed).
- Better computer vision — OpenCV for basic motion, or YOLO models for object/person detection.
- Hardware upgrades — Stepper motors, LIDAR for distance, Coral TPU/Google Edge TPU for faster AI inference.
- Use cases — Fun builds, garden pest control (pigeons, geese, cats), cosplay/Portal-style turrets, or office pranks.
There are also many one-off Instructables, Hackaday.io, and YouTube builds (e.g., AI water gun turrets for pigeons or Portal replicas from late 2024).
Comparison to Original Project Sentry Gun
- Original — Very complete docs, forum, CAD files, controller board, proven across many countries.
- Newer ones — Often simpler or more experimental. They benefit from modern hardware (cheaper, more powerful SBCs) and libraries, but may lack the same depth of community/support.
Recommendation: If you liked the original, start with Shooty or the Hacker Shack project for a modern refresh — they’re easier to adapt with 3D-printed parts and current webcams.
