Building a Sentry Gun with Laser Trip Wire System and Arduino
*NOTE* THIS PROJECT IS DONE BY A GROUP OF STUDENTS FROM SINGAPORE POLYTECHNIC.
Trigger gun when laser is blocked by intruding object.
Tilting is included for expandability but not used in this project.
Things You Need:
Toy Gun(Any will do, preferably a semi-auto)
Continuous Rotation Servo Motor
Servo Arms and Wheels
Copper Strip Board
Light Dependent Resistor
Step 1: Building the Frame
Cut the metal sheets into 6 rectangular pieces(4 of equal length, 1 long, 1 short) and 2 square pieces.
Below are the dimensions we used:
4x 6”(inch) by 2”
1x 10.5” by 2.4”
1x 2.5” by 2.4”
1x 10” by 10”
1x 9” by 9”
Feet(6” by 2”):
Bend the 4 metal piece 90 degrees at the 2” mark and make screw holes(at least 2) at the shorter end.
Base(9” by 9”):
Make screw holes that match your feet’s at 4 corners of the metal piece to mount the feet and a hole in the center for the pivot(the hole size depend the bolt you’re using).
Gun Support(10.5” by 2.4”):
Bend the metal piece 90 degrees at the 2” mark and the 6.5” mark to form a deformed U. Make screw holes(at least 2) at shorter end and 4 holes at the other end to mount your servo.
Turning Panel(10” by 10”):
Make screw holes that match the gun support’s at one corner of the metal piece and one hole in the center for the pivot(should be slightly larger than the pivot but smaller than your ball bearings).
Servo Mount(2.5” by 2.4”):
Make a hole at one end to fit into the pivot and 4 holes at the other end to mount your servo.
Step 2: Trigger of the Gun
Mount one of the servo to trigger the gun
We secure a small servo with a short servo arm onto toygun.
Step 3: Putting Everything Together part 1
Mount the gun onto a continuous rotation servo[Image 1].
Secure it onto the gun support[Image 2 & 3].
Secure another continuous rotation servo with wheels[Image 4] onto the servo mount[Image 5 & 6].
For more detail: Building a Sentry Gun with Laser Trip Wire System and Arduino
We recommend EasyEDA for electronic circuit design.
From Schematic Drawing to PCB Production, Just Need One Tool
Cheap PCB Prototype: 10 pcs 2 layers only $10, quick delivery, 100% E-test