A DIY airsoft sentry gun build detailed
Remote weapons stations and autonomous sentry guns are a fact of modern warfare in the 21st Century and, if running an advanced MILSIM deserved to be added to your range if possible. One hobbyist has figured out how to craft his own and has shared the love with the world.
The real thing
The U.S. military as well as others have remote weapons stations and have been using them in combat for a generation. Perhaps the best known are the M101 CROWS and later M153 CROWS II mounts, with more than 10,000 purchased by the Pentagon since 2004 to replace manned machine gun/grenade launcher mounts on the top of MRAPs, Hummers, tanks, Stryker's and other vehicles. The gunner who is all safely buttoned up behind armor under the system and watches everything via video feed, which is much better in the end, controls these mounts. After all, if a sniper shoots up a remote control mount, the taxpayers suffer the loss rather than a young soldier, sailor, airman or Marine.
Then there are completely unmanned "sentry guns," which are more controversial.
Currently the U.N.'s Convention on Certain Conventional Weapons (CCW), signed by 117 member states regulates five different classes of weapons deemed excessively inhumane including mines, blinding laser weapons, and explosives with non-detectable fragments and has been weighing the addition of lethal autonomous weapons systems (LAWS) to the list.
Although Terminator-style "killer robots" are not currently in the arsenals of the world, there are a number of LAWS systems fielded. These include the static http://www.cnet.com/news/korean-machine-gun-robots-start-dmz-duty/ $200,000 Samsung SGR-A1 "sentry bot" turrets installed along the Demilitarized Zone between North and South Korea as well as stretches of Israel's border.
These stationary systems can be armed with either a 5.56mm light machine gun or 40mm low-power grenade launcher and are normally under human control but can be programmed to make autonomous decisions if unmanned.
However, both of these types could be role-played in an airsoft simulation with the type of device detailed below.
An online collaboration, Project Sentry Gun has in the past several years been a hub of information where individuals have shared their DIY builds to include paintball and airsoft guns.
YouTuber Austiwawa a few weeks back posted a video of his home build autonomous "killer robot" style sentry gun. He used a tripod music stand, some MDF, a set of casters, a Y-axis servo with two high torque servos on a lazy susan style set up and a box of screws. The gun is a rather cheesy gravity fed battery-electric HK. He goes on to make the gun electrically fired by remote with some wire and soldering iron. The only moderately hard part is making the circuit board with an Arduino Uno microcontroller board, some resistors, a diode, a transistor and downloading the open-sourced software (off Project Sentry Gun).
The sentry gun is tied to a webcam to cue to its target.
In all, provided you have the basic electrical skills, you can add an airsoft sentry gun to your field with a budget of less than $200, especially if you already have a gun you want to dedicate to it or some parts (servos, etc.) laying around. (Disclaimer: Of course, obey all local, state and federal laws and if you are not an adult get the help of one, etc.)
Without further, the vid: