There are a lot of guides out there on how to make your own sentry turret. For some reason they are all being taken down, censored, and/or contain extremely high levels of math, coding, soldering, wiring, parts you can't get, CNC milling, 3D printing, and other various hurdles. Still looking for a good guide but this does seem like something you could do at home. My fav so far is the suit case one. This may be illegal in your area so don't do anything stupid. Real-Life Sentry Guns for Sale - Home DIY Sentry Gun Blasts Intruders With Paintballs Autonomous Sentry Turret
This would be considered a “Set Gun” in most States, and as such it is ILLEGAL to have one Setup, even on your own Property… Before you do set up one of these, you had best check your States Statutes on the subject…
And some individuals place themselves in front of their own gun...with eye opening consequences. The concept of an automatic sentry Turret, is an interesting thought experiment, but in terms of practical installation with anything that is likely to injure an 'intruder'...that may fall foul of relevant legislation, and could place oneself at legal jeopardy. Even installing a 'sub-lethal projectile firing apparatus' may be legally risky. That said, Installing a camera, or remote night vision equipment may be useful for intel collection / surveillance / early warning.
I've seen nerf gun versions and thought they were entertaining, but the taking of a life may only be done defensively when life is in danger and the decision must be made by a human. Even if operated remotely by a human there can be no immediate and justifiable threat to that person. Others, perhaps, but being dislocated also dislocates judgement. Definitely agree on cameras, but cameras are inexpensive enough that unless the tracking systems become reliable, rugged, and inexpensive enough to justify it's easier to run more PoE directly to a PTZ camera. A group of outdoor speakers designed to look like rocks and such (off the shelf, BTW) broadcasting the sounds of everything from twigs snapping to muffled voices and shotguns pumping could be a pretty decent and inexpensive deterrent. That, or a simple alarm. I just like the thought of an intruder having to toss his underwear afterwards.
Besides local customs and statutory laws could you think of any situations where these may be useful. Let us not forget that the second amendment to the constitution allows all Americans the right to use any and all arms... and besides, these are all for paintball, Nerf, and other toys. You guys don't do that?