Sentrifying A Nerf Gun


[Brittliv] made the mistake of getting her friends into Nerf weaponry, and so began the race to mutually secured destruction via foam darts. She may have the upper hand in this war, because her Nerf Vulcan sentry gun is both incredibly powerful and is able to be operated autonomously with a webcam featuring a friend or foe identification system.

The azimuth and elevation mount for the gun is made out of plywood, with each axis controlled by a single servo attached to an Arduino. Of course a stock Nerf gun would be fairly boring, so [BrittLiv] increased both the voltage going to the gun’s motor and the strength of the gun by replacing a 2kg spring with a 5kg spring.

Targets are tracked with a webcam using Processing and a bit of code from Project Sentry Gun. One interesting feature is a friend or foe tracking system; if the gun sees someone wearing a t-shirt with the Instructables logo, the target is identified as a friend and is not brutally mowed down with plastic darts.

34 thoughts on “Sentrifying A Nerf Gun

    1. Shame we didn’t see the gun actually firing automatically. I’d be interesed in seeing if it fired on friends before it’d identified them.

      Smoking hot too boot.

  1. very well done! I have a lot to learn from this project. Cant help but feel like it is too easy to modify this to be a horrible and anonymous killing machine complete readily available how to build instructions….. but i guess that’s the world we’re living in/heading towards….. hrmmmm… honestly, Im not a fan DIY killing machines….. and this is suggestive enough to make me ponder a fucked up future.

    1. Just replace the NERF with a pair of drum fed ar-15’s. except it will flop over after the first shot. real recoil dampening is a lot harder on real weapon platforms. So no, it will not be “easily” converted.

    2. The fact is that hobbyists with similar projects have already been turned into defense contractors, e.g. US Mechatronics. This project not only proves that this is a relatively trivial project (imagine what an experienced defense contractor can do with a few billion dollars and several years) but also provides the how-to to The People, who need it most. To those naysayers who claim that it cannot be converted easily, pish and tosh. Build it a lot sturdier, and shock-mount it to a fixed point with poly bushings, which will outlast you.

  2. As someone who is addicted to airsoft, I want to replicate this. However, I’m thinking about using an IR LED for friend/foe detection. Then place it in the dark area of my preferred indoor CQB field..

  3. Want! definitely want.
    But those servos seem pretty underpowered if you consider how much the gun sways when the movement stops. Brushless motors may be an alternative, though more expensive.

  4. Seeing as the instructables logo is presumably on only one side of the shirt (I haven’t checked out the build yet), wouldn’t say, a coloured arm band be a bit more practical as that can be identified from all angles?

  5. Nice build, I like it. Love Nerf stuff too, and air soft. Actually, just about any guns.
    Any time I go shooting before I go to the doctor, they notice my blood pressure is a bit lower.

  6. What the fuck is going on in here? did the liberals not have anything else to do today?

    You people and your speculative talk are what is wrong with this country.

    You know this is nothing more than some clever engineering by an amateur having fun with a NERF gun right?

    You know you can purchase a turret that shoots NERF online for a few dollars right?

    And YES, it might be possible to convert it into a lethal weapon IF IT WERE COMPLETELY REDESIGNED.

    This is a plastic toy. Not a firearm. Get over it obamazombies.

    1. Oh, you Troll you… Immediately labeling people by the only means you know, their political affiliation. The simplistic nature of your mind too limited to conceive of anything beyond your country, or even of your specific ideals.

      As a left-leaning engineer, I raise the same argument against the triviality of converting this toy into a killing machine… but my political affiliation has nothing to do with my argument. Please go read some books.

    2. And this is why americans have shootings in there schools. “What you want to control guns, oh you must be evil. We need guns so we can protect our selfs from other people with guns” :/

    3. What is it about guns that makes people go completely retarded?

      1. “Oh no this system could be adapted to fire real guns” yeah so can my fucking hands. Any sort of evildoing conceivable that could be done with an auto sentry would be more easily done by a guy holding a gun. This is true for both whacky jihadists and for regular military. Not to mention anyone with the knowhow to make a version of this contraption that can actually hit jack shit at a distance doesn’t need this article.

      2. “leave it to LIBERALS to be scared of this”/”as a left leaning engineer, I raise the same argument…” liberal and left are not synonyms. Nor are Democrat and liberal, nor Republican and conservative. Turning everything into a Republican/right/conservative vs Democrat/left/liberal false dichotomy is the hallmark of the American political illiterati.

    4. Politics? I love when people throw politics into the mix (sarcasm)… I’m a liberal, I own and support firearm rights. But I’m a pacifist (believe in target shooting only)… I’m also a bit of a tinkerer when it comes to making computers work (IT)..

      Her Turrent design has nothing to do with real firearms as its just a toy. Besides.. If you’re that terrified of it I hate to tell you to go and google this.. Now be a good little troll and return to your underground cement bunker from whence you came eh?

      1. …if anyone is confused, I’m not trying to call him names, “fartface” is the name of the person who usually posts this sort of obnoxious rant. I was surprised to see a different name at the top.

  7. Great write up. For all the naysayers, this would not be hard to convert to real weaponry. An AR-15 shoots as fast as you can pull the trigger, and is easily modified for a solenoid system. Better yet, 2 10-22 rifles with easily purchased 50 round magazines would solve the recoil problem and they are easily disassembled from the stock and remounted. The hard part is the tracking system and the engineer on this project has solved that. Simple matter to convert these for sentry duty. I could see this project coming up on Doomsday Preppers on TLC.

  8. Wow, this whole thread is pretty fucking retarded. I only came in here to deride the use of the Vulcan for this task. Small plunger tube, weak spring, crappy chain advance mechanism…. A better choice would have been the Buzzbee Overlord if you want the chain, or the Nerf Stampede or forthcoming Rapidstrike if clips are okay.

      1. Yeah, I read the article. The design of the internal advance mechanism and also the motorized priming mechanism have both shown to be weak. Adding a stronger spring will help individual shot performance, but at the cost of short life and slow firing repetition. Increasing the system voltage can speed up the repetition and also allow priming of even heavier springs in the plunger, but the motor is rather light duty and will burn out quickly with anything over approximately 12 volts. 14.4V will smoke it in a hurry. Beyond all of this, the chain makes for a very short effective barrel, limiting the amount of energy transfer from the plunger to the dart. Regardless of any other upgrades performed, the chain limits range to about seventy feet.

    1. No, your comment is “retarded.” The Buzzbee Overlord? Nice try Buzzbee sales guy – that thing looks about as cheap as something you’d find in the Walgreen’s toy section, and about as threatening looking as any toy made by Fisher Price. And the Stampede doesn’t use belt fed ammo.

      1. First off, let me congratulate you on your keen grasp of the English language. I was suggesting the Overlord if chains were desired, but the Stampede or Rapistrike if clips/drums were acceptable. Second, I am no salesman. Anyone in the Nerf community will recognize me as an automotive technician and engineering student. I have an extensive collection of various Nerf, Buzzbee, and Lanard blasters, including two Vulcans, four Stampedes, and a single Overlord. Between the two belt-fed blasters, the Overlord performs better out of the box, is less expensive, substantially easier to upgrade, less complicated, lighter, and is actually still available at retail. The design may not be “menacing”, but let us face reality here… They are both toys. You may be surprised to find that the build quality of the Buzzbee blasters easily matches that of the Hasbro products. Many of their designs are much for fun to use, and more creative to boot.

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