MRRF: Mostly Harmless 3D Printed Arms

The Midwest RepRap Festival isn’t just people hanging out with their 3D printers all weekend; There are also people bringing all the things they made with their 3D printers. There was an R2D2 and half of a B1 Battle Droid, a 3D printed quadcopter and of course 3D printed weaponry. [Ryan] and [Kane] from Mostly Harmless Arms brought a collection of their totally not trademark infringing not-Nerf guns.

The guys have a few designs for guns that shoot silicone-tipped extruded foam darts much further than a Nerf gun. There’s a bow, a more traditional spring-powered blaster, and a crossbow. All the designs with the exception of a few pipes and tubes and springs are 3D printed, and all the parts are small enough to fit on an 8″ bed. The darts are made with a dome mold for silicon and insulation foam that’s normally wedged in window and door frames. They’re dusted with cornstarch to prevent sticking, although in the video below there were a few jams. That’s to be expected; there was a camera around.

Continue reading “MRRF: Mostly Harmless 3D Printed Arms”

Supersonic NERF Dart Speedometer

ATtiny Chronograph

[John] was faced with an interesting problem: after he built his own air cannon, how could he tell exactly how fast his NERF darts were moving? Luckily he had some spare parts on hand and hacked together a fully functional projectile speedometer for less than the cost of an Arduino.

A device is essentially two detectors spaced a precise distance apart from one another. When something passes the first detector, a timer is activated which measures how long it takes the object to reach the second detector. From this, the device calculates the speed. [John] used infrared emitter/detector pairs spaced exactly three inches apart and wired them to an ATtiny2313. After a little bit of coding, he now knows just how fast he can fire those squishy ballistic missiles.

The infrared emitter/detector pairs are mounted to a PVC pipe through which the projectile travels. [John] notes that in theory this could be used to measure almost anything that could fit through the pipe, although this particular device might be damaged by muzzle flash or a pressure wave from an actual gun.

We’ve seen other NERF dart air cannons before, and we wonder if maybe there should be some sort of competition to see who can shoot a NERF dart the fastest now that there’s an easy way to measure speed?

 

Reactive target range for Nerf, Airsoft, etc.

reactive-target-range

Taking the time to build a reactive target range really adds to the fun of toy weapons. It lets you move beyond just point and shoot to actual games of skill.

The project is anchored by an Arduino board. It connects to a piezo element on the back of each of these sheet metal targets. Detecting when a projectile hits the target works pretty much the exact same way the ever popular Knock-block works. To provide interactive enjoyment each target has an LED which, when lit, indicates that the target is active. From here it’s just a matter of coding to add different challenges. So far [Viktor Criterion] has implemented quick draw, timed, and rapid fire modes. The demo after the break shows off everything, including the slick modular design he came up with to make the system portable.

We’d love to see these targets mounted on motorized tracks. Each round would have the targets moving closer to you at a faster pace to keep you on your toes.

Continue reading “Reactive target range for Nerf, Airsoft, etc.”

Sentrifying a Nerf gun

vulcan

[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.

Continue reading “Sentrifying a Nerf gun”

Nerf Sentry Gun for the Apocalypse

nerf-sentry

If you’ve ever wanted to shoot someone with a Nerf gun, but just didn’t have the energy to get off the couch, this hack may be for you. It’s also a good way to ward off zombies if another apocalypse, Mayan or otherwise, is on the horizon.

Although the effects are very cool, as seen in the video after the break, the method for making this setup was quite simple. The requirements for this project were that the gun could not be permanently modified, and everything had to fire automatically. These restrictions may have contributed to the simplicity of the design as many of us would start breaking things before we had to.

Instead of some elaborate hack, the trigger was tied back in the firing position at all times. A relay was then used to interrupt the power supply to the mechanism allowing an Arduino equipped with an infrared sensor to automatically control the firing. The setup is explained after the break, but skip to around 1:55 if you’d rather just see the guns in action. Continue reading “Nerf Sentry Gun for the Apocalypse”

Hackaday Links: November 4, 2012

Wait, you’re using a Dremel to cut PCBs?

Cutting copper-clad board or – horrors – depanelizing PCBs is a pain if you don’t have the right tool. Over at Hub City Labs they’re using a small, cheap metal shear & break. Bonus: it can cut and bend sheet metal, so the Hub City folks can also make enclosures.

Color Codes? Yes, Color Codes.

[Joe] sent in a cool utility he whipped up called resisto.rs. Plug in a resistor value, and it’ll spit out the 4-band, 5-band, and surface mount labels for that resistor value. Pretty neat.

Parallel Ports

Parallel ports may be a dying breed, but that didn’t stop [Electroalek] from putting together a VU meter that connects to his LPT port. It’s an extremely simple design; just connect some LEDs and resistors to the pins of a parallel port, and you can easily control them via software on a computer. Playing around with an LPT port used to be common knowledge, so we’re glad to see [Electroalek]’s work here.

The power is out, but Radio Shack is still open

[Jason] is stuck in New Jersey without power and needed a way to charge his phone. He whipped up a cell phone charger using an RC car battery and an LM317 voltage regulator. It’s an easy circuit to piece together, and judging from [Jason]’s picture will hopefully keep his cell phone charged until the power comes back on.

Shooting 50 Nerf darts all at once

If [Rob]’s project log is to be believed, it looks like they’re having a lot of fun over in the Sparkfun warehouse. They decided to have a full-scale Nerf gun war for a summer intern’s last day. [Rob] came up with a DIY Nerf shotgun that shoots 50 darts across the room, just waiting to be found sometime in the next decade.

There’s a great video of [Rob] firing the single barrel (yeah, they made a trident-shaped one as well) gun at well prepared but unsuspecting coworkers. Be sure to check out the comments of this post to see Hackaday readers frothing at the mouth because PVC pipe isn’t a pressure vessel guys. You’ll all surely die.

How to build an extremely powerful nerf gun

[TopCityGear] was trying out a piece of PVC as a blow gun barrel when he thought he’d try to give it a little more power than what his lungs could put out. What he came up with is this air-powered Nerf gun that definitely leaves a mark. The video after the break is a show-and-tell, a build log, and finally a demonstration of its power. He adds a nail to a Nerf dart and drives it through a board, then leaves a huge welt on his poor friends chest with a plain old foam dart. It reminds us of those riot guns that shoot bean bags.

The air is stored in that twelve-inch PVC reservoir. On the rear cap there’s a Schrader valve for pressurizing the tank with a compressor or even a bike pump. The grip is a gutted cordless drill whose battery doubles as the power source for the electric sprinkler valve which fires the gun. The screw fitting just in front of the hand grip lets him remove the barrel so that the projectile can be inserted.

This reminds us of that gun which shoots water-filled ping-pong balls.

Continue reading “How to build an extremely powerful nerf gun”