We love taking on new and awesome builds, but finding that second part (the “awesome”) of each project is usually the challenge. Looks like [Nathan Seidle] is making awesome the focus of the R&D push he’s driving at Sparkfun. They just put up this safe cracking project which includes a little gamification.
The origin story of the safe itself is excellent. [Nate’s] wife picked it up on Craig’s List cheap since the previous owner had forgotten the combination. We’ve seen enough reddit/imgur threads to not care at all what’s inside of it, but we’re all about cracking the code.
The SparkX (the new rapid prototyping endeavor at Sparkfun) approach was to design an Arduino safe cracking shield. It has a motor driver for spinning the dial and can drive a servo that pulls the lever to open the door. There is a piezo buzzer to indicate success, and the board as a display header labeled but not in use, presumably to show the combination currently under test. We say “presumably” because they’re not publishing all the details until after it’s cracked, a process that will be live streamed starting Wednesday. This will keep us guessing on the use of that INA169 current sensor that plugs into the safecracking shield. There is what appears to be a reflectance sensor above the dial to keep precise track of the spinning dial.
Electrically this is what we’d expect, but mechanically we’re in love with the build. The dial and lever both have 3D printed adapters to interface with the rest of the system. The overall framework is built out of aluminum channel which is affixed to the safe with rare earth magnets — a very slick application of this gear.
The gamification of the project has to do with a pair of $100 giveaways they’re doing for the closest guess on how long it’ll take to crack (we hope it’s a fairly fast cracker) and what the actual combination may be. For now, we want to hear from you on two things. First, what is the role of that current sensor in the circuit? Second, is there a good trick for optimizing a brute force approach like this? We’ve seen mechanical peculiarities of Master locks exploited for fast cracking. But for this, we’re more interested in hearing any mathematical tricks to test likely combinations first. Sound off in the comments below
[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”
Cards you should crank
These greeting cards must be the product of a mechanical engineer run amok. They come with a crank and are designed to entertain with their simple, yet elegant movements. [Thanks Phil]
Magnetic card stripe reader
[JP] built an Arduino based magnetic card reader. It uses off-the-shelf parts but if you don’t mind buying the components this will get you up and running in no time. If you want more info there’s also this Teensy based version.
Homemade Airsoft sentry gun
This sentry gun has an amazingly fast firing rate that can continue for quite a while, thanks to the big flashlight housing that is holds a lot of ammo. [Thanks David]
Scanner easter egg
The engineers over at HP had a little fun building an easter egg into this scanner. If you know what you’re doing you can get it to play the Ode to Joy. It needs to join the old-hardware band from our Links post earlier in the month. [Thanks Googfan]
With exams behind him [Adam Greig] had time to make a Nerf sentry gun. It’s actually quite easy to pull everything together. He’s got a netbook running Motion, an open source motion sensing program for use with a webcam. When movement is detected an Arduino, connected via a USB cable, actuates a servo to pull the trigger of the gun. The turret itself has seen a battery upgrade that increases the firing speed. It’s fun to see hardware prototyping done with a few pencils and a fist full of cable ties. Check it out after the break.
This particular toy, the Nerf N-Strike Vulcan, has become quite a popular starting point for turrent projects. We’ve seen one that uses a motorized base, and another that was part of a final project at Cornell.
Continue reading “Nerf sentry turret”
[John Park] is documenting his build of a Nerf Sentry gun. So far, he’s rigged the trigger and set up the motorized base. He’s documenting the process in fantastic detail with great photos along the way. If you want to see what it will be like when it is finished, check out these other Nerf sentry guns that we’ve featured in the past.
Reader, [Ben Godding], sends in the video for his senior design team’s automated paintball sentry. The frame is made of plasma cut aluminum. The paintball gun uses a custom hopper mounted remotely from the gun body. It has two webcams offering a 160 degree field of vision, and the image processing is done by a dual core pentium CPU booting windows xp off a compact flash card. The computer interfaces with the 1/4scale RC servos using a PIC24. The paintball sentry can either be configured via a computer GUI when a monitor is available or a baclkit keypad and 4×20 charachter display in the field.
Related: [Jared Bouck]’s paintball gun turret
[Jared Bouck] has been sending in his projects for a couple years now. We’ve enjoyed his heavy-duty DDR pads, LCD backlight repair, and ion cooling projects. His latest, an RC paintball gun turret, is our favorite though. He actually rates this as one of the easier projects he’s published; it just took a while to assemble. Several design decisions were made to keep the project simple. Two 32 Degrees Icon-E paintball guns were used. The guns already have electric solenoids for firing, so a special trigger mechanism didn’t have to be fashioned. Q-loaders were used to prevent any ball feed problems. The motors, driver boards, and RC components are all borrowed from combat robots for reliability. He’s hoping to produce a small number of kits based on this design.
Related: We’ve got quite a few sentry gun projects in the archive.