In the 1950’s and 60’s, the world had rocket fever. Humankind was taking its first steps into space and had sights on the moon. Kids could build rockets at the kitchen table and launch them in the schoolyard. On the darker side, the arms race was well underway with the US and USSR trying to close the fictional missile gap.
All around the world, engineers were trying to do new things with rockets. Among these were Robert Mainhardt and Arthur T. Biehl, who thought rockets could be useful as small arms. Together they formed MBA (short for Mainhardt and Biehl Associates), with an eye toward future weapons – – specifically rocket bullets.
Continue reading “Rocket Bullets: The Flame and Fizzle of the Gyrojet”
What do you do when you have time, thousands of dollars worth of magnets, and you love Mythbusters? Science. At least, science with a flair for the dramatics. The myth that a magnetic wristwatch with today’s technology can stop, or even redirect, a bullet is firmly busted. The crew at [K&J Magnetics] wanted to take their own stab at the myth and they took liberties.
Despite the results of the show, a single magnet was able to measurably alter the path of a projectile. This won’t evolve into any life-saving technology because the gun is replaced with an underpowered BB gun shooting a steel BB. The original myth assumes a firearm shooting lead at full speed. This shouldn’t come as any surprise but it does tell us how far the parameters have to be perverted to magnetically steer a bullet. The blog goes over all the necessary compromises they had to endure in order to curve a bullet magnetically and their results video can be seen below the break.
Here we talk about shooting airplane guns so they don’t get mislead after leaving the barrel, and some more fun weaponry from minds under Churchill’s discretion.
Continue reading “Coming Back to Curving Bullets”
Have some .40 cal shell casings sitting around with nothing to do? How about some bullet earbuds? If you’ve ever wondered about the DIY community over at imgur, the top comment, by a large margin, is, “All of these tools would cost so much more than just buying the headphones”
Here’s something [Lewin] sent in. It’s a USB cable, with a type A connector on one end, and a type A connector on the other end. There is no circuitry anywhere in this cable. This is prohibited by the USB Implementors Forum, so if you have any idea what this thing is for, drop a note in the comments.
Attention interesting people in Boston. There’s a lecture series this Tuesday on Artificial Consciousness and Revolutionizing Medical Device Design. This is part two in a series that Hackaday writer [Gregory L. Charvat] has been working with. Talks include mixed signal ASIC design, and artificial consciousness as a state of matter. Free event, open bar, and you get to meet (other) interesting people.
Ghostbusters. It’s the 30th anniversary, and to celebrate the event [Luca] is making a custom collectors edition with the BluRay and something very special: the Lego ECTO-1.
Let’s say you need to store the number of days in each month in a program somewhere. You could look it up in the Time Zone Database, but that’s far too easy. How about a lookup table, or just a freakin’ array with 12 entries? What is this, amateur hour? No, the proper way of remembering the number of days in each month is some bizarre piece-wise function. It is: f(x) = 28 + (x + ⌊x⁄8⌋) mod 2 + 2 mod x + 2 ⌊1⁄x⌋. At least the comments are interesting.
Arduinos were sold in the 70s! Shocking, yes, but don’t worry, time travel was involved. Here’s a still from Predestination, in theatres Jan 9, rated R, hail corporate.
Here’s an image of a bullet’s path to the target. There’s a couple of things to note. First of all, this is not a tracer round, the projectile actually has an LED incorporated which was picked up as a trail in the long (relative to bullet speed) exposure. The second – and most obvious – thing to consider is the non-liner path it took to its objective. That’s because this is a laser guided bullet.
The smart bullet is a about four inches long and carries with it a light sensor, 8-bit processor, and some electromagnetic actuators. The tip is searching for a laser-painted target, with an algorithm calculating course corrections along the way and using the actuators to move fins which alter its path. For us the most interesting part is that this ammo requires a non-rifled barrel. The rifling spins the bullet as it leaves the firearm, which usually results in a straighter and more dependable path. But the microcontroller wouldn’t be able reliably steer if it were spinning.
We’d bet this ends up as a special sniper tool in video games before we hear about it on the battlefield. Check out a clip of the dart-like bullet leaving the muzzle in the clip after the break.
Continue reading “Last century’s guided missile steps aside for this guided bullet”
Did you know that a standard camera flash is much too slow to capture high quality images of bullets? A relatively long flash duration results in blurred images of the bullet. By building this air gap flash a bullet can be frozen in mid-air, producing some stunning results. There is an element of danger here, and not from the bullet. This flash uses a 35,000 volt capacitor to produce the mini-bolt of lightning which serves as the light source. The unit can be built for a few hundred dollars, which sounds like a heck of a deal if commercial models really do start at $8k and go up from there.
Now that the photographer has a super-fast flash, a camera axe takes care of the timing… which is everything.
[Mike] built a sensor rig to measure projectile speed. The setup uses a tunnel with two sensors in it. Each consists of a laser diode on one side focused on a photodiode in the other. The two are monitored by an op amp and measured by an ATmega128 microcontroller. When the beams are broken the elapsed time between the two events is measured in order to calculate speed. There is a setting to adjust the calibration for a range of speeds, which came in quite handy as [Mike] initially tested the device with rubber bands before moving on to a pellet gun and then a rifle.
It seems like he’s tempting fate by shooting a target just a few inches below his exposed circuitry but his marksmanship prevailed. We’ve seen bullet speed detectors in the past, used just for the delight of seeing how fast the projectile is moving, and also to capture an impact at just the right instant.
Sometimes it’s amazing how slow our sense of time is. We find [Maurice’s] bullet capture system a great example of this. A pair of IR sensors spaced two inches apart can capture and calculate the speed of a projectile. Couple this with a user-input distance from the sensor to the target and a microcontroller can extrapolate the exact moment to trigger a camera to catch a bullet in mid-air.
As with his other projects, all the details on how to build and use this system are available for your perusal.