Thankfully it’s rare that we report on something as tragic as the death of a 17-year old, but the fact that the proximate cause was a 3D printer makes it all the worse and important for us to discuss.
The BBC report tells of a recently concluded coroner’s inquest into the December death of a young man in a fire at his family’s magic shop in Lincolnshire. The building was gutted by the fire, and the victim died of smoke inhalation. The inquest found that he had been working with a 3D printer in the shop and using hairspray to prepare the bed, a tip he apparently picked up from forums and blogs.
Unfortunately for this young man and his family, the online material didn’t mention that hairspray propellant contains volatile hydrocarbons like propane, cyclopropane, n-butane and isobutane — all highly flammable. Apparently the victim used enough hairspray in a small enough space to create an explosive mixture of fuel and air. Neighbors reported a gigantic fireball that consumed the shop, which took 50 firefighters to control.
While the inquest doesn’t directly blame the 3D printer as the source of ignition — which could just as easily have been a spark from a light switch, or a pilot light on a water heater — it does mention that the hot end can reach 300C. And the fact remains that were it not for the 3D printer and the online tips, it’s unlikely that a 17-year old boy would be using enough hairspray in an enclosed space to create what amounted to a bomb.
By all accounts, the victim was a bright and thoughtful kid, and for this to have happened is an unmitigated tragedy for his family and friends. This young man probably had a bright future and stood to contribute to the hacker community but for a brief lapse of judgment. Before anyone starts slinging around the blame in the comments section, think about it — how many time haves you done something like this and gotten away with it? This kid got badly unlucky and paid the ultimate price. Maybe we should make his death worth something by looking at what we do that skates a little too close to the thin edge of the ice.
Continue reading “3D Printer Tragedy Claims a Life”
A striking video appears to demonstrate an explosion via the diesel effect in clear ballistic gel. The diesel effect or “dieseling” refers to when a substance ignites from the effects of pressure, and it’s the operating principle behind the gadgets known as Fire Sticks or Fire Pistons.
Ballistic gel is a broad term referring to a large chunk of dense gel generally used in firearms-related testing to reliably and consistently measure things like bullet deformation, fragmentation, and impact. It’s tough, elastic, and in many ways resembles a gigantic gummi bear. Fans of Mythbusters (or certain DIY railguns) will recognize the stuff. Water-based blocks made with natural gelatin can be easily made at home, but end up with a yellow-brown color and have a limited shelf life due to evaporation. Clear blocks exist that are oil-based and don’t dry out like the water-based ones. It’s one of these that is in the embedded animation below.
Slow motion video capture is a natural companion to just about anything that you’d need ballistic gel for, and good thing — because the video captured what appears to be a diesel effect! The block is hit with a bullet, and as the bullet rapidly expands and dumps its energy into the gel, a cavity expands rapidly. During this process, some of the (oil-based) material in the cavity has been vaporized. After the expanded bullet exits (to the right of the gif above but easier to see in the video below), the cavity in the block begins to collapse. The resulting pressure increase appears to ignite the vaporized material, which explodes with a flash followed by some exhaust.
This effect has been observed in ballistic gel before, but this video shows a particularly clear ignition, followed by a secondary expansion of the cavity, then a flatulent-ish ejection of exhaust as the cavity collapses. If nothing else, it’s a very striking effect clearly captured on film. Slow-motion capture of destructive forces makes visible many things that would otherwise happen too quickly to perceive.
Continue reading “Watch The Diesel Effect in Ballistic Gelatin”
On the morning of September 26th, 2013 the city of Orlando was rocked by an explosion. Buildings shook, windows rattled, and Amtrak service on a nearby track was halted. TV stations broke in with special reports. The dispatched helicopters didn’t find fire and brimstone, but they did find a building with one wall blown out. The building was located at 47 West Jefferson Street. For most this was just another news day, but a few die-hard fans recognized the building as Creative Engineering, home to a different kind of explosion: The Rock-afire Explosion.
The Inventor and His Band of Robots
Many of us have heard of the Rock-afire Explosion, the animatronic band which graced the stage of ShowBiz pizza from 1980 through 1990. For those not in the know, the band was created by the inventor of Whac-A-Mole, [Aaron Fechter], engineer, entrepreneur and owner of Creative Engineering. When ShowBiz pizza sold to Chuck E. Cheese, the Rock-afire Explosion characters were replaced with Chuck E. and friends. Creative Engineering lost its biggest customer. Once over 300 employees, the company was again reduced to just [Aaron]. He owned the building which housed the company, a 38,000 square foot shop and warehouse. Rather than sell the shop and remaining hardware, [Aaron] kept working there alone. Most of the building remained as it had in the 1980’s. Tools placed down by artisans on their last day of work remained, slowly gathering dust.
Continue reading “Experimental Gases, Danger, and The Rock-afire Explosion”
Enjoy your Halloween and be safe. Keep reading for a thermite project preview.
Continue reading “Happy Halloween!”
It’s been a while since there was any advances made in the field if celebratory high-five-ing. [Eli Skipp] just finished her contribution, moving the art forward by adding the sound of explosions to her high-fives. Ignore the audio sync problems in the video after the break to see her Arduino and Wave Shield based offering. It uses a flex sensor to detect a high-five and has a bit of software filtering to avoid misfires when moving your hand or setting it down on a flat surface. It may look a bit ridiculous right now because of the bulk, but we could see a sleeker, cheaper version hitting toy and novelty stores everywhere.
Less useful than a sign-language translating glove, but easier to code and some would say more fun too. Continue reading “Add explosive power to your hi-five”
The iRobot Warrior 710 is shown here touting a new toy called an APOBS or Anti-Personnel Obstacle Breaching System. The system is comprised of an explosive rope pulled by a rocket. We know that sounds pretty awesome, and you can see in the video that it is, in fact, pretty awesome. We don’t condone violence, or war. We do, however, love blowin’ stuff up. This footage was just so pretty, we thought we had to share it. What’s even more amazing is that these guys aren’t battling Apple over the name iRobot.