Ask Hackaday: Open Fire Suppression And Safety Standards

April 12, 2016 by 74 Comments

We posted about a 3D printer fire a while back. An attendee of the Midwest RepRap Fest had left his printer alone only to find its immolated remains on his return. In the spirit of open source, naturally, he shared his experience with the rest of us. It occurred to me that hackers are never powerless and there are active things to be done and avenues to explore.

An animation of a commercial fires suppression system, fire trace's, operation. http://www.firetrace.com/fire-suppression-systems/direct-release-systems/
An animation of a commercial fires suppression system, fire trace’s, operation. Firetrace‘s website has more.

There are really fantastic commercial fire extinguishing systems out there. One implementation, which is commonly deployed in cabinets and machining centers, is a plastic tube pressurized with an extinguishing agent by a connected tank. When a fire breaks out the tube melts at the hottest locations, automatically spraying the area with a suppressant. Variations of this involve a metal nozzle filled with a wax or plastic blended to melt at a certain temperature, much like the overhead fire sprinklers.

This system is also used inside engine compartments with success. For example, this item on amazon, is nothing but a pressurized plastic tube with a gauge on one end. Since the inside of an engine compartment can be treated as an enclosed space, very little fire suppressant is needed to extinguish an unexpected flame. It is important to note that this system works in a high temperature environment like an engine compartment, which bodes well for enclosed build envelopes on 3D printers.

BlazeCut Automatic Fire Suppression System 6' TV200FA, Automotive Extinguisher
BlazeCut Automatic Fire Suppression System 6′ TV200FA, Automotive Extinguisher Installed under Car Hood.

Another option is to construct a suppressant mine. A Japanese and a Thai company have both come out with a throwable fire extinguisher. In the Japanese device, the outside of the extinguisher is a breakable glass vial which shatters upon impact; releasing the agent. The Thai device looks like a volley ball, and releases the agent upon the application of heat. This device seems like a better candidate for 3D printing or home projects. Imagine a small rectangular pack with adhesive on one side that sits near the possible fire points of the printer, such as under the bed or above the nozzle. In the event of a fire, the casing will melt and the system will automatically deploy a spray of extinguishing agent.

Most of the chemicals used in these constructions are benign and readily available. High pressure tubing and waxes can all be purchased and the desired melt points can be aligned with their datasheets by need. Plastic sheets are not hard to procure. These offer a nice solution due to their entirely passive nature. They don’t need power to operate and rely entirely on the properties of the materials they are constructed out of.

There are other options in active systems. Hackaday readers suggested things such as flame sensors for adding automatic cut-offs in case of a fire. Thermal fuses can also be considered in some cases. There are other tricks too, which are less kosher but will work nonetheless. For example, placing a critical wire, fuse, or component in the likely path of a fire so that it is destroyed first, stopping the operation of the device quickly. These avenues should be explored. At minimum there should be at least one project that uses a Raspberry Pi and an Arduino to tweet that fire suppression failed and the house is on fire.

fire-extinguishing-balls
The Thai invention is a volleyball that melts upon contact with flame and releases a pressurized extinguishing agent.

Some of the big questions to ask are on the legal and ethical side. If someone started selling kits for a DIY fire suppression system and a fire ends up destroying someone’s property despite the device, who is responsible? Is it even safe to post instructions? What if a kit prematurely sets off and injures someone. I imagine a big part of the cost of these professional systems is some sort of liability insurance and certification. Still, putting a six hundred dollar fire suppression system on a six hundred dollar printer seems silly, and something is better than nothing.

Lastly, the comments directed a ton of flak towards the certification systems. There should be no reason that open source projects can’t produce their own specification for safety. An open source specification without an agency naturally couldn’t provide a legal defense against property damage, but a thought-out test program would provide piece of mind. For example, in the case of 3D printers, one could have a set of basic fail-safe tests. One example would be bringing the printer up to temperature and rapidly disconnecting the thermistor, does the printer erupt into fire? No? Good, it meets the spec. I wouldn’t mind knowing that the latest version of Marlin was tested on the popular boards and still met the community specification for fire safety.

As far as I can tell, there’s been very little work in open sourcing safety systems or in providing a testing framework for ensuring open hardware meets basic safety conditions. Many of you have experience with these systems. Some of you have gone through the entirely un-enjoyable process of getting a UL certification. What does Hackaday think?

Arduino Comes To The Raspberry Pi, Linux ARM Devices

April 12, 2016 by 67 Comments

Arduino is the perfect introduction to microcontrollers and electronics. The recent trend of powerful, cheap, ARM-based single board Linux computers is the perfect introduction to computer science, programming, and general Linux wizardry. Until now, though, Arduino and these tiny ARM computers have been in two different worlds. Now, finally, there are nightly builds of Arduino IDE on the Raspberry Pi and other single board Linux computers.

The latest Arduino build for ARM Linux popped up on the arduino.cc downloads page early this week. This is the result of an incredible amount of work from dozens of open source developers across the Arduino project. Now, with just a simple download and typing ‘install’ into a terminal, the Arduino IDE is available on just about every single board Linux computer without having to build the IDE from source. Of course, Arduino has been available on the Raspberry Pi for a very long time with sudo apt-get install arduino, but this was an older version that cannot work with newer Arduino boards.

Is this distribution of the Arduino IDE the same you would find on OS X and Windows? Yep, everything is the same:

While this is really just arduino.cc improving their automated build process and putting a link up on their downloads page, it does make it exceptionally easy for anyone to set up a high school electronics lab. The Raspberry Pi is almost a disposable computing device, and combining it with Arduino makes for a great portable electronics lab.

Hackaday World Create Day: The Hackaday Event In Your Town

April 12, 2016 by 1 Comment

Not too long ago we announced the Hackaday Meetups. We were hoping at least a few dozen people would be excited to host a meetup in their town. What we got was hundreds of people and we couldn’t be happier about it.

If you are excited about Hackaday and you want to meet other community members in your area this is your chance. We have streamlined the process so that you don’t need to wait for us to start setting up your meetup. Here’s how you do it:

  1. Submit this form
  2. Set up your event here: https://hackaday.io/event/add
  3. Here’s a template page with details you can use to create your own
  4. You can use graphics from this link or upload graphics of your own

The first global event is on Saturday, April 23rd: Hackaday World Create Day. Get together and get to know the other community members in your area. Brainstorm a project and document it the concept as a Hackaday Prize entry. Many groups have already added other activities that day to make their meetup really special. What we’ve seen so far is really incredible, and when you get involved it will be even better.

Check out the Meetups map for one in your area. When you find one in your area, join by clicking the “Join this Event” button in the upper right of the event page. If you don’t see one in your area, take the plunge and set up your own!

Tales Of Garage Design: Achieving Precision From Imprecise Parts

April 12, 2016 by 48 Comments

Designing parts to fit perfectly together is hard. Whether it’s the coarseness of our fabrication tools or the procedures of the vendor who makes our parts, parts are rarely the exact dimension that we wish they were. Sadly, this is the penalty that we pay by living in a real world: none of our procedures (or even our measurement tools!) are perfect. In a world of imperfect parts, imperfect procedures, and imperfect measurement techniques, how on earth are we supposed to build anything that works? Fortunately, we’re in luck! From the brooding minds of past engineers, comes a suite of design techniques that can combat the imperfections of living in an erroneous world.

Continue reading “Tales Of Garage Design: Achieving Precision From Imprecise Parts” →

Universities Envision Flying Beetle Swarms; But Crawl Before You Fly

April 12, 2016 by 132 Comments

Researchers at Nanyang Technical University and the University of California at Berkley wanted to answer the question: how do you make a small drone that can fly all day? The problem is that a drone needs a battery or other energy source, but a big battery needs a big drone.

Their answer? Take a giant beetle and strap enough electronics onboard to deliver tiny shocks to direct the insect’s flight. The tiny shocks don’t take much power and once the beetle is on course, no further shock is necessary unless the human pilot needs to correct the direction. Recent work allows a similar controller to control each leg of the beetle, turning it into a more versatile flying or walking cyborg.

Continue reading “Universities Envision Flying Beetle Swarms; But Crawl Before You Fly” →

Dump Your (Old) Computer’s ROM Using Audacity

April 12, 2016 by 32 Comments

If you’ve got an old calculator, Commodore 64, or any other device that used a tape recorder to store and retrieve data, you’ve probably also got a bunch of cassettes lying around, right? Well, you can get rid of them now (or sell them to nostalgic collectors for outrageous prices) because you can just as easily dump them to Audacity, decode them and archive them on a more sane medium.

In [Kai]’s case, the computer was a Sharp Pocket Computer system, and in his post there’s a lot of detail that’s specific to that particular system. If that’s applicable to you, go read up. In particular, you’ll be glad to find that the Pocket-Tools is a software suite that will encode and decode files between the Sharp binary formats and audio. Along the way, we found similar tools for Casio pocket computers too.

For a more general-purpose approach, like if you’re trying to dump and load data from a more standard computer that uses 1200/2400 Hz FSK encoding, this Python library may be useful, or you can implement the Goerzel algorithm yourself on your platform of choice. If you’ve got a particular binary format in mind, though, you’ll have to do the grunt work yourself.

Anyone out there still using these audio data encodings? We know that ham radio’s APRS system runs on two tones. What else? Why and when would you ever transfer data this way these days?

via the Adafruit blog!

Flying The Infinite Improbability Drive

April 11, 2016 by 105 Comments

Not since the cold fusion confusion of 1989 has the pop science media industry had a story like the EmDrive. The EmDrive is a propellantless thruster – a device that turns RF energy into force. If it works, it will revolutionize any technology that moves. Unlike rocket motors that use chemicals, cold gas, ions, or plasma, a spacecraft equipped with an EmDrive can cruise around the solar system using only solar panels. If it works, it will violate the known laws of physics.

After being tested in several laboratories around the world, including Eagleworks, NASA’s Advanced Propulsion Physics Laboratory, the concept of a device that produces thrust from only electricity is still not disproven, ridiculed, and ignored. For a device that violates the law of conservation of momentum, this is remarkable. Peer review of several experiments are ongoing, but [Paul] has a much more sensational idea: he’s building an EmDrive that will propel a cubesat.

Make no mistake, our current understanding of the universe is completely incompatible with the EmDrive. The idea of an engine that dumps microwave energy into a metal cone and somehow produce thrust is on the fringes of science. No sane academic physicist would pursue this line of research, and the mere supposition that the EmDrive might work is irresponsible. Until further peer-reviewed experiments are published, the EmDrive is the fanciful dream of a madman. That said, if it does work, we get helicarriers. Four EmDrives mounted to a Tesla Roadster would make a hovercar. Your grandchildren would only see Earth’s sun as a tiny speck in the night sky.

This isn’t [Paul]’s first attempt to create a working propellantless thruster. For last year’s Hackaday Prize, [Paul] built a baby EmDrive. Unlike every other EmDrive experiment that used 2.4GHz microwaves, [Paul] designed his engine to operate on 22 to 26 GHz. This means [Paul]’s is significantly smaller and can easily fit into a cubesat. If it works, this cubesat will be able to maintain its orbit indefinitely, fly to the moon and back, or go anywhere in the solar system provided the solar panels get enough light.

While [Paul]’s motivations in creating a citizen science version of the EmDrive are laudable, Hackaday.io’s own baby EmDrive does not display the requisite scientific rigor for a project of this magnitude. Experimental setups are ill-defined, graph axes are unlabeled, and there is not enough information to properly critique [Paul]’s baby EmDrive experiments.

That said, we can’t blame a guy for trying, and the EmDrive is still an active area of research with several papers under peer review. [Paul]’s plan of putting an EmDrive into orbit is putting the cart several miles ahead of the horse, but it is still a very cool project for this year’s Hackaday Prize.

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