Parallel Compressors For Sandblasting Without Crashing Your Grid

July 12, 2016 by Adam Fabio 77 Comments

[Hannah] is restoring a 1962 Volkswagen Bug. The goal is to get the car on the road in time for her driver’s test. This is no easy task, as the lower 3 inches of all the body work is rusted out, and the engine is…. well, missing. Basically, the car needs a frame off restoration. This means that [Hannah] will have a lot of metal bodywork to clean up. One of the easiest ways to do that is sandblasting.

Large scale sandblasting is a bit different from most air-powered operations. Sandblasting needs only a modest air pressure, but a high air flow. [Hannah] need 25 Sustained Cubic Feet Per Minute (SCFM) at 80 PSI for sandblasting. Most compressors can easily supply that pressure, but 25 SCFM is asking quite a lot. She could go with an expensive 3 phase unit, or rent a diesel screw compressor. However, [Hannah] decided to connect 4 compressors in parallel to give her the flow she needed.

Connecting the air outputs in parallel is easy. The problem is the electricity. Each compressor is rated for 9 amps while running. They draw quite a bit more while starting up. The compressors have to be wired to individual 15 amp circuits to avoid blowing fuses. They also need to be started in sequence so they don’t pull down the AC for the entire house while starting.

Hannah could have used any sort of delay for this, but she chose an Arduino. The Arduino’s wall wart is wired up to the master compressor. Turning on the master powers up the Arduino which immediately starts a 2 second delay. When the delay times out, the Arduino fires up the second compressor. After several delay loops, all 4 compressors are running together.

The Arduino’s GPIO pins can’t handle 9 amp AC loads, so [Hannah] wired them to TIP120 transistors. The TIP120s drive low power relays, which in turn drive high current air conditioning relays. The system works quite well, as can be seen in the video below the break.

If you’re interested in air compressor projects, check out this setup made from an old refrigerator compressor. For more background on the TIP120, check out this article about these useful transistors.

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TritiLED Lights Up The Night, Doesn’t Make You Glow

July 11, 2016 by Adam Fabio 58 Comments

Tritium, or ³H is an isotope of hydrogen which has been used as everything from radiolabel in analytical chemistry to a booster to kickstart the chain reaction of nuclear weapons. Lately tritium’s most common use has been in key chains and jewelry. A small amount of tritium is stored in a phosphor coated glass tube. The beta decay of the tritium causes the phosphor to glow. The entire device is called a Gaseous Tritium Light Source (GTLS).

In the USA, GTLS devices are only allowed to be used in specific cases such as watches, compasses, and gun sights (MURICA!). Key chains and jewelry are considered frivolous uses and are prohibited by the nuclear regulatory commission. Of course, you can still order them from overseas websites.

The safety of GLTS devices have been hotly debated on the internet for years. They’re generally safe, unless you break the glass. That said, we’re happy getting our radiation exposure through cool hacks, rather than carrying a low-level source around in our pockets.

Enter [Ted Yapo], an amateur astronomer. After tripping over his telescope tripod one time too many, he decided to take matters into his own hands. He’s designing TritiLED, a dim LED light source which can last for years. [Ted] is using a Luxeon Z LED, driven with PWM by a PIC 12F508 8 bit microcontroller. Running at 26.3 μA, he estimates about a year of run time on a CR2032 watch battery, or a whopping 15 years on a pair of lithium AA cells. Sure he could have done it with a 555 timer, but using a micro means more features are just a few lines of code away. [Ted] took advantage of this by adding a high brightness mode, blink modes, and an exponential decay mode, which emulates the decay of GLTSs.

Best of all it’s all open source. [Ted] is publishing under the (CC-BY-SA) license on Hackaday.io.

Hacklet 115 – More Quick Tool Hacks

July 9, 2016 by Adam Fabio 10 Comments

Some of the best hacks are the tools people make to help them complete a project. I last looked at quick tool hacks back in Hacklet 53. Hackers have been busy since then, and new projects have inspired new tools. This week on the Hacklet, I’m taking a look at some of the best new quick tool hacks on Hackaday.io.

We start with [rawe] and aquarium pump vacuum pickup tool. Tweezers work great for resistors and caps, but once you start trying to place chips and other large parts, things quickly become frustrating. Commercial machines use high dollar vacuum pickup devices to hold parts. [rawe] built his own version using a cheap Chinese hand pickup tool and an aquarium pump. With some pumps, switching from air to vacuum is easy. Not with [rawe’s] pump. He had to break out the rotary tool and epoxy to make things work. The end result was worth it, a vacuum pickup tool for less than 10 Euro.

Next we have [David Spinden] with ViaConnect Circuit Board Test Tool, his entry in the 2016 Hackaday Prize. [David] wanted a spring loaded pin which could be used in .100 holes in printed circuit boards. He ended up using pins from one connector, shell from another, and packaging the whole thing up into a new tool. ViaConnect essentially makes any PCB as easy to use as a solderless breadboard. No headers required. This is great both for testing new designs and for the education sector.

Next up is our favorite quick tool hacker, [Alex Rich] with Improved Allen Wrench / Hex Key Holder. If [Alex] looks familiar, that’s because he’s the creator of the Stickvise. This time he’s come up with a new way to store and organize your Allen wrenches. Inspired by a similar device seen on a YouTube video from [Tom Lipton], [Alex] opened up his CAD software and started designing. The original used a steel spring to keep the wrenches in place. [Alex] switched the spring to a rubber o-ring. The o-ring securely holds the wrenches, but allows them to be easily pulled out for use. Of course the design is open source, so building your own is only a couple of hours of printing away!

Finally we have [Solarcycle] with Cordless Foam Cutting Tool – USB Rechargeable. Soldering irons make a lot of heat in a small area to melt metal. Foam cutters make heat in a larger area to cut Styrofoam. [Solarcycle] saw the relation and converted a Solderdoodle Pro cordless soldering iron into a banjo style hot wire foam cutter. A barrel connector converts the soldering iron tip output to two stiff wires. The stiff wires carry current to a 3 cm length of Kanthal iron-chromium-aluminium (FeCrAl) heating element wire. If you don’t have any Kanthal around, ask your local vape enthusiast – they have tons of it. The result is the perfect hand-held tool for carving and sculpting in foam. Just make sure to have lots of ventilation.

If you want to see more of these hacks, check out our newly updated quick tool hacks list! See a project I might have missed? Don’t be shy, just drop me a message on Hackaday.io. That’s it for this week’s Hacklet, As always, see you next week. Same hack time, same hack channel, bringing you the best of Hackaday.io!

Triple Monitor Travel Battlestation

July 7, 2016 by Adam Fabio 19 Comments

[AbyssalUnderlord’s] schedule has him packing up and moving between school, home, and internships every three months. Not an easy task when your computer is a triple monitor CAD and gaming powerhouse. To make his moves easier, he built this portable computer / monitor frame.

The design started with a CAD model. The basic materials for the build are aluminum angle and steel-slotted angle stock. There was no welding involved in this build. Pop rivets, nuts, and bolts hold just about everything together. An angle grinder was used for all of the cutting. [AbyssalUnderlord] used drawer slides to move his monitors from stored to deployed position. The small red extensions at the end of the drawer slides allow the monitors to be positioned in a standard 3 wide triple monitor setup. It’s a clever design.

This schedule isn’t going to last forever so [AbyssalUnderlord] didn’t want to make any permanent mods to his tower or monitors. Blue camping foam acts as a cushion between the hardware and the new case.

We’ll admit that this isn’t the prettiest of builds, but it looks plenty rugged and it gets the job done. As mentioned in the Reddit thread, a few coats of spray paint would go a long way toward improving the aesthetics. Just don’t spend too much time playing Overwatch, [AbyssalUnderlord].

If you like DIY portable setups, check this Transformers-themed portable workbench, or our Hacklet all about portable work stations and toolboxes.

Hacklet 114 – Python Powered Projects

July 2, 2016 by Adam Fabio 5 Comments

Python is one of today’s most popular programming languages. It quite literally put the “Pi” in Raspberry Pi. Python’s history stretches back to the late 1980’s, when it was first written by Guido van Rossum. [Rossum] created Python as a hobby project over the 1989 Christmas holiday. He wanted a language that would appeal to Unix/C hackers. I’d say he was pretty successful in that endeavor. Hackers embraced Python, making it a top choice in their projects. This week’s Hacklet focuses on some of the best Python-powered projects on Hackaday.io.

We start with [Jithin] and Python Powered Scientific Instrumentation tool, his entry in the 2015 Hackaday Prize. [Jithin] has created an “electronics lab in a box” style tool that can compete with commercial products with price tags in the thousands. Python Powered Scientific Instrumentation tool uses simple microcontroller powered hardware to create programmable gain amplifiers, waveform generators, LCR meters, CC sources and more. The microcontroller handles all the real-time operations. Data processing happens on a connected PC running Python scripts. Popular Python libraries like Scipy make signal processing and waveform displays easy.

Next up is [Bill Peterson] with jamPi. [Bill] loves his music keyboard, but hates having to lug around a laptop, audio interface, and all the associated cables. He needed a device which would be as flexible as a PC-based synthesizer, but as simple and compact as a MIDI sound module. JamPi does all this and more. [Bill] is using fluidsynth to generate sound. The control and interface software is handled in Python with the help of the fluidsynth.py module. All this functionality is wrapped up in a simple box with a 2 line character LCD. Now [Bill] is ready to jam anytime, anywhere.

Next is [i.abdalkader] with OpenMV, his entry in the 2014 Hackaday Prize. [i.abdalkader’s] goal was to create “the Arduino of machine vision”. He’s well on his way to accomplishing that. In 2015, OpenMV had a successful Kickstarter campaign. After a few manufacturing glitches, customers are now receiving their devices. OpenMV is a low-cost Python-powered machine vision device. An ARM microcontroller coupled to a simple image sensor makes up the core of the device. The camera is programmed in MicroPython, with the help of many image processing libraries created by the OpenMV team. [i.abdalkader] even created his own IDE using Glade and PyGTK.

Finally we have [osannolik] with Calibration and Measurement Tool. Have you ever want to display a few debug parameters from your embedded project, but didn’t have the display real estate (or any display at all)? What about changing a parameter without pulling out your JTAG setup and firing up your debugger? [Osannolik] has created a simple Python powered PC-based front end which can be used as a Swiss army knife for developing embedded systems. Variables can be displayed in real-time, parameters changed. Even graphs are available thanks to pyqtgraph.

If you want more Python-powered goodness, check out our new Python-powered project list! Did I miss your project? Don’t be shy, just drop me a message on Hackaday.io. That’s it for this week’s Hacklet. As always, see you next week. Same hack time, same hack channel, bringing you the best of Hackaday.io!

HALT In The Name Of Testing

July 1, 2016 by Adam Fabio 16 Comments

“Did I forget something?” It’s that nagging feeling every engineer has when their project is about to be deployed – it may be a product about to be ramped into production, a low volume product, or even a one off like a microsatellite. If you have the time and a few prototypes to spare though, there are ways to alleviate these worries. The key is a test method which has been used in aerospace, military, and other industries for years – Highly Accelerated Life Testing (HALT).

How to HALT

The idea behind HALT testing can be summed up in a couple of sentences:

Beat your product to death.
Figure out what broke.
Fix it, and fix the design.
Repeat.

Sounds barbaric, and in many cases it is. HALT testing is often associated with giant test chambers which are literally designed to torture anything inside them. Liquid nitrogen shock cools the chamber as low as -100°C. The Device Under Test (DUT) can soak at that temperature for hours. Powerful heaters then blast the chamber, causing temperature rises of up to 90°C per minute, topping off at up to 200°C. Pneumatic hammers beat on the chamber table causing vibrations at up to 90 Grms and 10 KHz. Corrosive sprays simulate years of rain and humidity. These chambers are literally hell on earth for any device unlucky enough to be placed inside them. It’s easy to see why this sort of testing is often referred to as “Shake and Bake”.

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Hacklet 113 – New Robots

June 25, 2016 by Adam Fabio 4 Comments

I start each day checking out the new and updated projects over on Hackaday.io. Each day one can find all manner of projects – from satellites to machine vision to rockets. One type of project which is always present are robots- robot arms, educational ‘bots, autonomous robots, and mobile robots. This week’s Hackaday.io had a few great robot projects show up on the “new and updated” page, so I’m using the Hacklet to take a closer look.

We start with [Jack Qiao] and Autonomous home robot that does things. [Jack] is building a robot that can navigate his home. He’s learned that just creating a robot that can get itself from point A to point B in the average home is a daunting task. To make this happen, he’s using the Simultaneous Localization and Mapping (SLAM) algorithm. He’s implementing SLAM with the help of Robotic Operating System (ROS). The robot started out as a test mule tethered to a laptop. It’s evolved to a wooden base with a mini ITX motherboard. Mapping data comes in through a Kinect V2, which will soon be upgraded to a Neato XV-11 LIDAR system.

Next up is [Tyler Spadgenske] with TyroBot. TyroBot is a walking robot with some lofty goals, including walking a mile in a straight line without falling down. [Tyler’s] inspiration comes from robots such as Bob the Biped and Zowi. So far, TyroBot consists of legs and feet printed in PLA. [Tyler] is going to use a 32 bit processor for [TyroBot’s] brain, and wants to avoid the Arduino IDE at any cost (including writing his own IDE from scratch). This project is just getting started, so head on over to the project page and watch TyroBot’s progress!

Next is [Mike Rigsby] with Little Friend. Little Friend is a companion robot. [Mike] found that robots spend more time charging batteries than interacting. This wouldn’t do for a companion robot. His solution was to do away with batteries all together. Little Friend is powered by super capacitors. An 8 minute charge will keep this little bot going for 75 minutes. An Arduino with a motor shield controls Little Friend’s DC drive motors, as well as two animated eyes. If you can’t tell, [Mike] used a tomato as his inspiration. This keeps Little Friend in the cute zone, far away from the uncanny valley.

Finally we have the walking robot king, [Radomir Dopieralski], with Logicoma-kun. For the uninitiated, a Logicoma is a robot tank (or “logistics robot”) from the Ghost in the Shell series. [Radomir] decided to bring these cartoon tanks to life – at least in miniature. The bulk of Logicoma-kun is built carefully cut and sculpted acrylic sheet. Movement is via popular 9 gram servos found all over the internet. [Radomir] recently wrote an update outlining his new brain for Logicoma-kun. An Arduino Pro Mini will handle servo control. The main computer will be an ESP8266 running Micropython. I can’t wait to see this little ‘bot take its first steps.

If you want more robotic goodness, check out our brand new mobile robot list! Did I miss your project? Don’t be shy, just drop me a message on Hackaday.io. That’s it for this week’s Hacklet, As always, see you next week. Same hack time, same hack channel, bringing you the best of Hackaday.io!