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Repaired Manned Multicopter Flies without Horrifying Crash

3 hours 55 minก่อน

[amazingdiyprojects] has been making lots of test flights in his crazy eight propeller gasoline powered danger bucket.

We last covered the project when he had, unfortunately, wrecked the thing in a remote-controlled test flight.  He later discovered that the motor’s crankshaft bearings had, well, exploded. The resulting shrapnel destroyed the motor and crashed the drone. He described this failure mode as “concerning”.

Also concerning is the act of stepping into the seat once all the propellers are started up. He tags this as “watch your step or die”. Regardless, he also describes flying in the thing as so incredibly fun that it’s hard to stay out of it; like a mechanical drug. It explains why his channel has been lately dominated by videos of him testing the multicopter. Those videos are found after the break.

The device drinks 0.65-0.7 liters per minute of gasoline, and he’s been going through reserves working out all the bugs. This means everything from just figuring out how to fly it to discovering that the dust from the ground effect tends to clog up the air filters; which causes them to run lean, subsequently burning up sparkplugs. Dangerous, but cool.


Filed under: drone hacks

Ask Hackaday: Is The ESP8266 5V Tolerant?

5 hours 9 minก่อน

The ESP8266 is the reigning WiFi wonderchip, quickly securing its reputation as the go-to platform for an entire ecosystem of wireless devices. There’s nothing that beats the ESP8266 on a capability vs. price comparison, and this tiny chip is even finding its way into commercial products. It’s also a fantastic device for the hardware tinkerer, leading to thousands of homebrew projects revolving around this tiny magical device.

In every technical document, summary, and description of the ESP8266, the ESP8266 is said to be a 3.3V part. While we’re well into the age of 3.3V logic, there are still an incredible number of boards and hardware that still operate using 5V logic. Over on the Hackaday.io stack, [Radomir] is questioning this basic assumption. He’s wondering if the ESP8266 is 5V tolerant after all. If it is, great. We don’t need level converters, and interfacing the ESP to USB TTL serial adapters becomes much easier. Yes, you’ll still need to use a regulator if the rest of your project is running at 5V, but if the pins are 5V tolerant, interfacing the ESP8266 with a variety of hardware becomes very easy.

[Radomir]’s evidence for the possibility of 5V tolerant inputs comes from a slight difference in the official datasheet from Espressif, and the datasheet translated by the community before Espressif realized how many of these chips they were going to sell.

The best evidence of 5V tolerant pins might come from real-world experience — if you can drive a pin with 5V for months on end without it failing, there might be something to this claim. It’s not definitive, though; just because a device will work with 5V input pins for a few months doesn’t mean it won’t fail in the future. So far a few people have spoken up and presented ESPs directly connected to the 5V pin of an Arduino that still work after months of service. If this is evidence of 5V tolerant design or simply luck is another matter entirely.

While the official datasheet from Espressif lists a maximum VIH of 3.3V, maximum specs rarely are true maximums — you can always push a part harder without things flying apart at the seams. Unfortunately, unless we hear something from the engineers at Espressif, we won’t know if the ESP8266 was designed to be 5V tolerant, if it can handle 5V signals reliably, or if 5V signals are a really good way to kill a chip eventually.

Lucky for us — and this brings us to the entire point of an Ask Hackaday column — a few Espressif engineers read Hackaday. They’re welcome to pseudonymously chime in below along with the rest of the peanut gallery. Failing that, the ESP8266 has been decapped; are there any die inspection wizards who can back up a claim of 5V tolerance for the GPIO? We’d also be interested in hearing any ideas for stress testing pin tolerance.


Filed under: Ask Hackaday, Hackaday Columns

Amazing SDR Built by 16 Year Old

พฤ, 07/28/2016 - 22:31

[Lukas] started his epic SDR-from-scratch build when he was 16. Projects like this aren’t completed overnight. (He’s now 18. We’re impressed.)

The project itself is a Software-Defined Radio built on top of the 12-bit Analog Devices AD9364 transceiver IC. A big fat FPGA takes the data and runs it off to a USB 3.0 interface, which is necessary for the amount of data this thing will be producing — he’s got it receiving 56 MHz of bandwidth. In short, this is an SDR peripheral that’s in the big leagues.

After two years of work and (only!) three revision, [Lukas] got the thing working. Read his writeup for the blow-by-blow account. In the end, a 6-layer board was necessary for the routing to get the full speed out of the clocking, and he discovered the reason that you use exactly the specified bias resistors — the expensive ADC chip gets very hot. But he didn’t give up, and in the end he pulled off a project of immense complexity. In his own words:

I have discovered that taking on large projects, even when not knowing how to tackle problems that might arise, is a very effective way of learning for me. It’s just important to be persistent, as I’ve seen that almost any problem can be solved on your own — which is incredibly rewarding — even if you get stuck and seem to not make progress for a while.

[Lukas] is now working on the software. He’s already got a hacked osmocom driver working, so it plays nice with GNURadio.

Of course, there are tons of ways to get into SDR without building your own from scratch, but we applaud [Lukas] for going the hard way. If you’re tempted to follow in his footsteps, have a look at [Michael Ossmann]’s great talk on making the RF design process as tractable as possible.


Filed under: radio hacks

Power Log Splitting: Trying (and Sometimes Failing) to Build a Better Ax

พฤ, 07/28/2016 - 21:01

Wood. Humans have burned it for to heat their homes for thousands of years. It’s truly a renewable source of energy. While it may not be the most efficient or green method to warm a space, it definitely gets the job done. Many homes still have a fireplace or wood burning stove for supplemental heat. For those in colder climates, wood is more than just supplemental, it’s needed simply for survival.

Splitting maul by Chmee2 via Wikipedia

The problem with firewood is that it doesn’t come ready to burn. Perfect fireplace sized chunks don’t grow on trees after all. The trees have to be cut up into logs. The logs must be split. The split wood then needs to dry for 6 months or so.

Anyone who’s spent time manually splitting wood can tell you it’s back breaking work. Swinging an 8 pound maul for a few hours will leave your hands numb and your shoulders aching. It’s the kind of work that leaves the mind free to wander a bit. The hacker’s mind will always wander toward a better way to get the job done. Curiously we haven’t seen too many log splitting hacks here on the blog. [KH4] built an incredible cross bladed axe back in 2015, but that’s about it.

There are a ton of commercial firewood splitters out there. For every commercial model, there are hackers designing, bolting, and welding their own splitters. Many of these homemade devices find their way to the internet. As you probably can imagine, ideas and implementations range from high tech to redneck.

Wood Meets Pressurized Oil

The most common powered log splitter is a hydraulic design. These are the same types of splitters you might see for sale at your local big box home center. A steel I-beam, hydraulic cylinder, gas engine, and a pump are the basic building blocks of a splitter like this. Think of it as a horizontal version of the machine used in the hydraulic press channel. The cylinder moves a push block, which shoves the log into a wedge. A great example of a home built hydraulic splitter can be found on [Smalls4068’s] YouTube channel.

Hydraulic splitters get work done faster than manual splitting, but you still have to wait for the cylinder to retract. [Ricky Cupp’s] built himself a two way splitter. The wedge is mounted in the center in this system. The push block can then push (or pull) a log into the wedge from either side. If simply splitting a log in two isn’t enough for you, check out [1D10CRACY]. His machine can cut a large log into four chunks at a time. More splits require more force though, which means larger cylinders and bigger engines.

Wood Meets Spinning Wheel (of Doom)

Some folks have a need for more speed. The hydraulics used in log splitters aren’t exactly fast devices. Kinetic splitters are the solution here. Kinetic splitters use a small engine to spin up a flywheel. When the splitter is activated, the flywheel’s pinion gear is engaged with a rack. The rack pushes the wood into the wedge. Sounds complex, but [Gary Gilmore] does a great job of explaining his design in this video. The flywheel on his splitter began life as part of a bulldozer diesel engine. 75 lbs of steel spinning at several hundred RPM generates quite a bit of force!

Then we come to a class of log splitters where common sense exits stage left. These are flywheel splitters, sometimes called widowmakers. The winner for scariest machine we’ve seen this week goes to [Jack Dickson] and his creation “The Wheel of Debt” [Jack] turned a pile of steel scrap into a device which makes us cringe just watching it. An 8 pound maul head is welded to a built up steel wheel. The wheel is spun by a small engine through a belt and car tire arrangement. The relatively lightweight wheel must spin quickly to generate enough force to split logs. This video was Jack’s last upload, so we can only assume his creation eventually got him. ‘

Wood Meets Pointy Metal

There are other versions of the widowmaker out there. Those with heavier, slower spinning wheels manage to do the job with less drama, but accidents are just around the corner.

One final type of log splitter is the rotary splitter, also known by the brand name Unicorn. These splitters use a threaded rotating cone to drill into the log and split it apart. Sounds a bit dangerous, right? A commercial version called The Stickler is still available. The Stickler is designed for rear wheel drive vehicles. That didn’t stop [Mikelbonilla78] from hacking his ‘92 Honda Civic into a stationary log splitter. He even added an exterior throttle and emergency battery disconnect. Even with these safety features, we’re going to go ahead and say this one is scary.

So we turn the question over to you, our fine readers. Those who do have the unhappy task of splitting wood, what hacks have you come up with to make the job easier?


Filed under: Featured, Interest, tool hacks

Computer-Designed Portraits, Knit By Hand!

พฤ, 07/28/2016 - 18:01

Artist [Petros Vrellis] has done something that we’ve never seen before: his piece “A New Way to Knit” lives up to its name. What he’s done is to take the traditional circular loom, some black thread, and toss some computing at it. And then he loops the string around and around and around.

The end result of following the computer’s instructions is a greyscale portrait. Where few black strings overlap, it’s light, and where more overlap, it’s darker. That’s the whole gimmick, but the effect is awesome. As you zoom in and out, it goes from a recognizable face to a tangle of wires and back. Check out his video embedded below.

There’s at least a few ways to do this, so we e-mailed [Petros] to ask. He assigned darker pixels in the original image a higher score, and ran the string to the opposing pin that maximizes the sum of the pixels passed through. With each string, he subtracted off a bit of darkness from all of the pixels along the string’s path, and repeated, starting each time at the new pin location. Each string has “only” 200 choices to make times 3000-4000 passes, so a computer should be done in no time. Tuning this algorithm to work just right, and look good with real string is probably just about as easy as it sounds. For instance, he had to include code to break ties.

Although we love the man-machine cooperation on the piece, [Petros] mentioned that he’s tempted to automate the weaving. Check out his two pendulum-based pieces (here, and here) if you like more machines in your art.

While on the topic of portraits made with black string, we have to remind you of this previous art piece that does all the work of actually laying the string out by using a modified 3D printer. Beauty is in the eye of the beholder, but we have to say that if art were judged on a difficulty scale, [Petros] would win for using only a circular loom. Never mind that he did it all by hand.


Filed under: misc hacks, slider

All-terrain Hoverboard Junk Pile Build

พฤ, 07/28/2016 - 15:01

If you’re anything like us, chances are pretty good you’ve got at least one underused piece of fitness gear cluttering up your place. Rather than admit defeat on that New Year’s Resolution purchase, why not harvest the guts and build an all-terrain hoverboard for a little outdoor fun?

The fitness machine in question for [MakeItExtreme]’s build was a discarded Crazy Fit vibration platform. We’re not sure we see the fitness benefits of the original machine, but there’s no doubt it yielded plenty of goodies. The motor and drive belt look stout, and the control board eventually made it into the hoverboard too. The custom steel frame was fabricated using some of [MakeItExtreme]’s DIY tools, which is what we’re used to seeing them build — check out their sand blaster and spot welder for examples. A couple of knobby tires in the center of the board let the rider balance (there’s no gyro in this version) and power is provided by a couple of 12 volt AGM batteries. Sadly, the motor was a line voltage unit, so an inverter was needed. But it was the only part that had to be purchased, making this a pretty complete junk pile build.

See the video after the break for build details and a few test rides. Looks like it can do 20 mph or so – pretty impressive.


Filed under: misc hacks, transportation hacks

Hackaday Prize Entry: A Suite Of Lab Instruments

พฤ, 07/28/2016 - 12:00

For their Hackaday Prize entry, [Jithin], [Praveen], [Varunbluboy], and [Georges] are working on SEELablet, a device that will equip budding citizen scientists with control and measurement equipment.

One of the best ‘all-in-one’ lab devices is National Instruments’ VirtualBench, a device that’s an oscilloscope, logic analyzer, function generator, multimeter, and power supply, all crammed into one box. There’s a lot you can do with a device like this, but as you would expect, the name-brand version of this isn’t meant for middle school students.

In an effort to bring the cost of an all-in-one lab tool down to a price mere mortals can afford, the team behind the SEELablet have combined a single board computer with the capability of an oscilloscope, frequency counter, logic analyser, waveform generator, and a programmable power supply.

This has been a multi-year project for the team, beginning with a Python-powered instrumentation tool, and later a device running this code that’s also a versatile lab tool. If the latest iteration of the project turns out to be all it promises, we can’t wait to see the data this box will produce. There’s a lot you can measure in a fully stocked electronics lab, and this project makes the whole setup much easier to obtain.

The HackadayPrize2016 is Sponsored by:
Filed under: The Hackaday Prize

FPGA Drives Old Laptop Screen

พฤ, 07/28/2016 - 09:00

Every year, new models of laptops arrive on the shelves. This means that old laptops usually end up in landfills, which isn’t exactly ideal. If you don’t want to waste an old or obsolete laptop, though, there’s a way to reuse at least the screen out of one. Simply grab an FPGA off the shelf and get to work.

[Martin] shows us all how to perform this feat on our own, and goes into great detail about how all of the electronics involved work. Once everything was disassembled and the FPGA was wired up, it took him a substantial amount of time just to turn the display on. From there it was all downhill: [Martin] can now get any pattern to show up on the screen, within reason. The only limit to his display now seems to be the lack of external RAM. He currently uses the setup to drive an impressive-looking clock.

This is a big step from days passed where it was next to impossible to repurpose a laptop screen. Eventually someone discovered a way to drive these displays, and now there are cheap electronics from China that can usually get a screen like this running. It’s impressive to see it done from scratch, though, and the amount of detail in the videos are a great way to understand how everything is working.


Filed under: FPGA

Build a Foam Cutter Right Now

พฤ, 07/28/2016 - 06:00

Cutting foam is difficult with traditional methods. The best way is with a hot wire. If you read Hackaday, it is a good bet you can figure out how to use electricity to make a wire hot without any help. However, there’s something  clever about [MrGear’s] minimal build.

As you can see in the video below, he uses a 9V battery, a clip, some popsicle sticks, and the wire from a ballpoint pen. He also used a switch, but we couldn’t help but think that was unnecessary  since you could just unclip the battery to turn the device on and off. Since he used hot glue to attach the switch to the battery, replacing the battery would be a pain.

This is a quick tool for short-term use: we imagine shorting out a 9V battery will require you to replace the battery fairly often. Of course, you could probably use a lantern battery if you wanted something that would last longer. Just don’t use a lithium ion battery since shorting them is very dangerous.

If you want something more involved, have a look at [Grant Thompson’s] build (see second video, below) that is a lot more substantial. He uses a strand of steel hanging wire for the cutting element and a spring to keep it tense. He also has a good trick for getting the waves out of the wire, that might come in handy even if you build the [MrGear] version. Looking for something between those two extremes? We’ve covered several foam cutters in the past.


Filed under: tool hacks

DIY Smart Home Device Means No More Fumbling in the Dark

พฤ, 07/28/2016 - 03:00

Smart home tech is on the rise, but cost or lack of specific functionality may give pause to prospective buyers. [Whiskey Tango Hotel] opted to design their own system using a Raspberry Pi and Bluetooth device connectivity. Combining two ubiquitous technologies provides a reliable proximity activation of handy functions upon one’s arrival home.

The primary function is to turn on a strip of LEDs when [Whiskey Tango Hotel] gets home to avoid fumbling for the lights in the dark, and to turn them off after a set time. The Raspberry Pi and Bluetooth dongle detect when a specified discoverable Bluetooth device comes within range — in this case, an iPad — after some time away. This toggles the Pi’s GP10 outputs and connected switching relay while also logging the actions to the terminal and Google Drive via IFTTT.

[Whiskey Tango Hotel] has included their Python code and build steps at the end of their blog post to help save you some time should you start a similar project. Indeed, the Raspberry Pi + Bluetooth combo can be used to great effect in many different areas — like adding non-standard functionality to your vehicle’s stereo.


Filed under: home hacks, Raspberry Pi

Yes, You Should be Hacking Your Car’s Data System

พฤ, 07/28/2016 - 01:31

If you own a car, I would wager it’s the most complex device you own. Within you find locomotion, safety systems, and an entertainment system that may be using technology from several decades ago (but that’s a rant for a different article). Jalopy or Sweet Hotness, your ride has an underlying data network that is a ton of fun to hack, and something of a security dinosaur. Both were discussed by Craig Smith and Erik Evenchick during their talk on Car Hacking tools at Hope XI.

You should recognize both of these names. Eric Evenchick is a Hackaday contributor who has been traveling the world presenting talks and workshops on his open source car hacking hardware called CANtact. Craig Smith is founder of OpenGarages and author of the Car Hacker’s Handbook which we highly recommend. The pair made a great joint presentation; both were charismatic, using wit to navigate through the hardware, software, techniques, and goals you want to have in mind to jump into car hacking.

It’s all in the CAN

One thing you can almost always say about automotive is that they have robust and well-defined standards. There are so many vehicles on the road and the support for that hardware needs to last so long that parts tend to be standardized and documentation can almost always be found. Every car has a standardized port to patch into the CANbus — the system that carries data to every piece of electronics in the vehicle. Want to roll down the window, change the radio station from the steering wheel, or tweak the mix going into the combustion chamber? Look to the CANbus.

To the uninitiated this can be scary, but there are a ton of options to ease you into CANbus hacking. You can try your hand and reading, parsing, reverse engineering, and formulating CAN messages in software if you like. Craig has put together two software trainers. The first is based on SuperTuxKart (think Mario Kart for the Linux crowd) which spits out accurate CAN messages as you drive the Kart around. The second, called ICsim, uses a gaming controller to operate a virtual vehicle and is much more sophisticated aimed at teaching reverse engineering. The output includes many more messages (like the noisy deluge you see on a real vehicle) and challenges you to sleuth your way to associate meaning with the messages you are hunting for.

Your Car’s Hardware (for the brave) or Fake It (for the meek) Junkyard acquired test bench (via @OpenGarages)

You can just jump right into plugging hardware into your own car and hacking away. Craig knows that may be a hard sell so he has a clever solution: hit the junkyard and build a test bench on the cheap.

Here you can see an instrument cluster, Electronic Control Unit (ECU), and the keys. Connect everything together, throw in a 12V PSU and you’ve got most of the interesting bits you’d want. Craig uses a couple of trimpots to stand in for the fuel level and engine temperature which are resistive sensors.

Whether hacking your own car or a junkyard unit you need a tool that can speak the language of the CANbus. The good news is that there are many options and for the most part they’re in the sub-$100 range. This is where Eric Evenchick’s part of the talk comes into play.

CANtact hasn’t had a ton of coverage yet on Hackaday. We featured it just after release but it would be great to hear more about what people are accomplishing with the hardware so send in a tip if you have a good story. The device is a USB-to-CANbus bridge that speaks to all of the best CAN hacking tools.

As we heard during Eric’s village talk at DEF CON last year, the CANtact plays nicely with socketCAN which is the go-to suite of open source CAN hacking software (eg: candump, cansniffer, cansend, cangw). But since then he has developed a new cross-platform Java app to help open up CANtact for use on OSX/WIN.

Playing with CAN and Exploring the Security Nightmare

There is so much potential for fun when you get on the CAN bus. The obvious includes things like making your instrument cluster scroll messages, and moving your windshield wipers to an asymmetrical delay. But digging a bit deeper there are some really crazy security issues here.

Craig discussed one to which you can immediately relate: if your vehicle can be paired to a phone over Bluetooth you can probably access your phone’s contacts through the CAN bus. How’s that for a challenge? Even more crazy is going the opposite way. The Bluetooth stack on an automobile is likely never to be updated. Find out the BT version on your car and look up any known vulnerabilities, then see if you can get all the way down to the CANbus by exploiting Bluetooth.

Yes, this is crazy. The only security for the CANbus is by obscurity. Manufacturers don’t publish a reference manual for CAN packets so car hacking involves a lot of reverse engineering to capture and make sense of these messages. One of the future goals of OpenGarages is to put together a crowdsourced database of these packets including import and export of Kayak and DBC message formats.

One of the questions at the end of the talk asked about the ODB-II Dongles being pushed by insurance companies right now. ODB-II is the standard connector to a vehicle’s CANbus and this gives your insurance a Big-Brother-esque look at how you drive. But once on the CANbus they can harvest any information they want and can even write to it without any logging. This could even be used to rewrite firmware for devices like the airbag controller. The point isn’t that an Insurance company would do this, but that allowing access by anyone to the car’s network is a huge security hole.

Craig thinks at the very least vehicles should have logging and mentions that autonomous car research has taken an entirely different approach which by default doesn’t trust devices on the CANbus. Instead they use redundant sensor data to verify that each device is working and that its data can be trusted.


Filed under: car hacks, cons

3D Printering: Non-Planar Layer FDM

พฤ, 07/28/2016 - 00:01

Non-planar layer Fused Deposition Modeling (FDM) is any form of fused deposition modeling where the 3D printed layers aren’t flat or of uniform thickness. For example, if you’re using mesh bed leveling on your 3D printer, you are already using non-planar layer FDM. But why stop at compensating for curved build plates? Non-planar layer FDM has more applications and there are quite a few projects out there exploring the possibilities. In this article, we are going to have a look at what the trick yields for us.

Smooth, Curved Surfaces

Non-planar-layer FDM allows for smooth, curved surfaces, which otherwise would show the typical staircase of discrete layers. Usually, I’m relying heavily on sand paper and spray filler to upgrade my 3D prints to Class-A, and I’ve been quite surprised by how smooth the non-planar test prints came out directly from the machine:

While the discrete layers aren’t always a problem when printing functional, mechanical parts, there may be applications where this comes in quite handy. The lack of discrete layers gives the models a nice look that requires no further smoothing, which may be helpful in design applications. The smooth surfaces may also help 3D printing aerodynamic models, like the airplane wing from the header photo:

Strengthened Parts

Non-planar printed parts seem to be stronger than their planar counterparts. You may be skeptical about this — although the varying orientation of the contact surfaces between layers could lead to a more uniform resistance to tensile stress. Planar printed FDM parts are typically less resistant to tensile stress along the build direction axis than they are along the other two dimensions, which can lead to delamination. Interlocking, non-planar layers can distribute tensile forces into a compound of tensile and shearing forces, with the latter being a particular strength of FDM printed parts. The graphic shows how the shearing component FS increases with increased displacement:

Force distribution between layers of planar and non-planar FDM — FA: attacking force — FT: tensile component of FA — FS: shearing component of FA

By adding transitions between displaced layers and compensating for the variable layer height, it is also possible to treat only certain portions of a 3D printed part, while leaving other parts entirely untouched. The following example print features a flat top and bottom, only the layers in between have been gradually displaced.

The slight wave in the above example may not exhaust the effect entirely. Unfortunately, my printer currently does not feature a very pointy nozzle, which limits its capability of printing steep curves. To make it easier to spot the displacement, I changed the material color mid-print. Any strengthening effect will certainly only be as good as the individual implementation, and eventually: Until this has been verified through measurement, I’d rather not stress this theoretical argument for non-planar layer FDM too much.

Structured Surfaces

Just like a tree stump reveals the annual rings of the tree, 3D printed objects also show signs of their formation process through the typical rippled structure along their outer shells. Objects printed in a planar fashion typically also show tool paths of infill and perimeters on their top layers. Non-planar layers allow you to add additional textures to the flat top surfaces of your prints, which may be especially interesting in custom design applications. The cube below has been printed using a 2D-sinusoidial displacement pattern.

These textures occur similarly to the mentioned tree-rings. Flat top layers of non-planar printed objects represent a cross-section through the displacement pattern, which results in interesting patterns by itself. It’s up to the individual application and taste if the creation of these patterns is desirable, yet I happen to find them quite beautiful.

Hands-On

Ideally, non-planar 3D printing is done using a somewhat pointy nozzle, as flat nozzles tend to dig into the previously printed material and easily get entangled in infill structures. Generally, a pointy nozzle allows for steeper printing angles, although you always need to make sure that no other parts of the nozzle or print-head are getting in the way. Especially fan mounts or ducts are prone to collide with parts of the print. I’m using an E3Dv6 hotend and nozzle for the examples in this post, although there are probably better solutions out there. In particular, the Merlin hotend features a very fine and pointy nozzle, with the only thing that could get into the way being the heater block.

The non-planar tool paths require a lot of action on the Z-axis, now is the time to add some fresh grease to its mechanics. Depending on how fast your Z-axis can move, you may also readjust its maximum speed and jerk settings in the firmware.

Using the template code of the G-code post-processing article last week, I put together a little script that lets you generate non-planar G-code on the fly using Slic3r. You can obtain the script from its GitHub repository, which also contains detailed instructions on how to use it. It also comes with several examples: The first three examples are the cube I used for the illustrations in this post, along with the same sinusoidal displacement function. The fourth example is the airplane wing model from the title graphic. The wing is based on a flat design that has been displaced to obtain the aerodynamic shape.

After exporting the G-code of this rather unspectacular design from Slic3r, which also pushes it through the post-processing script for displacement, the wing takes on its final shape. Due to the thin shells this method allows, it is very light. Still, it’s certainly not safe to fly and meant purely to illustrate the technique:

I printed the above G-code on a Prusa i3, using a 0.4 mm E3Dv6 nozzle. Even though this nozzle is not very pointy, the wing turned out quite well. Due to the suboptimal nozzle geometry, the top-side features shallow, regular grooves.

I hope you enjoyed this little excursion into off-track 3D printing. Check out the script and share your results, opinions and ideas with us in the comments!


Filed under: 3d Printer hacks, Hackaday Columns, Skills

Cyclist’s LED Pixel Clock Has No Fat Around The Middle

พุธ, 07/27/2016 - 22:30

If you like LED clocks and illuminated bicycle wheels, [Harald Coeleveld] has just the right weekend project for you. His RGB pixel LED clock is as simple as it is beautiful, and it can be built in no time: The minimalist and sporty design consist of not much more than a LED strip wrapped around a bicycle wheel rim.

[Harald] took 2 meters of addressable WS2812 LED strip (with 30 LEDs per meter, we assume), wrapped it around a 27″ bicycle rim padded with a foam strip, and obtained 60 equally spaced RGB LEDs on a ring, ideal for displaying time. Apparently, the rim-tape circumference of this particular 27″ bicycle wheel is close enough to 2 meters, so it lines up perfectly.

On the electronics side, the project employs an Arduino Nano and a DS3231 precision RTC module. For switching between two illumination modes for day and night, [Harald] also added a photoresistor. During the day, colored dots around the ring display the time: A red dot for the seconds, a blue one for the minutes, and a group of 3 green LEDs for the hours. At night, the entire ring shimmers with an effective red glow for easier readability.

The Arduino code for this build can be downloaded from the project page, enabling anyone to effortlessly replicate this design-hack in under an hour!


Filed under: clock hacks, led hacks

Design for Hackers

พุธ, 07/27/2016 - 21:01

Near the end of the lifecycle of mass-market commercial product development, an engineering team may come in and make a design for manufacturability (DFM) pass. The goal is to make the device easy, cheap, and reliable to build and actually improve reliability at the same time. We hackers don’t usually take this last step, because when you’re producing just a couple of any given device, it hardly makes sense. But when you release an open-source hardware design to the world, if a lot of people re-build your widget, it might be worth it to consider DFM, or at least a hardware hacker’s version of DFM.

If you want people to make their own versions of your project, make it easy and cheap for them to do so and don’t forget to also make it hackable. This isn’t the same as industrial DFM: rather than designing for 100,000s of boards to be put together by robot assembly machines, you are designing for an audience of penny-pinching hackers, each building your project only once. But thinking about how buildable your design is will still be worthwhile.

In this article, I’m going to touch on a couple of Design for Hackers (DFH) best practices. I really want to hear your experience and desires in the comments. What would you like to see in someone else’s open designs? What drives you nuts when replicating a project? What tricks do you know to make a project easily and cheaply buildable by the average hacker?

Design for DIY

Your audience isn’t technologically illiterate, but they’re not pick-and-place machines with micrometer positioning accuracy either. You want to make the assembly easy on them, but you don’t want to have to use through-hole components that are as big as your head and becoming more and more difficult to source all the time. What to do?

That’s not a rhetorical question. What should we do? I’m entirely happy soldering surface mount technology (SMT) down to 0805 and 0.5 mm pin-pitch with good illumination and a magnifying lens, but below that it gets tricky. People who use solder paste and reflow can handle even smaller parts. But if you require reflow skills to rebuild your project, you’re also limiting the potential audience to a small percentage of Hackaday readers, much less the entire human population.

Home etching is doable down to just about the same resolution as hand-soldering in my experience, but only with a bit of practice. Double-sided boards can be made to work at this scale with yet more practice. When your design gets complicated in these directions, you force the hacker to outsource the PCB fabrication. These days, that’s less and less of a problem, but depending on where people live it can introduce a delay even if it doesn’t add much extra cost to the project.

But if you want people to copy your design, think about the difficulty of DIY manufacture versus the gains you get from using a given technology. There are definitely discrete jumps of difficulty. Almost nobody is making four-layer PCBs at home, and relatively few are making double-sided boards. Once you need to move beyond a single-sided board with a few jumpers, you can pretty safely go nuts on the complexity of a professionally fabricated PCB, which means that you can also use tiny little track widths if you need to.

My best guess is that 1206, 0805, and the bigger SOIC parts are not show-stoppers for the average Hackaday reader even with the most brutal soldering iron, but I could be totally wrong. What’s your tolerance for bigger SMT parts? How many through-hole holdouts do we have out there?

Design for Modules Designing this into your PCB is easy

There are some cases where you can’t avoid tiny parts, or where the fabrication of the board itself really matters. In these cases, using already-built DIP modules can often help. This is fairly obvious for things like radio-frequency parts: high-frequency circuitry can be tricky so having a tested design for the radio part guarantees that it will work. As long as you’re not making a custom radio, designing in a module like an RFM69 for ISM bands, nRF24 for 2.4 GHz, an HC-05 for Bluetooth LE, or an ESP8266 for WiFi is probably the only reasonable choice in single units. They (and similar radio modules) are an amazing bargain considering the development time and effort they embody.

The same goes for wired connections. Things like the ENC28J60 Ethernet LAN module, and USB-serial adapters are also available about as cheaply in module format as the individual parts would be in small volumes. This is the economics of scale: I can buy a complete ENC28J60 module for less money than I can buy the chip, magnetics, and a crystal to run it. It’s no surprise that we see more designs incorporating these modules whole, versus re-building them from scratch.

CPU Modules Difficult home-etching vs Easy eBay ordering

The surprising exception to this rule is in the choice of microcontrollers. I’ll be the first to admit that I have a stable of favorite microcontrollers that I draw from depending on the features that I need — one that I like for its DAC, another that I like because it is fast, another because it has many SPI peripherals or USB and so on. I’ll buy these in sticks of 25 or so, where they’re cheap. I’ll make 25 projects eventually, or end up with half-full sticks cluttering up my closet.

For a one-off project, all of this is over-optimization and a waste of time, effort, and money. And if you want another hacker to reproduce your project, what matters is the single-piece cost and the ease of incorporating the microcontroller into the design. The design-for-hackers alternative is to settle on one of a couple of cheap microcontroller modules.

The “Blue Pill” and the “Pro Mini” Cloneduino

Everyone with access to eBay can get their hands on a pre-soldered ATmega328p or STM32F103 board with a crystal, power supply, and all of the pins broken out for just about the single-source cost of the microcontrollers themselves. There are, of course, a wide variety of modules out there, but the ubiquitous “Pro Mini” and “Nano” Arduino knockoffs and the Maple-mini clones shaped like a blue stick (search for “STM32F103C8T6”) are obvious choices from a price/performance perspective.

These modules, just like the RF or Ethernet modules, take a lot of the soldering and assembly work off the hacker reproducing the project in single-unit quantities. It’s a win all around. In my opinion, any project that specs an ATmega or STM32F10x chip by itself, rather than in the eBay-friendly module format, is doing the hacker a disservice.

The Cost of Modules

The downside of using modules is that you’re at the whim of the market. You can buy complete nine degree-of-freedom IMUs today for prices that were unheard of five years ago, even for the raw chips in quantity. But you don’t get your choice of IMU. You have to buy the most popular one, so there’s a design constraint.

The particular STM32 chip in the Maple Mini knock-offs is fairly old, and its peripheral set is limited relative to the entire lineup. It lacks the DAC of its newer brothers, for instance. But for the price of an outboard DAC and some SPI hookup, you can get both better output quality and reduce the soldering complexity for the DIY’er. That’s a win in my book.

The other, hidden, cost is that some of these modules can be flaky. I’ve personally received one bad STM32F103 “blue pill” board out of an order of five. Bad luck? Probably. But I’ll test the chips out before I solder them to my main board from now on. The upside of the pre-built module format is that this is very easy to do because it’s got all the programming and power pins already built in.

Conclusion

I’ve just scratched the surface of Design for Hackers, but the column’s already long enough. Next time, I’ll look into things like layout considerations, parts selection, and tricks to reduce BOM cost for single-unit manufacturing. Heck, maybe I’ll even begin to practice what I preach.

Until then, please leave your comments on your experience with (SMT) part sizes, board layering, and module use in other peoples’ projects. Include links to particularly good examples of best practices. What little touches have made your life easier? What design choices work for 100,000 quantities, but fail when translated to the DIY lab?


Filed under: Engineering, Featured, Microcontrollers, slider

Oscillating Pneumatic Mechanism Doesn’t Need a Purpose

พุธ, 07/27/2016 - 18:01

It’s true that a lot of the projects we feature here (and build ourselves) are created to accomplish some sort of goal. But, many times the project itself is the goal. That’s the case with [Proto_G’s] self-oscillating pneumatic machine, which he built with no particular use in mind.

[Proto_G] started this project simply as an engineering exercise; he just wanted to see if he could make it work. That’s the kind of spirit we find very admirable — not every project needs to be the culmination of your life’s work. Sometimes, just doing the thing is motivation enough.

Like any good engineer, [Proto_G] thinks mechanisms and linkages are neat. And, even Hollywood agrees that an oscillating mechanism is not a trivial design. Adding pneumatics to the mix just adds to the interest. The basic idea is to switch opposing valves on and off when the carriage reaches each side, which is accomplished with pneumatic actuators which trigger air pressure in a “magnetically coupled rodless cylinder.”

The magnetically coupled rodless cylinder is a pretty interesting component, which utilizes a magnetic piston within the cylinder to move the magnetically coupled carriage on the outside of the cylinder. This lets the piston work with pressure in both directions, as both sides are sealed. Could this have been accomplished in other ways? Sure, it could. But, this way is pretty darn cool, and is something you can add to your list of mechanisms that you might use in future projects.

[via /r/engineering]


Filed under: hardware

Robo Hobo Bamboozles Passers-By

พุธ, 07/27/2016 - 15:01

Robots are increasingly seeing the world outside of laboratories and factories, and most of us think we would be able to spot one relatively quickly. What if you walked past one on the street — would you recognize it for what it was? How long would it take for you to realize that homeless organ grinder was a robot?

The brainchild of [Fred Ables], Dirk the homeless robot will meander through a crowd, nodding at passers-by and occasionally — with a tilt of his hand — ask for change, churning out a few notes on his organ for those who oblige him. [Ables] controls Dirk’s interactions with others remotely from nearby, blending into the crowds that flock to see the lifelike automaton, selling the illusion that Dirk is a real human. This is often effective since — as with most homeless people — pedestrians won’t spare Dirk a second glance; the reactions of those who don’t pass him over range from confusion to anger or mirth over being so completely duped before looking for the puppeteer.

Tripling as a feat of engineering, a social commentary on homelessness, and an interactive puppet show, [Ables] causes us to pause on the issue of homelessness and human-robot interaction. For a more whimsical interaction, a robot ball that follows you around is a pleasant way to get used to the presence of robots in society.

[via setvir and Electric Circus]


Filed under: robots hacks

Hackaday Prize Entry: A Cheap Robotic Microscope

พุธ, 07/27/2016 - 12:00

The microscope is one of the most useful instruments for the biological sciences, but they are expensive. Lucky for us, a factory in China can turn out webcams and plastic lenses and sell them for pennies. That’s the idea behind Flypi – a cheap microscope for scientific experiments and diagnostics that’s based on the ever-popular Raspberry Pi.

Flypi is designed to be a simple scientific tool and educational device. With that comes the challenges of being very cheap and very capable. It’s based around a Raspberry Pi and the Pi camera, with the relevant software for taking snapshots, recording movies, and controlling a few different modules that extend the capabilities of this machine. These modules include a Peltier element to heat or cool the sample, a temperature sensor, RGB LED, LED ring, LED matrix, and a special blue LED for activating fluorescent molecules in a sample.

The brains behind the Flypi, [Andre Chagas], designed the Flypi to be cheap. He’s certainly managed that with a frame that is mostly 3D printed, and some surprisingly inexpensive electronics. Already the Flypi is doing real science, including tracking bugs wandering around a petri dish and fluorescence microscopy of a zebrafish’s heart. Not bad for a relatively simple tool, and a great entry for the Hackaday Prize.

The HackadayPrize2016 is Sponsored by:
Filed under: Raspberry Pi, The Hackaday Prize

Mergers and Acquisitions: Analog and Linear

พุธ, 07/27/2016 - 09:01

Analog Devices and Linear Technology have announced today they will combine forces to create a semiconductor company worth $30 Billion.

This news follows the very recent acquisition of ARM Holdings by Japan’s SoftBank, and the later mergers, purchases or acquisitions of On and Fairchild, Avago and Broadcom, NXP and Freescale, and Microchip and AtmelIntel and Altera, and a few more we’re forgetting at the moment.

Both Analog and Linear address similar markets; Analog Devices is best known for amps, interface, and power management ICs. Linear, likewise, isn’t known for ‘fun’ devices, but without their products the ‘fun’ components wouldn’t work. Because the product lines are so complimentary, the resulting company will stand to save $150 Million annually after the deal closes.

Analog and Linear are only the latest in a long line of semiconductor mergers and acquisitions, but it will certainly not be the last. The entire industry is consolidating, and the only way to grow is by teaming up with other companies. This leads the question if there will eventually only be one gigantic semiconductor company in the future. You’ll get different answers to that question from different people. Hughes, Fairchild, Convair, Douglas, McDonnell Douglas, North American, Grumman, Northrop, Northrop Grumman, Bell, Cessna, Schweizer and Sikorsky would say yes. Lockheed Martin and Boeing would say no. It’s the same thing.


Filed under: news

Pressure-formed Parabolic Mirror from a Mylar Blanket

พุธ, 07/27/2016 - 06:00

Parabolic reflectors are pretty handy devices. Whether you’re building a microwave antenna or a long-distance directional microphone, suitable commercial dishes aren’t that hard to come by. But a big, shiny mirror for your solar death-ray needs is another matter, which is where this pressure-formed space blanket mirror might come in handy.

Pressure-forming was a great choice for [NighthawkInLight]’s mirror. We’ve covered pressure-formed plastic domes before, and this process is similar. A sheet of PVC with a recessed air fitting forms the platen. The metallized Mylar space blanket, stretched across a wooden frame to pull out the wrinkles and folds, is applied to a circle of epoxy on the platen. After curing, a few puffs with a bicycle tire pump forms the curve and stretches the film even smoother. [NighthawkInLight]’s first attempt at supporting the film with spray foam insulation was a bust, but the later attempt with fiberglass mesh worked great. A little edge support for the resulting shiny taco shell and the mirror was capable of the required degree of destructive potential.

We doubt this process can be optimized enough to produce astronomy-grade mirrors for visible light, but it still has a lot of potential applications. Maybe a fiberglass radio astronomy dish could be pressure-formed directly with a rig like this?


Filed under: misc hacks

Ugly DIY Portable Soldering Iron

พุธ, 07/27/2016 - 03:00

If you’ve ever wanted a battery-operated soldering iron and you just can’t stand the thought of buying one, you might check out the video below from [Just5mins]. In it, he takes a candy tube, some scrap materials, a lithium ion battery, a nichrome wire, a USB charger, and a switch and turns it into an apparently practical soldering iron.

Paradoxically, [Just5mins] used a soldering iron to build this one, so it probably can’t be your only soldering iron, although we suppose you could figure something out in a pinch. Maybe in rep-rap style, make a poor quality one with no soldering and use it to solder up the next one.

This is an interesting little hack, but honestly, if you need a soldering iron this probably isn’t going to be your first choice. We suppose it is a little more practical than the cigarette lighter iron we saw earlier. If you are on a budget and want a USB soldering iron, we saw a review on those, too. Or, you could go with Solderdoodle.


Filed under: tool hacks