Speed Run [James Bruton’s] Star Wars Builds

We’ve been following [James Bruton]’s builds here on Hackaday for quite a while and he has built some impressive stuff. We love how he often doesn’t cover everything up, leaving enough room to admire the working bits under the hood. Just in time for the release of the new Star Wars movie, Rogue One, [James] put together an overview of his Star Wars robot builds.

The build summary includes his R6 droid, his GNK walking droid and the third revision of his BB-8 droid. [James Bruton]’s videos have tons of detail in them over many, many parts (for example, his BB-8 R3 playlist is 15 parts and his Ultron build currently has 26 episodes and counting!)

There’s a quick overview of each of the three robot builds in this video, and it includes links to the playlists for each build for those who want more detail. This is just what you need to glimpse all of the clever design that went into these wonderfully crafted droids. And if you haven’t seen it yet, you should check out his series elastic actuators that he’s working on for the Ultron build, they give a robot some relief from rigidity.

Filed under: 3d Printer hacks, Arduino Hacks, robots hacks

Thermoelectric Paint Opens Prospect Of Easier Energy Harvesting

We will all be used to the thermoelectric effect in our electronic devices. The property of a junction of dissimilar conductors to either generate electricity from a difference in temperature (the Seebeck effect), or heating or cooling the junction (the Peltier effect). Every time we use a thermocouple or one of those mini beer fridges, we’re taking advantage of it.

Practical commercial thermoelectric arrays take the form of a grid of semiconductor junctions wired in series, with a cold side and a hot side. For a Peltier array the cold side drops in temperature and the hot side rises in response to applied electric current, while for a Seebeck array a current is generated in response to temperature difference between the two sides. They have several disadvantages though; they are not cheap, they are of a limited size, they can only be attached to flat surfaces, and they are only as good as their thermal bond can be made.

Researchers in Korea have produced an interesting development in this field that may offer significant improvements over the modules, they have published a paper describing a thermoelectric compound which can be painted on to a surface. The paint contains particles of bismuth telluride (Bi2Te3), and an energy density of up to 4mW per square centimetre is claimed.

This all sounds impressive, however as always there is a snag. The coating is painted on, but then it must be sintered at high temperature to form the final material. Then since the thermoelectric Seebeck effect voltage generated across a junction is tiny, some means must be arrived at to connect multiple regions of paint in series to achieve a usable voltage. The paint is produced in both n- and p-type semiconductor variants, so they appear to achieve this series connection by alternating bands of each. And finally the efficiency of the whole is only as good as the ability of its cold side to lose heat, so we are guessing to be effective it would require something extra to improve heat transfer away from it. Still, it will have a thermal bond with its substrate that is second to none and it has the potential to cover the entire surface of a hot item, so it shows considerable promise. The researchers discuss using it for power generation, but  we wonder whether there is also a
prospect of it being used as a Peltier effect device to provide enhanced cooling.

We’ve covered many conventional thermoelectric generators in the past. The smallest was probably this LED ring, but we’ve also shown you a thermoelectric charger for use in rural Mongolia, and this very neat candle-powered fan.

Thanks to [Jack Laidlaw].

Filed under: chemistry hacks, green hacks

A Handy Tutorial For Voice-Command Awesomeness

When somebody can’t find a guide on how to accomplish a particular task, we here at Hackaday admire those individuals who take it upon themselves to write one for the benefit of others. Instructables user [PatrickD126] couldn’t find a write-up on how to connect Amazon’s Alexa service, and Echo to his Raspberry Pi home security system, so his handy tutorial should get you up to speed for your own projects.

[PatrickD126] shows how loading some software onto the Raspberry Pi is readily accomplished along with enabling Alexa to communicate more directly with the Pi. From there, it’s a matter of configuring your Amazon Web Services account with your preferred voice commands, as well as which GPIO pins you’d like to access. Done! [PatrickD126] notes that the instructions in the guide only result in a temporary solution, but suggests alternatives that would allow your project to operate long-term.

For more advanced users this tutorial is probably rote, but it could save time in a crunch or hackathon scenario. Now all you have to do is connect this project to a typewriter that will allow you to dictate your next report — old school style.

[Thanks for the submission, Patrick D!]

Filed under: Raspberry Pi

LEGO Strain Wave Gear is Easy on the Eyes

We are continually amazed by the things people do with LEGO and Technics, especially those that require incredible engineering skill. There’s an entire community based around building Great Ball Contraptions, which are LEGO Rube Goldberg machines that move tiny basketballs and soccer balls from one place to another. Except for a few rules about the input and output, the GBC horizons are boundless.

Famed GBC creator [Akiyuki] recently built a GBC module that’s designed to show the movement of strain wave gear systems. These types of gear systems are used in industrial applications where precision is vital. Strain wave gears are capable of reducing gear ratios in a small footprint.

There are three parts to a strain wave gear: the wave generator, the flex spline, and the circular spline. [Akiyuki]’s wave generator is the elliptical gray disk in the center. It is attached to the input shaft. The flex spline is the piece around the gray disk that is transporting the little balls. It is called a flex spline because the wave generator forces it to flex into an ellipse. Industrial strain wave gears are of course made of metal, and the flex spline does not get quite as deformed by the wave generator as this one. The 1/8 reduction ratio also exaggerates the deformation.

We covered one of [Akiyuki]’s larger GBCs a few years ago. While that one is definitely impressive, this strain wave gearing module is quite the engineering marvel.

Continue reading

Maybe You Can Print in Metal

Let’s face it. Printing in plastic is old hat. It is fun. It is useful. But it isn’t really all that exotic anymore. The real dream is to print using metal. There are printers that handle metal in different ways, but they aren’t usually practical for the conventional hacker. Even a “cheap” metal printer costs over $100,000. But there are ways you can almost get there with a pretty garden-variety printer.

There’s no shortage of people mixing things into PLA filament. If you have a metal hot end and don’t mind wearing out nozzles, you can get PLA filament with various percentages of metal powder in it. You can get filament that is 50% to 85% metal and produce things that almost seem like they are made from metals.

[Beau Jackson] recently had a chance to experiment with a metal-bearing filament that has a unique twist. Virtual Foundry’s Filamet has about 10% PLA. The remaining material is copper. Not only do you have to print the material hot, but you have to print it slow (it is much denser than standard PLA). If it were just nearly 90% metal, that would be impressive, but nothing too exciting.  The real interesting part is what you can do after the print is complete. (If you don’t want to read, you can always skip to the videos, below.)

If you do nothing, you still wind up with a metal-like print. If you have access to a kiln, though, you can put  your part in at nearly 1000 degrees C along with the company’s proprietary “magic black powder.” This removes nearly all the PLA and leaves a completely (99.9%) metal object.

If you prefer, you can also sand and polish the material to bring out the metal appearance, which might be easier than slaving over a hot kiln. Either way, the results do look (and sound) like metal.

The company claims other metals are in development. This isn’t quite as awesome as having a printer that really spews molten metal, but it is a lot more affordable. Not that it is very cheap, mind you. A 750 g spool of material is $85. Sure beats electroplating, though.

 

Filed under: 3d Printer hacks

This DIY Wearable Assist Goes Beyond Traditional Therapy

Bodo Hoenen and his family had an incredible scare. His daughter, Lorelei, suddenly became ill and quickly went from a happy and healthy girl to one fighting just to breathe and unable to move her own body. The culprit was elevated brain and spinal pressure due to a condition called AFM. This is a rare polio-like condition which is very serious, often fatal. Fortunately, Lorelei is doing much better. But this health crisis resulted in nearly complete paralysis of her left upper arm.

Taking an active role in the health of your child is instinctual with parents. Bodo’s family worked with health professionals to develop therapies to help rehabilitate Lorelei’s arm. But researching the problem showed that success in this area is very rare. So like any good hacker he set out to see if they could go beyond the traditional to build something to increase Lorelei’s odds.

What resulted is a wearable prosthesis which assists elbow movement by detecting the weak signals from her bicep and tricep to control an actuator which moves her arm. Help came in from all over the world during the prototyping process and the project, which was the topic of Bodo Hoenen’s talk at the Hackaday SuperConference, is still ongoing. Check that out below and the join us after the break for more details.

The core concept is to provide assistive feedback which will help Loreli’s body get better at relearning how to command her affected bicep and tricep.

Challenges

There’s a hard limit on weight for this project. That’s because too much weigh on the shoulder and it can be pulled out of the socket due to the current weakness. Hopefully this will also improve with time, but for now the assistive device needs to weigh less than 150 grams.

The actuator must be able to move the mass of her forearm (about 400 g). Input should come from the bicep and tricep using electromyography. They also want a relatively long battery life of at least five hours, and for the final product to look nice, lest she not want to wear it.

No Prior Experience

How do you build something with no prior experience? For regular Hackaday readers that’s not a real question… we do it all the time. Bodo didn’t have experience with most of what went into this project, but cites his entrepreneurial experiences in tackling hard problems. The trick is to learn what it is you don’t know and then ask for help in those areas when needed.

What we really like is that he didn’t just build this for her but built it along with her. The two of them started researching what kind of things other people had built: how people were taking muscle signals and using them to move things. They came up with some ideas, when hitting road blocks they asked for help and the world responded.

3d-printing-and-moldingThey received help in learning how to 3D scan Lorelei’s arm for the
best fit. A company in Canada sent them some actuators that met their weight, size, and power constraints. When they tested out the EMG sensors they discovered the signals on her damaged arm were almost completely lost in the noise. Again, help came in from a company working on a very similar problem. A new seventeen-sensor method was adopted that uses machine learning to find those signals. Most recently they have turned this into a video game — Lorelei is retraining her body by moving an arm onscreen. Gamification of physical rehab? Yes please!

The physical prototype is moving right along. It was first assembled with Fischer Technik. With that proof in hand they 3D printed a lattice out of PLA. This was designed from the 3D scan of her arm, printed flat, then submerged in boiling water to soften it before being molded to a full-sized cast of her arm. The result is visually pleasing, light weight, sturdy, and well-fit to her arm.

It is very rare that children who have loss of muscle control from this condition are able to gain it back. But some progress has already been made. We think it’s amazing to see an outpouring of goodwill to help Bodo and his daughter in this endeavor and it has far-reaching benefits. She is learning a lot about engineering and what is possible in life. And they have built an example for others to follow when they are met with obstacles they need to overcome.

Filed under: cons, Hackaday Columns, Medical hacks

Creating A PCB In Everything: KiCad, Part 2

This is the continuation of a series where I create a PCB in every software suite imaginable. Last week, I took a look at KiCad, made the schematic representation for a component, and made a schematic for the standard reference PCB I’ve been using for these tutorials. Now it’s time to take that schematic, assign footprints to parts, and design a circuit board.

The completed schematic for our board
The completed schematic for our board

All PCB design tools have different methods of associating the schematic view of a component with how it will be represented on the finished board. Eagle uses libraries that contain both a schematic view and PCB view of a component. In the prehistory of PCB design software, Autotrax simply ignored the schematic view.

Click this button to run PCBnew
Click this button to run PCBnew

KiCad has a clear separation between a symbol (the schematic view) and a footprint (the PCB view). If we were to take our schematic and create a new PCB by running PCBnew, nothing would happen – our symbols aren’t associated with any footprints.

Click this button to run CvPCB
Click this button to run CvPCB

To associate symbols with footprints, we need to run CvPCB. This sub-program tucked inside KiCad gives us the ability to associate footprints with our schematic symbols.

cvpcbview
CvPCB, with another window open allowing you to view the footprints

It’s like the cloud, only not completely worthless

CvPCB is a new feature for KiCad 4.0. Instead of every other PCB design tool we’ve taken a look at so far, KiCad effectively stores all of the footprints in Github. In the Github repo for KiCad, you’ll find a bunch of files with a .pretty file name. These are the footprints for nearly every component you can imagine. If you’re running a fresh install of KiCad, everything shows up in CvPCB automagically – there’s nothing you need to worry about, and footprints just happen.

There’s a subtle brilliance about this implementation. It’s like the cloud, only it’s completely verifiable, and if a part doesn’t work, you can fix it and submit a pull request. Already, this is phenomenally better than the Eagle paradigm, where millions of footprints are available in thousands of different libraries scattered around the Internet. If you’re reading through this series in order, take note: this ‘Github as the cloud’ will be a major point of comparison when we get to other cloud-based PCB design tools.

viewfootprintWith that said, we need to associate footprints with the symbols on our schematic. To do that, go down the list in the center of the CvPCB window that contains a list of all the components in our schematic and associate a footprint with each part. Footprints are on the right, libraries (or categories) are on the left. To view the selected footprint in a new window, click the ‘view selected footprint’ button.

selecting
Selecting a footprint for the USB port

Getting Libraries In Order

The footprint editor window
The footprint editor, found in the launcher

This project is using (mostly) all through-hole parts, and as such, I could easily select a DIP8 footprint for the ATtiny85 and be done with the whole thing. This is a tutorial, though, and I need to demonstrate how to make a part – schematic and PCB view – from scratch.

To make a footprint, KiCad offers a Footprint Editor. This can be accessed from either PCBnew or the launcher. Click on that, select File -> New Footprint, enter a name for this footprint (‘ATtiny85’ will do), the name of the footprint and a reference designator is placed onto the footprint editing window.

selectfplbLibraries are important, and since KiCad is now running on ‘not-worthless cloud technology’, we have to create a library for this project that won’t be saved along with our copies of the standard Github libraries. Select File -> Save Footprint In New Library, save this library wherever the rest of the files are for this project, and give the library a name.

We have just created a new library, but that doesn’t mean KiCad knows what library we’re working with. In the Footprint Editor, select Preferences -> Footprint Libraries Manager, and click on the ‘Project Specific Libraries’ tab. Hit the ‘Append Library’ button, and drop the path to the library we just created in the ‘Library Path’ field. That’s more KiCad weirdness, but once we’re done we can finally create a footprint.

library-table

Making The Footprint

Now that we have the Footprint Editor open, a part name and a reference for the footprint, and the library all set up, it’s time to actually put some pads down. There are a few relevant buttons on the screen:

Add a pad
Add a line
Add an arc
Add a circle

The most important, obviously, is the ‘Add a pad’ button. Click that and drop some pads down where they should be. This is a standard DIP8, or two rows of four pins 0.3″ apart. The default grid, as you may have noticed, is 50mils.

padproperties
footprintdone

After placing the pads, use the hotkey ‘E’ to edit the properties of each pad. Here, you can change a through-hole part to an SMD, change the dimensions of the pad, hole, and shape of everything. Importantly, the Pad Properties window allows you to change the number of the pad. The number of the pad is how KiCad connects the schematic representation of a part with the footprint. Get this right, or else nothing will work.

Add a few lines to the footprint, save your work in the project library, and go back to the schematic. You’re done. That’s how you make a footprint.

From Schematic To Board

Now that the schematic has footprints associated to everything, it’s time to open up PCBnew, move parts around, and put some traces between parts. Do that. Oh, nothing shows up. Why is that? You need to generate a netlist in the schematic view, and import it in PCBnew. There’s a button with ‘NET’ written on it in both programs. Click those. Now, what do we get when the netlist is successfully imported into PCBnew? The worst mess you’ve ever seen in any sort of design program:

This is fine.
I desperately want to see someone import a netlist for a large project in KiCad.

movemodeWe end up with a gigantic mess on our hands. No worries, ‘M’ is the hotkey to move the parts around. You can also use the ‘Move Footprint’ mode to automagically place these parts. Reference the PCB we designed for the introduction to this series and move some parts around until we get something resembling the board below. The relevant hokeys are
‘M’ for move and ‘R’ for rotate. As always, there’s the ‘?’ hotkey that tells you everything you need to know.

layout1

That’s close, but it looks horrible. Deselect Footprint mode, use your cursor, and move all those labels and references around. We don’t need “CONN-01×04” on the board, and it’s really helpful to have the values of resistors inside their own footprint. With a little bit of work and deleting those labels, you’ll have something that looks like this:

layout2

Holy crap, that actually looks like something. All the resistors and diodes are labeled with their value, all the superfluous references are gone, and this actually looks good. You can’t do this in Eagle easily.

layersWith the layout pretty much figured out, it’s time to finally draw some traces. This requires a description of the layers.

  • F.Cu and B.Cu are the top and bottom copper layers. The hotkeys for these layers are PgUp and PgDn
  • Edge.Cuts is the equivalent of the ‘Milling’ layer in Eagle. This is the outline of your board.
  • F.SilkS and B.SilkS is the silkscreen – the text and outlines of your components.
  • F.Mask and B.Mask is the soldermask. It’s usually green, or purple from OSHPark.
  • F.Adhes and B.Adhes is glue applied to SMD components.
  • F.Paste and B.Paste is where solder paste will be applied.

For a simple board that won’t be sent off to an assembly house, the only layers you need to worry about are the copper layers, the Edge.Cuts, and the silkscreen.

The first thing to do to complete the board is to draw the ‘edge’ or milling layer. Select the ‘Add a graphic line’ button on the right hand toolbar, and draw a rectangle around all our parts. That’s simple enough.

Now it’s time to actually put some traces down. You can select which copper layer to use in the top toolbar, and the relevant hotkey is ‘X’. Hit ‘X’, click on a few airwires, and route them just like the reference PCB. Don’t worry about power or ground traces – we’re going to do those with copper fills. When you’re done, you should have something like this:

layout3

filledzoneThat’s pretty much all there is to it, save for the copper fills. To do that, we need to add a ‘filled zone’ or ‘copper pour’ or a ‘polygon’. By any other name, it’s just a big area of copper that is connected to a single net in the schematic.

Click on the ‘Add filled zones’ button, and a ‘Copper Zone Properties’ window will show up. Here, you can assign a layer of copper to a specific signal. Our board puts +5V on the back copper, and GND on the front copper. In the Copper Zone Properties, select the B.Cu layer, the +5V net, hit Ok, and trace around the edge of the board. Do the same with the F.Cu layer and the GND net. When those fills become hatches around the edges of the board, hit the ‘B’ hotkey to render the copper fills.

layout4
copperzoneprop

That’s it. We are technically done. If you save and drag the .kicad_pcb file onto the OSHPark web page you’ll get a pretty purple PCB in a week or two. That’s not to say this PCB actually works – I screwed up the USB signals in the schematic, and that propagated over to the PCB. No matter, because no one is actually going to build one of these boards.

This just about concludes the ‘Creating A PCB in Everything’ tutorial for KiCad. If you’ve been reading along for the last five thousand words, you have an excellent introduction to KiCad, and should at least be able to build a breakout board. This doesn’t mean I’m done with KiCad quite yet – there are a few more tricks to go over including DRC and ERC, a demo of how freakin’ awesome the routing in KiCad is, and I need to put a keepout on the decoupling cap in on the board, anyway. Creating a PCB in Everything: KiCad Part 3 (the optional part) will be out sometime next week.

Thoughts on KiCad

This series of posts serves two purposes. First, it is a quick tutorial for various PCB design tools. After reading these posts, you should be able to guess your way through a PCB design tool and build a simple PCB. Second, each of these tutorials serves as a pseudo-review of each PCB design tool. Each of these posts serves to illuminate the quirks of a PCB design tool, and serves as a notice that I still have an unclaimed bounty for the first person to create a part for an ATtiny85 from scratch in Fritzing. Don’t use Fritzing, it sucks.

Coming from Eagle, KiCad is downright weird. That’s not to say it’s difficult, though – it’s generally the same as any other PCB design tool. The interface, like nearly every Open Source project, is obtuse, and there are five non-obvious ways to complete any task. There is zero reason why parts imported from a netlist into a board are squished together. Custom libraries can and should be automatically imported. The KiCad community especially rancorous. The UI suffers from an intangible wrongness about it, although that seems to lessen after working with it for a few hours. In a sense, KiCad is exactly what you would expect from an Open Source project that is decades old, very mature, and has features packed to the gills: it’s very powerful, but not friendly to the beginner.

Although the KiCad beginner will struggle to wrap their heads around the interface, it will be one of the most powerful PCB design tools I’ll use in this series of posts. No other free (beer) program will give you 32 copper layers and unlimited routing space. Nothing else uses the cloud/GitHub like KiCad. It’s brilliant.

A few months ago, if someone asked me to suggest a PCB design tool, I’d give Eagle or KiCad as suggestions. Eagle is easy enough to learn, and will be getting better since the Autodesk acquisition. KiCad is robust, and even in the best case of Eagle development, Autodesk may only ever reach parity with what KiCad can do.

Now, KiCad is growing on me. I have a secret project where I need to build and manufacture a thousand relatively complex boards. My previous go-to was Eagle, but I think I’m going to do this board in KiCad.

Filed under: Hackaday Columns, how-to, Skills

RainCube Spreads Its Umbrella

There are times when a mechanism comes to your attention that you have to watch time and time again, to study its intricacies and marvel at the skill of its designer. Sometimes it can be a complex mechanism such as a musical automaton or a mechanical loom, but other times it can be a device whose apparent simplicity hides its underlying cleverness. Such a moment came for us today, and it’s one we have to share with you.

RainCube is a satellite, as its name suggests in the CubeSat form factor and carrying radar instruments to study Earthly precipitation. One of the demands of its radar system is a parabolic dish antenna, and even at its 37.5 GHz  that antenna needs to be significantly larger than its 6U CubeSat chassis.

The unfolding parabola in action.
The unfolding parabola in action.

It is the JPL engineers’ solution to this problem that is the beautiful mechanism we want to show you. The parabola is folded within itself and tightly furled round the feedhorn within the body of the satellite. As the feedhorn emerges, first the inner sections unfurl and then the outer edge of the parabola springs out to form the dish antenna shape. Simultaneously a mechanism of simplicity, cleverness, and beauty, one we’d be very proud of if it were our creation.

There is nothing new in collapsible parabolas used in spacecraft antennas, petal and umbrella-like designs have been a feature of some of the most famous craft. But the way that this one has been fitted into such a small space (and so elegantly) makes it special, we hope you’ll agree.

[via space.com]

Filed under: radio hacks

Lightroom CC 2015.8 and Lightroom 6.8

Improves image editing responsiveness when background tasks are running ($149 new or $9.99 monthly Creative Cloud subscription, free update)

 

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DirecTV Now Joins the Scrum of Cord-Cutting TV Services

AT&T, via its DirecTV arm, joins the likes of PlayStation Vue and Sling TV with a TV streaming service that has cable-like offerings but is delivered entirely online. DirecTV Now works with the Apple TV, iOS devices, and the Mac, too.

 

Read the full article at TidBITS, the oldest continuously published technology publication on the Internet. To get a full-text RSS feed, help support our work and become a TidBITS member! Members also enjoy an ad-free version of our Web site, email delivery of individual articles, the ability to make long comments with live links, and discounts on Take Control orders and other Apple-related products.