When we first got our Makerbot Replicator last year, I was really excited about the promise of using the dual-extrusion machine to make more complex prints. Why add a second print head? In the beginning, the ability to print multiple colors of plastic, without having to swap filament mid-print was compelling. And while I did manage to print a handful of test designs using black and white filament on the Replicator, the process to prepare models for a dual-head print involved splitting the different colored parts of a model into two separate STL files, making each of them printer-ready separately, merging them in ReplicatorG, and then adding a couple of additional steps to the already lengthy slicing process. It kind of sucked.

Enter MakerWare, Makerbot’s custom, mostly-closed source ReplicatorG replacement. While Makerware lacked dual-extrusion support at launch, it was added earlier this year. Since the update, I reconfigured our printer so it was running PLA on one head and ABS on the other—this makes printing using whichever material I want much more convenient. However, I hadn’t had a chance to test it out printing multiple colors on a single object using Makerware. I picked up a couple of fresh spools of ABS last weekend at MakerFaire, and figured that was as good an excuse as any to try dual-extrusion again.

My first multi-color attempt using Makerware was one of the gorgeous multi-color vases listed on Thingiverse (also pictured above). I set it up using the highest resolution setting, 0.1mm, which is what I usually use for prints today. Users of Makerware probably know that the Low and Medium print quality settings use MiracleGrue, Makerbot’s proprietary slicing engine, while the High quality setting uses ReplicatorG. MiracleGrue is dramatically faster than ReplicatorG, but it produces prints that are much lower quality (0.27mm vertical resolution vs. 0.1mm). I wanted to test both MiracleGrue and ReplicatorG with multi-color prints.

The difference in speed was quite remarkable. On my laptop, slicing the Julia vase took just under 8 hours to run using Makerware’s High quality setting and the ReplicatorG slicer. The slicing process converts a three-dimensional model into a series of layers that can then be translated into toolhead movements. This may seem like a relatively simple task, but it isn’t. The software has to take into account everything from the amount of plastic going into the print head to the mechanical properties of the hot plastic to the amount that it shrinks when it cools. To slice for a dual-extrusion printer, the software has to cut up slices for each color separately, weave the tool path commands together for each layer, and then check the tool path for potential crashes or other errors. The MiracleGrue slicer took about 10 minutes to do the same thing.

But wait, there’s a twist. Only the simplest of the multi-color objects I tried to print using the Miracle Grue slicer actually printed—the sample Makerbot tag that’s pictured above. The other objects failed in similar ways—each printed a portion of the first color of the first layer of the model, then stalled. This seems like it's probably a bug with the slicer. The ReplicatorG prints weren’t much better though, despite taking much longer to slice. Every time I tried to print the Julia vase, the filament going into the extruder head stripped at about the same place, a problem I haven't taken the time to figure out yet.

There is some good news though. I was able to get the cat pictured at the top of this post to print after spending a significant portion of the last three days. Unfortunately, the print finished too late to make him this week’s Mystery Object, so instead of a Mystery Object, he'll be an object lesson. If I’m going to try to do a dual-extrusion Mystery Object in the future, I need to start earlier in the week (or with something less complex).

The Gravity Gun from Half-Life 2 has always been one of my favorite video game guns, both in terms of design as well as use. It was always amazing to me that it took almost eight years for accomplished prop builders to take a crack at it, given how iconic both the weapon and the game are to the broader gaming community.

In December 2012, I decided to start on a build of it myself.

For the uninitiated, the Gravity Gun is one of the primary weapons and tools that you use in the video game Half-Life 2. It allows you to pick up and throw various objects in the game. You only get to see it from the 3rd person in a few instances, thankfully one of which is when another character in the game is holding it.

You can see the size of the weapon here, and I used this image to help determine the scale used when building everything. Coming from a 3D design background, my primary prototype building methods utilize laser cutting and 3D printed parts. Props from video games make the first steps easy, since in most cases you can easily extract a game model into a workable format. However there are a few caveats to this:

For a robot the size of a shoebox, OpenROV has made quite a splash in the submersible community in the past year. Just after MakerFaire 2012, where we saw OpenROV for the first time, it and its creator Eric Stackpole showed up in the New York Times along with a bold proclamation about the open source project: "It could change the future of ocean exploration."

Photo credit: NASA

Those weren't Stackpole's words, but you can bet he believes them--his quest for a sub-$1000 exploration bot recently landed him on the cover of Make Magazine, and OpenROV was back at this year's Maker Faire. Last August, Stackpole and his partner David Lang raised over $100,000 on Kickstarter for the OpenROV. What's surprising, considering how successful OpenROV was in 2012, is just how far the ROV has advanced in the past year.

"Even when we were doing that expedition to the Hall City Cave that ended up in the Times, we didn't really have a robot that was fully functional," says Stackpole at Maker Faire 2013. "You know, this is a maker product. It was on its way, there were some things that could work. We could drive it around, but the video feed wasn't reliable. Now we're at a point where we have everything we had dreamed of. Live video streaming, we can do high definition, it's going up to a computer. It's functional. This is the part where it really gets exciting. This is where we're going to start exploring, really exploring, places that haven't been seen before."

Photo credit: Make

Stackpole is a fountain of enthusiasm, but he's earnest when he says things like "this is the part where it really gets exciting," he means it. His obsession with ocean exploration came while he worked at NASA as a mechanical engineer, and last year he reduced his hours to devote more time to OpenROV.

Just in the past few months, the OpenROV project has made a major breakthrough.

This year’s Google I/O came and went without a new version of Android, and there was much griping on the internet. Even though Google isn’t required to announce anything of consumer interest at a developer event, the past few I/O conferences have made it clear this is Google’s big software show. Everyone watches and waits on the big reveal, but this year we got nothing--or did we?

While it may appear at first blush that Google I/O 2013 was a bust, it was actually an incredibly important step for Google. This is the event when Google finally beat fragmentation.

Why Wait?

If you paid close attention to the developer talks and API announcements, there were some enticing tidbits about the future of Android. For example, Google made it clear that Bluetooth Low Energy (AKA Bluetooth SMART) was coming to Android, but not under existing OS versions. No, this Bluetooth 4.0 implementation would be part of the platform in API level 18. Jelly Bean 4.2 is API level 17. There were also various server log and benchmark leaks -- the kind of stuff we always see when a new OS is imminent.

Hints like this indicate there is a newer version of Android that is far enough along that it has a finalized Bluetooth stack and is being tested on internal Google devices. Rumors can’t always be trusted, but the word is that Google was prepared to announce Android 4.3 at Google I/O, but decided to hold back and make a point. What point? Simply, Google doesn’t need a new version of Android to rollout new services to users.

Look at the Android announcements that did happen: Hangouts, Google Play Games, app data sync, Play Music All Access, and synced notifications. Those are neat features, but no one is going to convince Android fans it’s as sexy as a new version of the platform. However, the impact might be even greater than if Google had announced Android 4.3.

Imagine that Google had shown off a new version of Android; let’s even say that it was extremely impressive. After hearing the news, most Android users would look at their Galaxy S3 or Droid RAZR Maxx HD, and feel a mixture of annoyance and apathy. When Google announces a new version of Android, it only has an immediate effect on Nexus owners, which make up a small percentage of total Android users. The new services Google announced affect almost every Android phone in the world.

Phones running Gingerbread or higher got these new features. According to the latest platform numbers that’s nearly 95% of active Android devices. Google is proving that it can improve the Android experience without waiting for every OEM and carrier to get device updates deployed. That's worth a small delay.

It’s safe to say that Nvidia is really competing with itself at this point in time. The current GeForce GTX 680 is pretty much even in performance to AMD’s Radeon HD 7970 GHz Edition, but much quieter and uses less power. The GeForce Titan outperforms AMD’s single-GPU flagship by a wide margin, but costs a cool grand, so it’s out of reach of most users.

Enter the GeForce GTX 780. At first blush, it seems like a “Baby Titan”, but that would be inaccurate. Let’s look at the base specs, compared to both the Titan and the GTX 680.

Given that the GTX 780 uses the same GPU chip as the GTX Titan, but with roughly 15% fewer shader cores and half the memory, the GTX 780 offers about 80% of the gaming performance of a Titan, as we’ll see shortly. Take a look at that memory speed, too: 7000 MHz (effective), or 1gpbs faster throughput than the Titan or GTX 680. There’s no lack of memory bandwidth with the GTX 780. However, Nvidia told us that the GTX 780 would only have about a quarter of the double precision floating point performance of Titan. In other words, the GTX 780 will be a great gaming card, but won’t come close to Titan for high end GPU compute.

Digging a little deeper into the features of the GTX 780 card itself, Nvidia’s made some interesting design decisions in the reference design. The cooling subsystem is tweaked from Titan to run even quieter. Nvidia accomplished this by managing fan speeds to run closer to a steady state, rather than ramping the fan speeds up and down rapidly.

The GTX 780’s cooling system minimizes noise by keeping the average speed within a narrow band, avoiding fast spin rate ramps.

The GTX 780 will cost substantially less than a Titan, at about $649 for reference grade cards, but that's nearly $200 more than a 2GB GTX 680. However, 4GB GTX 680s still cost nearly $600, so the price differential between a GTX 780 and GTX 680 4GB card isn’t as large, while new new card offers quite a bit more performance. Still, $649 is a pretty steep price for a video card, and it’s partly a result of AMD’s inability to compete on single GPU performance. The lack of competition puts Nvidia in the enviable position of being able to set higher prices than they might have if competition had been stiffer. I included a GTX 680 4GB card for comparison, but it’s likely that performance differences with a 2GB card will be minor.

With this sobering thought in mind, let’s take a look at performance.

Recently, we’ve seen some buzz about Dolby Atmos, a relatively new movie theater sound technology that gives the illusion that there are an infinite number of audio speakers and channels surrounding the audience. It’s hard to believe we didn’t even have wide-spread Dolby Stereo in movies until Star Wars, and if theaters wanted to play Lucas’s space opera, they had to redo their sound system, or Fox wouldn’t give them the film reels.

Several years prior to Dolby Stereo, studios also experimented with a short-lived experiment in movie sound that’s fun to look back on today: Sensurround. It was a gimmick of its time, because the era of the all-star disaster film was in full swing, and while Sensurround wasn’t as high tech as Lucasfilm's THX or Dolby's Atmos, it did try to make movies feel bigger and more realistic through the sheer power of sound, and perhaps helped pave the way for today’s cinema audio technology.

Photo credit: Flickr user hijukal via Creative Commons.

Sensurround was the brainchild of the late Jennings Lang, a Hollywood producer who knew the power of showmanship. Lang was one of the first to call a film an “event” back in 1974 for Earthquake, and legend has it the idea for the film was based on a true event. Lang was in a movie theater when a real life earthquake happened. Then Lang got the idea about making a disaster film where an earthshaker hits L.A., and it would somehow shake the hell out of the audience as well.

“My dad was one of the last true showmen,” says his son, Rocky Lang. “He realized that movies had to be bigger and more event oriented. He was always trying to find a way to make the movie going experience bigger and better.”

"ATTENTION! This motion picture will be shown in the startling new multi-dimension of Sensurround. Please be aware that you will feel as well as see and hear realistic effects such as might be experienced in an actual earthquake. The management assumes no responsibility for the physical or emotional reactions of the individual viewer."- Theater Notice For Earthquake (1974)

By setting up a series of speakers in the theater, and running a soundtrack with very low tones, an earthquake simulation could be done, and there were cues on the Earthquake soundtrack when the special speakers were to be triggered.

It should only take two words to sell you on the idea of 3D printed food: "Pizza printer." Back in February we wrote about how 3D printers could be used to create the space foods of the future. Cornell's Fab@Home printer is already on the way, as it's able to build simple foods out of hydrocolloids. Of course, we're still a long way from the Star Trek Replicator, but even NASA's paying attention to the prospect of 3D printed food. The organization recently handed a $125,000 Small Business Innovation Research grant to Anjan Contractor to continue developing his prototype universal food synthesizer.

Star Trek's Food Replicator

Contractor's vision for 3D printed food is currently centered around space applications, but his eventual goal is to eliminate food waste here on Earth. "He sees a day when every kitchen has a 3D printer, and the earth’s 12 billion people feed themselves customized, nutritionally-appropriate meals synthesized one layer at a time, from cartridges of powder and oils they buy at the corner grocery store," writes Quartz. "Contractor’s vision would mean the end of food waste, because the powder his system will use is shelf-stable for up to 30 years, so that each cartridge, whether it contains sugars, complex carbohydrates, protein or some other basic building block, would be fully exhausted before being returned to the store."

The Small Business Research Innovation grant, though, is for a 3D printer that could supply food to astronauts on long trips. The International Space Station would welcome a food printer, most likely, but trips away from Earth's orbit, like a lunar colony or an expedition to Mars, would obviously benefit more. Powdered nutrients with 30 year shelf lives would be enormously valuable to astronauts setting up permanent shop on Mars.

And then, of course, there's the the pizza printer. Quartz writes "Contractor’s 'pizza printer' is still at the conceptual stage, and he will begin building it within two weeks. It works by first 'printing' a layer of dough, which is baked at the same time it’s printed, by a heated plate at the bottom of the printer. Then it lays down a tomato base, 'which is also stored in a powdered form, and then mixed with water and oil,' says Contractor. Finally, the pizza is topped with the delicious-sounding 'protein layer, which could come from any source, including animals, milk or plants."

Contractor won his grant thanks to his prototype 3D chocolate printer, seen above. It's not the only 3D printer we've seen lay down some chocolate goodness layer-by-layer, but it's the first we've seen that may lead to a 3D pizza printer. Godspeed, Anjan Contractor.

In 2012, Roy the Robot was one of the most eye-catching projects on exhibit in Maker Faire's expo hall. Half of Roy's draw came from his Terminator-like skeleton, with laser-cut wood standing in for shiny metal. He owed the rest of his appeal to a red Hawaiian shirt that Hunter S. Thompson and Bruce Campbell would've fought over. This year, the Hawaiian shirt hangs in the corner of Roy's booth, because he's no longer wearing it--he's got a brand new laser-cut chest to show off. 11 months after concluding a successful Kickstarter, maker Brian Roe is drawing a constant crowd to show off the new and improved Roy.

"At Maker Faire last year I had the arm and the hand and just the head, basically, the eyes and the jaw," says Roe, who's a mechanical engineer by day. "It was all mounted on a PVC frame kind of representing the shape of a human body, but nothing underneath the shirt. That's why he had a Hawaiian shirt on. I wanted to cover up all the PVC. This year I decided I really wanted to try to finish out the arms. So I got working on the arms, but then of course, if you're going to build the arms, they have to attach to something. So then you need the chest. Well, if I'm going to put the chest in there, I might as well do a cool neck because I've got the chest there to hook the neck to. So it got a little crazy. Now he sits with 48 servos, 16 servos in each arm. It's crazy. There's a ton of servos."

Roe started Roy as an animatronics project before Maker Faire 2012. The scale of the robot quickly spun out of control, but in a good way--Roe kept adding degrees of articulation, laser cutting parts in his home workshop, and suddenly his robot had a hand with individually servo-driven fingers. Roe launched a Kickstarter the first day of Maker Faire in 2012, offering Roy arm kits for backers to assemble, and eventually raised about $15,000--double his goal of $8,000.

There was enough money and interest in the project for Roy the Robot to grow even more complicated. But first, Roe had to deal with laser cutting some 10,000 parts for his backers.

The expo hall of Maker Faire is packed with hundreds of projects. Some Makers are there to sell things they've built. Others are just there to show off something fun. Craig Bonsignore, maker of the Open Clock, had a slightly different motivation for his project: He hated his alarm clock, so he built one of his own as a completely open source project. And every component, from the 6.4-inch resistive touchscreen to the 512 LED red/green display, is available online.

"It's the maker thing. Something bugs you, you just make a better one," says Bonsignore. "The design criteria were: Easy to use, easy to see, intuitive. I don't sleep with my glasses on, so with my glasses off, arm's length, I can read the digits without squinting."

The Open Clock looks a little like the time-telling equivalent of one of those cheap calculators with oversized buttons, and its numbers are big enough to read from across a room. But it's hardly a simple project. In his quest to make the perfect alarm clock--or, at least, an alarm clock that he won't hate--Bonsignore has given the Open Clock a fun array of features.

The display is touch-controlled, so a simple tap will switch from displaying the time to displaying the date. Another tap can open up the menu and adjust the time, and tapping at the top or bottom of a digit increases or decreases the number (if you've ever had one of those alarm clocks that makes you press a button 24 times to cycle through every AM/PM hour, you probably love this idea already).

The clock is green during the day from 7 o'clock in the morning to 7 o'clock at night, when it turns red.

"The clock is green during the day from 7 o'clock in the morning to 7 o'clock at night, when it turns red. So it's intuitive that right now it's day time, it's 1:52, it's green," says Bonsignore. He gestures to the three different models of the Open Clock he has on display at Maker Faire. A rough plastic frame houses the earliest model. "This is the first one--it's been sitting on my nightstand for about a year. I've sort of refined it over time. I think I started it with green at night, but decided, hey--red, submarines, there's kind of a night vision thing--red is better. You actually have more receptors on your retina for green. Green is an exciting color, and red is a subdued color, so that kind of made sense...The brightness adjusts automatically so it doesn't bug you at night. I had to go through some iteration on that."

The second Open Clock model has a smoother black shell. The third is made from transparent plastic, which shows off the Arduino board and speaker inside the clock. The LED face on the transparent model is also noticeably brighter than the other two, which he explains:

I've been reading a lot more about composition since writing my last column, since it's such a complex topic that's not very easy to verbalize. This has me going through old photo libraries, looking at ones that catch my eye, and wondering why a particular photo stands out. For example, one photo I really liked from last year is from New York Maker Faire, of the competitors in the Power Racing Series. Staring at a favorite photo you've taken to scrutinize its composition can be a maddening exercise, but those illuminating moments when you discover something new make the effort very worthwhile. And one of the things I'm becoming more aware of is the use of the ground in photography.

In reading up on composition, I came across several articles about the work of legendary French photographer Henri Cartier-Bresson. Cartier-Bresson is well known as the father of photojournalism and street photography, and New York-based photographer Adam Marelli has written some excellent analyses of Cartier-Bresson's compositional techniques. Among those tricks he mastered was the Figure-to-Ground relationship, a concept practiced in painting. Not surprising, since Cartier-Bresson began his career as an oil painter before adopting photography.

Let's first define our terms. In thinking about the relationship between Figure and Ground, the Figure represents the subject of a photograph. This can be a person, an animal, or even a smartphone. It's the most important object in the photograph--everything else serves to accentuate it or call attention to it. And that "everything else" is what's referred to as the Ground. The Ground is defined as everything that's not the Figure (or Figures), and the compositional relationship between those elements is the magic sauce that makes a photo stand out. The Ground of a photograph, as you can surmise, is actually short for background--but not necessarily in the spatial sense, since technically your subject could be in the focus in the background of a scene.

But while the real world exists in three dimensions, a photographic image is flat. And in a two-dimensional plane, there is no "background" and "foreground" in the spatial sense. So when I look through a viewfinder to compose an image, my mind has to "flatten" the scene in front of me, much like the flattening layers of a Photoshop file into one single image. In photography and painting, the physical ground becomes the background.

I've created a simple diorama to illustrate this concept:

Three months after Sony held a special event to announce the PlayStation 4, Microsoft responded with the announcement of the Xbox One. This is the follow-up to the Xbox 360, eight years down the road, and Microsoft's sticking with a familiar strategy: Dominate the living room. In the first 30 minutes of its Xbox One presentation, Microsoft focused more on the console's ability to switch seamlessly between live television, movies, music, and gaming than it did on games themselves. This is the definition of a do-everything box: in fact, Microsoft's combining its Windows 8 architecture and Xbox software into one unified experience.

Microsoft demonstrated that combination by showing off Windows 8's window snapping feature on the Xbox. While watching a movie, they brought up Skype on Xbox and snapped it to one side of the screen, allowing both movie and video chat to run simultaneously.

Through the first 30 minutes of its presentation, Microsoft quickly ran through the Xbox One's new hardware, new user interface, and new Xbox Live features. Everything has been changed and updated, including the Kinect and the controller. Thankfully, Wired has also taken a closer look at the Xbox One's hardware. Let's dig in.

The other day, I was talking to a friend about old tech we still use, and I realized I’d be hard pressed to find anything I’m still using that’s older than my studio headphones. I bought a pair of Sennheiser HD580s about ten years ago. They still sound great, but they’ve outlasted most of the other electronics I’ve purchased since then simply because the designers knew how they’d fail.

Most other headphones and earbuds I’ve had failed in exactly the same way—a cable gets damaged and the connection either breaks entirely or (worse) is sporadically noisy. Sure, it’s relatively easy to fix a broken wire, but the cable is never quite the same after you’re done—it’s thicker and is less flexible than an undamaged wire.

The good news for me is that I’ve never had to fix the cable on my HD580s, because they’re user-replaceable. At $25, the replacement cable is a fairly expensive part, but it takes a few seconds to replace the wires. And yes, the default cables are probably less sturdy than they should have been, but I’m happy to spend $25 every few years to avoid having to replace the headphones entirely. Over the last ten years, I’ve replaced the cables on my HD580s two or three times. The HD580’s foam parts, which tend to wear down over time, are user-replaceable too. They lasted longer than the cables, but I’ve replaced both when they wore out. The end result is that the headphones are just as comfortable and sound just as good today as they did when they were new.

I’ve probably clocked a few thousand hours on my HD580s over the last decade (including a couple of 24-hour marathons), and during that time I’ve killed a half-dozen pairs of earbuds. Everything from $20 generics to $125 Shures suffered my wrath. The only difference is that on the HD580s, I was able to replace the broken component. Unfortunately, since I bought these headphones, Sennheiser seems to have backed away from user-replaceable parts, at least for headphones in the $100-150 price range. Sennheiser’s much-more-expensive studio headphones still have user replaceable parts, but the more affordable HD5xx series doesn’t. It seems like the rest of the industry has followed suit. While The Wirecutter’s favorite sub-$150 headphones feature user-replaceable cups, the cord is a permanent fixture. Most of the other headphones in their roundup featured permanent cords.

Because the designers who built the HD580s knew where they’d fail and where they’d wear out, they made those components easily replaceable. There's a fine balance between planning well for failure and a planned obsolescence that results in a forced upgrade cycle. However, if the end result is that I can easily fix things that break due to normal wear and tear without having to replace them, I'm happy to keep using my HD580s for the foreseeable future—until they either break beyond my ability to fix or I can no longer buy replacement parts for them.

Here's a little behind-the-scenes detail for you. For this week's videos with Chris Hadfield (you've seen them by now, right?), Chris actually played cameraman himself for all the footage shot on the ISS. This was likely the case for his now-famous Space Oddity music video, which makes the feat that much more impressive. The video clips the Canadian Space Agency relayed to us were 720p video shot from on a Nikon DSLR, and while we were reviewing the footage, we noticed speckles of static white pixels throughout the video. It looked like dead pixels on our monitors, but they were actually damaged pixels on the ISS cameras!

The prosumer-grade cameras used on the International Space Station aren't heavily modified for use in space (they are certified through a rigorous testing process), so they actually aren't shielded from the cosmic radiation that exists both outside and inside the station. So when video is being recorded and the DSLR's mirror is flipped up, high-energy particles slam into the digital sensor and damage it permanently. According to astronaut Rex Walheim of STS-135, cameras that are taken on space walks may suffer severe radiation damage on sensor pixels. NASA evaluates the damage and decides whether or not to retire that camera for use.

Cosmic radiation (primarily gamma rays) are a well-known phenomenon for NASA and its astronauts. Some astronauts, including Neil Armstrong and Buzz Aldrin, have even reported seeing streaks of light that were determined to be cosmic rays zipping past their eyes. The most prolific astronaut photographer, Don Pettit, described the rays' effects on ISS equipment on his blog:

"Free from the protection offered by the atmosphere, cosmic rays bombard us within Space Station, penetrating the hull almost as if it was not there. They zap everything inside, causing such mischief as locking up our laptop computers and knocking pixels out of whack in our cameras. The computers recover with a reboot; the cameras suffer permanent damage. After about a year, the images they produce look like they are covered with electronic snow. Cosmic rays contribute most of the radiation dose received by Space Station crews. We have defined lifetime limits, after which you fly a desk for the rest of your career. No one has reached that dose level yet."

So rewatch our videos with Chris Hadfield and see if you can catch those speckles of damaged pixels--it's just another consideration that astronauts have to be mindful about when living on orbit!

We’ve now burned through a few gallons of very expensive silicone rubber to make molds of every one of the Halo Reach Needler prop's 12 individual parts. There are a bunch of Needler-shaped cavities that need to be filled with something, and in a similar theme to making the molds themselves, there’s a variety of ways to go about doing so.

Techniques and materials will vary depending on the final use of the piece, but for the purposes of this tutorial we’ll be concentrating on urethane casting resin and leaving out other plastics such as epoxy or polyester. I’ll cover solid casts, hollow parts, and translucent/clear pieces as well.

The most basic parts to be made will be the solid pour castings. For these parts I’ll be using Smooth-On’s product “Smooth Cast 320” and the detail bit that sits underneath the upper casing will be used as an example (apologies for the process photo, I didn’t have a shot of the completed master before molding.)

The initial step after removing your master part from the mold will be to apply a powder layer to all facing edges of the mold. Personally I use baby powder, but I have heard other propmakers use talcum as well. This may seem like an odd step, but this will help reduce bubbles in the finished part. You can think of the thin layer of powder like a paper towel over a spilled drink. Just like a napkin will wick up moisture, a thin coat of powder in your mold will allow the resin to flow more easily into detail edges. What you’re working against here is the surface tension of the liquid, which will have a more difficult time seeping into detail areas without this step.

Rather than risk losing your iPhone, we think a true waterproof camera or a GoPro or a waterproof camera is the best way to get photos in the water. But if you have to protect yours from impact, liquid and dust, the best tough waterproof iPhone case, overall, is the $80 Incipio Atlas.

We think the Incipio is the most well rounded phone case, more secure yet just as slim as last year’s favorite.

It has a depth rating of 6 feet, but was among the driest in our endurance pool tests when many others simply flooded. It even has a 1-year warranty against water damage to your phone.

But we also have a pick for a sport camera case to turn your smartphone into a quasi-GoPro action sports camera. And finally, I recommend a serious dive case for an iPhone that can go to over 100 feet of depth.

Why You Should Believe Us (and How We Tested)

My editor Brian Lam helped me test this case and the competition in Mexico and Indonesia, as well as the ocean and a pool in Hawaii. As an ocean exploration journalist and founder of the Wirecutter, I don’t think any technology writer is as equipped to test these cases as he is.

He lives in Honolulu and tested all of these cases by verifying their seals were dust free and by swimming a half mile in open water dragging them behind him and roughing them up up to 10 feet underwater during freedives. He also kept them in a pool overnight at six feet of depth, to challenge their seals over time–most cases are only rated for an hour at their given depth so this is a really great way to test minor design flaws that would expose them over time or keep them from going deeper than their rated spec in case you needed to drop down for a moment. He also tested the deep dive case on an expedition as a fellow with MacGillivray Freeman films in Indonesia, to 80 feet.

For non-water sports, ruggedness, shock absorbing designs and materials as well as build quality was factored in. For action sports camera cases, meant to take a smartphone and transform them into a GoPro kind of camera, things like accessories (mounting options) were also important.