Mirror, Mirror, On Your Cam, Show Us What You’ve Drawn By Hand

Working and learning from home may be the new norm, and if IKEA shelves are any indication, folks are tricking out their home office with furniture, gadgets, and squishy chairs. While teleconferencing has proven to be an invaluable tool, paper documents aren’t going down with out a fight.

Unfortunately dedicated document cameras require significant space and monies, so they’re impractical if you only share once in a while. [John Umekubo] didn’t want students and teachers hobbled by the same costs and inconveniences, so he modeled a mirror holder that slides over a laptop’s webcam and directs the view downward.

[John]’s adventures started with a Twitter post, as seen below, but the responses were so encouraging that he published his design on Thingiverse for everyone. There’s also a version that can be laser cut out of cardboard, though we imagine a pair of scissors would work in a pinch. He admits there’s already a consumer model, but wasn’t planning to sell them anyway. Like us, he wants to get people to share their work.

We recently covered a simpler version of the same idea in use at Northwestern University, and we’ve seen a similar hack that gives a split-screen effect to sketch and maintain eye contact. If you want to share the view in your room, we have a Raspberry Pi streaming option that’s worth checking out.

Continue reading “Mirror, Mirror, On Your Cam, Show Us What You’ve Drawn By Hand”

The Egg-laying Wool-Milk Pig

Last week, I wrote about two recent projects of mine that serve as cautionary tales in keeping projects simple — you probably can’t simplify everything, so it’s worth the time to find out which simplifications have the most bang for the buck. This week, I’d like to share a tale of lack of design focus.

German has the eierlegende Wollmilchsau: a mystical animal that lays eggs, while producing wool, milk, and meat to boot. It’s a little bit like the English “jack of all trades, master of none” except that the eierlegende Wollmilchsau doesn’t do each job badly, it plainly can’t exist. This is obviously a bad way to start a design.

The first surfboard that I made by myself was supposed to be an eierlegende Wollmilchsau. It was going to be a longboard, because we had months with smaller waves that just weren’t all that suitable for shortboarding, but it was also going to turn sharply off the rails like a shortboard. To help it turn, it was going to have tons of camber (bend like a banana), and small fins. And along the way, I thought I’d make it thin to cut through the water.

Of course what I ended up with, not helped by my heavy fiberglassing hand, was a plow that dug into the water, would turn unexpectedly when you managed to get it onto the rails, and couldn’t pick up a small wave to save its life due to the camber and aforementioned plowing. I surfed it anyway, as a matter of pride, but I had no illusions of it being anything but the the worst board I owned. And that’s comparing it to the $30 used rasta-graphic plank that had been taking on water for at least five years, unrepaired, and was rotting out from the inside. At least it had design focus.

My surfboard didn’t suffer from feature creep, where you start piling on features until the project crumbles from overload, but rather from wanting to have my cake and eat it too. Or from failing to realize that certain design goals were necessarily tradeoffs. The “raily” behavior that I wanted when it was in bigger waves was necessarily “diggy” in small waves. Good boards trade off these features, and getting the balance between them is the art of shaping a board.

So when you start up a new project, think about which facets of your design are jointly achievable, and which are necessarily tradeoffs. Ignoring tradeoffs is a recipe for disaster, designing an eierlegende Wollmilchsau. But viewed constructively, it’s exactly these nuanced decisions that separates the simply possible from the truly marvelous. May you identify your trades, and make them well!

Keep It Simple, Smartly

“Keep it simple” sounds like such good advice, but what exactly is the “it”; what parts of a project should you try to keep simple? You can’t always make everything simple, can you? Are all kinds of “simplicity” equally valuable, or are there aspects of a design where simplicity has multiplier effects on the rest of the project?

I ran into two seemingly different, but surprisingly similar, design problems in the last couple weeks, and I realized that focusing on keeping one aspect of the project simple had a multiplier effect on the rest — simplifying the right part of the problem made everything drastically easier.

EA Axon Great plane, but heavy!

The first example was a scratch-built airplane design. I’d made a few planes over the summer, focusing on plans on the Interwebs that emphasize simplicity of the actual build. Consequently, the planes were a bit heavy, maybe not entirely aerodynamic, and probably underpowered. And this is because the effort you expend building the plane doesn’t fundamentally have anything to do with flight. Keeping the build simple doesn’t necessarily get you a good plane.

Weight, on the other hand, is central. Wings produce lift, whether measured in grams or ounces, and anything heavier just isn’t gonna fly. But reducing weight has a multiplier effect. Less weight means smaller and lighter motors and batteries. Structures don’t need to be as stiff if they’re not subject to heavier bending forces. And, important to the noob pilot, planes with less weight per wing area fly slower, giving me (ahem, the noob pilot) more reaction time when something goes sideways. Trying to simplify the design by trimming weight has knock-on effects all around.

My latest fully-DIY design threw out anything that brought weight along with it, including some parts I thought were necessary for stiffness or crash resistance. But with the significantly lowered weight, these problems evaporated without needing me to solve them — in a way, the complexity of design was creating the problems that the complexity of design was supposed to solve. Ditching it meant that I had a slow plane, with simple-to-build wings, that’s capable of carrying a lightweight FPV camera. Done and done! Simply.

Nope. Too complex.

At the same time, I’m building a four-axis CNC foam cutter. I’ve built many 3D printers, and played around with other folks’ DIY CNC machines, so I had a few design ideas in my head starting out. My first iteration of an XY axis for the machine runs on metal angle stock with a whopping eight skate bearings per axis. It’s strong and rigid, and clumsy and overkill, in a bad way for this machine.

3D printers want to move a relatively light tool head around a small volume, but relatively quickly. CNC mills need to be extremely rigid and shoulder heavy side loads, subject to some speed constraints. A foam cutter has none of these needs. The hot wire melts the foam by radiation, so there are no loads on the machine because it doesn’t even contact the workpiece. And because it cuts by melting, it has to go slow. These are the places in the design where simplification will bear the most fruit.

I write this in retrospect, or at least from the perspective of a second prototype. I wanted the first design to hold the cutting filament taut, hence the rigid frame. But separating the tension from the motion, by using a lightweight external bow to keep the filament tight, meant that the machine could be dead simple. I could use smaller plastic sliders instead of complex bearings, on thin rods instead of bulky rails. In a day after having this realization, I got twice as far as I had on the previous machine design in a week, and it takes up a lot less space in my basement.

So take your KISS to the next level. Brainstorm a while about the binding constraints on your design, and what relaxing any of them can do. Do any particular simplifications enable further simplifications? Those are the ones that you want to start with. Keep it simple, smartly. And because it’s not always easy to find these multiplier effects, tell your friends!

Books You Should Read: The Design Of Everyday Things

With everything from APIs to Raspberry Pis making it even easier for us to create and share objects shaped by personal whim, it’s high time that Don Norman’s sage design advice falls on not just the design student, but the hardware hacker and DIY enthusiast too. Grab yourself a coffee and a free weekend, and settle into the psychology of people-struggling-how-to-use-that-widget-they-just-purchased in The Design of Everyday Things: Revised and Expanded Edition.

Who’s to blame for a door that opens with a pull when everything about how it looks says it should open with a push? In Don Norman’s world, it’s not you; its the designer. Enter a world where blame is inverted and mistakes can be critically categorized. Norman takes us example by example showing us how common items in the world poorly serve the needs of their user, mainly because the designer simply ignores key aspects of our humanity. This book is a crisp, concise overview of human psychology when applied to engaging with things combined with a language of ideas to help us apply this psychology to better interactions. (And it reads like butter!)

Opening Up to the Language of Design

What’s an affordance, you might ask? Well, simply put, it’s a way that an object can be used by a human. How about a signifier? That’s a communication “signposting” scheme that object uses to suggest to you how it should be used. If that sounds a bit fluffy, just think about the last time you tried to push open a door that needed to be pulled. Something about that door was suggesting that you could push it open, but it couldn’t! It “fooled” you because all the object’s signifiers were telling you otherwise. Continue reading “Books You Should Read: The Design Of Everyday Things”

2020 Hackaday Prize Hack Chat With Majenta Strongheart

Join us on Wednesday, May 27 at noon Pacific for the 2020 Hackaday Prize Hack Chat with Majenta Strongheart!

It hardly seems possible, but the Hackaday Prize, the world’s greatest hardware design contest, is once more at hand. But the world of 2020 is vastly different than it was last year, and the challenges we all suddenly face have become both more numerous and more acute as a result. We’ve seen hackers rise to the challenges presented by the events of the last few months in unexpected ways, coming up with imaginative solutions and pressing the limits of what’s possible. What this community can do when it is faced with a real challenge is inspiring.

Now it’s time to take that momentum and apply it to some of the other problems the world is facing. For the 2020 Hackaday Prize, we’re asking you to throw your creativity at challenges in conservation, disaster response, assistive technology, and renewable resources. We’ve teamed up with leading non-profits in those areas, each of which has specific challenges they need you to address.

With $200,000 in prize money at stake, we’re sure you’re going to want to step up to the challenge. To help get you started, Majenta Strongheart, Head of Design and Partnerships at Supplyframe, will drop by the Hack Chat with all the details on the 2020 Hackaday Prize. Come prepared to pick her brain on what needs doing and how best to tackle the problems that the Prize is trying to address. And find out about all the extras, like the “Dream Team” microgrants, the wild card prize, and the community picks.

join-hack-chatOur Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, May 27 at 12:00 PM Pacific time. If time zones have got you down, we have a handy time zone converter.

Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io. You don’t have to wait until Wednesday; join whenever you want and you can see what the community is talking about.

Peek At The Off-Ear Speaker Prototypes For Valve’s VR

The Valve Index VR headset incorporates a number of innovations, one of which is the distinctive off-ear speakers instead of headphones or earbuds. [Emily Ridgway] of Valve shared the design and evolution of this unusual system in a deep dive into the elements of the Index headset. [Emily] explains exactly what they were trying to achieve, how they determined what was and wasn’t important to deliver good sound in a VR environment, and what they were able to accomplish.

First prototype, a proof-of-concept that validated the basic idea and benefits of off-ear audio delivery.

Early research showed that audio was extremely important to providing a person with a good sense of immersion in a VR environment, but delivering a VR-optimized audio experience involved quite a few interesting problems that were not solved with the usual solutions of headphones or earbuds. Headphones and earbuds are optimized to deliver music and entertainment sounds, and it turns out that these aren’t quite up to delivering on everything Valve determined was important in VR.

The human brain is extremely good at using subtle cues to determine whether sounds are “real” or not, and all kinds of details come into play. For example, one’s ear shape, head shape, and facial geometry all add a specific tonal signature to incoming sounds that the brain expects to encounter. It not only helps to localize sounds, but the brain uses their presence (or absence) in deciding how “real” sounds are. Using ear buds to deliver sound directly into ear canals bypasses much of this, and the brain more readily treats such sounds as “not real” or even seeming to come from within one’s head, even if the sound itself — such as footsteps behind one’s back — is physically simulated with a high degree of accuracy. This and other issues were the focus of multiple prototypes and plenty of testing. Interestingly, good audio for VR is not all about being as natural as possible. For example, low frequencies do not occur very often in nature, but good bass is critical to delivering a sense of scale and impact, and plucking emotional strings.

“Hummingbird” prototype using BMR drivers. Over twenty were made and lent to colleagues to test at home. No one wanted to give them back.

The first prototype demonstrated the value of testing a concept as early as possible, and it wasn’t anything fancy. Two small speakers mounted on a skateboard helmet validated the idea of off-ear audio delivery. It wasn’t perfect: the speakers were too heavy, too big, too sensitive to variation in placement, and had poor bass response. But the results were positive enough to warrant more work.

In the end, what ended up in the Index headset is a system that leans heavily on Balanced Mode Radiator (BMR) speaker design. Cambridge Audio has a short and sweet description of how BMR works; it can be thought of as a hybrid between a traditional pistonic speaker drivers and flat-panel speakers, and the final design was able to deliver on all the truly important parts of delivering immersive VR audio in a room-scale environment.

As anyone familiar with engineering and design knows, everything is a tradeoff, and that fact is probably most apparent in cutting-edge technologies. For example, when Valve did a deep dive into field of view (FOV) in head-mounted displays, we saw just how complex balancing different features and tradeoffs could be.

Fail Of The Week: In CAD, Remember To Model The Environment

What’s wrong with the above picture? Failure can be an excellent teacher, and [J. Peterson] reminds us all of this when he says to remember to model the environment when designing things in CAD. He contrasts a failure with a success to demonstrate what that means.

The failure was a stand for a screwdriver set, shown above. He modeled up a simple stand to hold a screwdriver handle and the bits in a nice, tight formation. He didn’t model any of parts, he just took some measurements and designed the holder. Everything fit just fine, but it had a major ergonomic problem: you can barely reach the handle because it is fenced in by the surrounding bits! Had he modeled all of the parts during the design phase, and not just the part he was making, this problem would have been immediately obvious during the design phase.

The contrasting success is an adapter he designed to mount an artistic glass marble to a lit display stand. The stand itself as well as the glass marble were modeled in CAD, then the adapter designed afterwards to fit them. With all of the involved objects modeled, he could be certain of how everything fit together and it worked the first time.

Now, to most people with a 3D printer of their own, discovering a part isn’t quite right is not a big (nor even a particularly expensive) problem to have, but that’s not the point. Waste and rework should be avoided if possible. To help do that, it can be good to remember to model the whole environment, not just the thing being made. Add it on to the pile of great design advice we’ve seen for designing things like enclosures and interfaces.