On Espresso – Part I

February 19th, 2010 by Nick Evans

Ah, coffee. What a great friend it has been. It’s been there countless times to wish me a good morning, to keep me company on a long road trip, or to stay up with me late at night studying. It’s seen me at my best and my worst. All I do for coffee is spray it with scalding water and throw it away when I’ve had enough.  (Between you and me, I don’t know what it’s getting out of this relationship.) But, it’s always been there at my side when I need it most.

Lately some of us here at MindTribe have had a fascination with coffee, specifically with espresso.  We not only enjoy drinking it, but making it is always a fun little experiment too.  Like so much that we do here, making espresso is very much both an art and a science.

To make your typical pot of drip coffee requires nothing more than some hot water, ground beans, and a filter. Mix them together and you have coffee! That’s it—so easy a caveman could do it! I love a good cup of drip coffee, but I find it technically boring (though Bluebottle might disagree).

Espresso is not so simple. After all, espresso is only possible with “recent” advances in technology, and it is pretty new relative to coffee. To make it properly, you need water at just the right temperature. You need the water at a specific pressure. You need a precisely ground 14 grams of espresso beans. You need 30 lbs of even pressure applied to the grounds. And you need to extract 2 ounces after 25 seconds or you did it all wrong. Blah, blah, blah, blah. All this sounds like a lot of work to most people. To us it sounds like fun.

If there was an IEEE standard for espresso extraction, it would include the rules below. These are inputs to a process, ingredients to a recipe. A proper espresso machine should be capable of reaching these levels closely and should do so consistently.

Inputs:

  • Water at 200°F, or 93°C – This refers to the water that is being pushed through the coffee grounds
  • About 9 bar of water pressure – This refers to the pressure of the water right at the top of the espresso ground “puck” just before it touches any coffee
  • Correct coffee grind – The fineness of the grind must be adjusted until it is just right.  This combined with tamping pressure and coffee ground quantity will determine how fast the espresso comes out.
  • 14 grams of coffee grounds – This is the agreed-upon standard for two shots of espresso (Most machines do two shots at once. Use 7 grams for one shot machines.)
  • 30 lbs of tamping pressure – After adding 14 grams of ground coffee, a tamper should be used to apply 30 lbs of even pressure to the top of the grounds

Now, even if a machine is capable of meeting such specifications, it is up to the person making the espresso to make sure it actually does so. On home machines, it is rare to have any instruments with which to monitor water temperature or pressure. Most of the time, the only metrics you get are from the end result: the espresso itself. This makes it somewhat of a guessing game until your brain starts learning correlations between what you put in and what you get out. The following is what most people will use to gauge how well they did:

Outputs:

  • 1 ounce of espresso per shot for a 25-30 second extraction time
  • Pours out like warm honey
  • A top layer that is dark brown, not blonde, with a slight tint of red
  • And, it should taste, um, good

This shot that turned out pretty well. Notice the color and thickness of the crema.

If you would like to begin experimenting with espresso yourself but do not have a machine, here are some recommendations in different price ranges. However, be sure to save some money for a grinder (that is a topic for another post).

Under $200:
DeLonghi EC155 – $95 at Amazon

DeLonghi EC155

People say that for the price, there is nothing better out there.

$200 – $1000:
Rancilio Silvia – $594 at Whole Latte Love

Rancilio Silvia

Silvia is picky about some things (the grind has to be just right for example) but can make a fantastic shot if she gets what she wants. It can make a great hobbyist machine too since there are many people out there upgrading and modifying these machines.

$1000 – $3000:
Expobar Brewtus III-R with Rotary Pump – $1899 at Whole Latte Love

Expobar Brewtus III-R

Wowee, what an awesome machine. PID control loops, rotary pumps, and E61 brew groups, oh my! If you have money to burn, send one of these to yourself. If you have more money to burn, send one to us.

We use a Rancilio Silvia. This model line has been around for a while and has stood the test of time. It’s not perfect, but we love it just the same.

Our Rancilio Silvia among some other coffee buddies

Pros:
Nice big brass boiler. Brass has a lot of thermal mass, which helps to keep the temperature steady.
58mm commercial-grade portafilter.
Three-way solenoid valve.
Generally competent. It is capable of meeting the required inputs for brewing espresso correctly. Many of the cheaper machines simply can’t meet the espresso specs no matter what you do.
Built like a tank.

Cons:
Only one boiler, so after you pull a shot you have to wait for it to rise up to steaming temperature.
Temperature can fluctuate despite the big boiler.  This is because it is regulated by a thermostat.
It’s picky about the grind. If it’s not just right, you likely won’t get a good shot.
Small water reservoir and drip tray.

Finally, to really feel like you fit into the cool coffee club, try to use these terms more throughout your day:

  • Espresso – A drink made from the high-pressure oil extraction of coffee beans.  Increased pressures are used in order to make a higher concentration and to extract different flavors than what is possible using conventional drip coffee machines. Espresso can be served itself or be used to make other drinks such as lattes or cappuccinos.
  • Crema – A syrupy but foamy layer of emulsified coffee oils that tops a shot of espresso.
  • Barista – This is the person making espresso either at a coffee shop or you with your own machine. Means bartender in Italian.
  • Portafilter – The handle thing on espresso machines.
  • Basket – The perforated cup that snaps into the portafilter. This is what filters the coffee and keeps the grounds out of your drink.
  • Pull a shot – To make a shot of espresso. The word “pull” comes from the days when the machines had levers to build the pressure rather than electric pumps.
  • Tamper – A tool used to compact the grounds. The compact grounds provide the resistance needed to build the pressure to extract the oils from the coffee grounds.
  • Expresso - A word a barista uses before they make you a bad cup of coffee.

Espresso is something that can be causally enjoyed, something that can become a real hobby, and for some a true obsession.  For us at MindTribe, I’d say we’re somewhere in the middle.

Products We Love: Lotus Elise

December 11th, 2009 by Steve Myers

If you hang around the MindTribe lounge long enough, in addition to becoming current on the latest Internet memes, you’ll hear passionate sales pitches from one of us to another.

You’d swear a royalty check was involved, or that we’re selling one of the thousands of products in that picture.

In actuality, great products are an inspiration to us. We know they’re the result of a talented team successfully forging it’s way through a jungle of thick vegetation, quicksand, and wild beasts conspiring to steer the team toward the Land of Mediocrity.

I wouldn’t be the first engineer to claim that the team behind the Lotus Elise successfully navigated this jungle, coming out the other side nearly unscathed. If an engineering team ever wore out their Rocky Theme Song cassingle during the traverse, it must have been this one.

To appreciate what’s the big deal with this car, you have to understand its mission: to provide extremely high performance at a relatively low price point. To pull this off, there are a host of elegant engineering solutions and optimizations, as well as some admittedly small details that simply offer up a geek-out moment in the right company.

Elise_cars

The first (right) and second (left) generation Lotus Elise

Much of the engineering challenge of the Elise was to make the car weigh as little as possible. The lighter a car, the more adept it is when the road isn’t straight, and the better it responds to both the gas and brake pedals.

The backbone of the car, or chassis, is the starting point for the rest of a car. Lightness is important here as a lighter chassis means a smaller (lighter) engine can be used, which means smaller brakes and tires can be used, and so forth.

To achieve chassis lightness, Lotus engineers came up with a novel idea for a production car: glue it together. Yep, just glue. No, not the body panels or trim—the load-bearing structure for the entire car. Why glue? The more traditional process—welding—heats metal up and weakens it, thus requiring thicker metal to compensate. Gluing enables use of the thinnest—and therefore lightest—metal structures possible.

Elise_glue

A glimpse behind the front wheel reveals orange-colored glue holding the chassis together

Another exciting aspect of the car is the extensive use of aluminum extrusions: they’re fast and cheap compared to equivalent tooling to form, stamp, and assemble traditional sheets of steel. Think of squeezing a toothpaste tube where the toothpaste is aluminum and the opening of the tube is the shape of the desired part. Engineers can quickly and inexpensively create building blocks for a car, and easily change the basic dimensions to create other vehicles.

Elise_tub

Aluminum extrusions can be seen throughout the cockpit—note the chassis side rails and structural cross-member integrated with the dash

Elise_hinge

The same extrusion process can be used for chassis rails and door hinges

To further minimize weight, the body of the car is made of thin fiberglass. It also enables creation of tighter “bends” in the surface and more complex shapes than sheet metal, which both designers and engineers are a fan of.

Elise_door

Fiberglass body panels are lightweight and enable complex shapes

Aside from minimizing mass, there are some noteworthy aerodynamic mechanisms built into the car to maximize performance.

To aid stability at speed and reduce drag, one wants air to flow as smoothly as possible beneath the car (think of the bottom of a boat moving through water). The bottom of the Elise is nearly completely flat to aid in achieving this goal.

Elise_bottom

The Elise’s flat bottom

At the rear of the car, a diffuser panel manages airflow for a clean transition out from beneath the bottom of the car to minimize flow separation—a low-pressure eddy current of air following the car around, doing its best to slow it down whenever the car is in motion.

Elise_diffuser

The rear diffuser manages airflow as it exits the bottom of the car

If you were sitting in a desk chair, and you wanted a friend to start spinning you around as fast as possible, would you hold your arms outstretched or tightly next to your body? If you held them next to your body, you would reduce your polar moment of inertia, or resistance to turning. Now what about if you were holding an engine in said chair on a twisty road? You’d want it on your lap, as close as possible to the chair’s axis of rotation. The Elise is a mid-engined design, enabling some of the heaviest parts of the car—engine, transmission, and passengers—to huddle together near the middle of the car (the “tub” design of the chassis also allows passengers to sit extremely low to the ground, which also makes for better handling dynamics).

Elise_engine

Engine and passengers sit together near the middle of the car to decrease polar moment of inertia, or resistance to turning

As for the geek-out details on the Elise, it is one of the few modern cars available without power steering, enabling a sense of feeling the road with one’s fingertips. Everything in the car that looks like metal is metal, and all the vents on the car are functional. Air for the radiator flows in through the big center opening, and out beneath the windshield. There is an oil cooler behind each of the smaller front openings, and air for the engine intake and cooling flows through the side gills.

Elise_vents

All vents have a (functional) purpose

How does everything come together on the road?

No two cars are optimized for exactly the same circumstances, so comparing them is a bit apples and oranges. But for sake of discussion, let’s park the Elise next to a couple of other small, iconic sports cars—the Mazda MX-5 Miata and Porsche 911—to see how they compare.

The 911, Miata, and Elise are similar in size (911 wheelbase 92.5″, Miata 89.2″, Elise 90.5″, whereas a BMW 3-Series Coupe is 107.3″*). Yet the Miata weighs in nearly 500 pounds more than the 1,975 pound Elise (and doesn’t include an integrated rollbar, like the Elise), while the 911 is a full 1,100 pounds heavier than the Elise (though it does include two tiny back seats and is much more comfortable and practical than the Elise).

Why does the weight matter? Take a look at acceleration times for the Porsche and Elise, which are nearly identical around 4.8 seconds for a 0-60 mph run. The Elise manages a (revised) EPA rating of 20/25/22 mpg (city/highway/combined), while the Porsche is 16/24/19. The Miata, with the same engine size as the Elise of 1.8L, is closer in fuel consumption to the Elise as you would expect at 20/26/23, but is significantly slower to 60 mph at 7.7 seconds.

Cost-wise, the price (for the base 2005 model year) of the Miata ($22,098) is roughly half of the Elise ($39,985), while the Porsche ($69,300) is about one-and-three-quarters that of the Elise. Strictly performance-wise, the Elise is a deal compared to the 911, turning in similar performance numbers. That’s not to say the Elise is the best choice given the Porsche would be significantly more practical and comfortable as a daily driver, and the Miata provides incredible bang-for-the-buck. But on purely performance-per-dollar merit, the Elise is hard to beat, which was the intended destination when the Lotus team set out through the jungle.

* All vehicle data based on 2005 model year. Vehicle data sourced from Edmunds.com, autos.aol.com, and respective vehicle manufacturers.

Poking Around with Multi-Touch: Building MindTribe’s Multi-Touch Mobile Reference Platform

July 2nd, 2009 by Alan Laursen

The iPhone was the breakthrough product that introduced multi-touch—the ability to manipulate a touch screen interface with multiple fingers at once—to the average consumer. Along with the popularity of the iPhone came the realization that this new technology could make a user interface more flexible and more intuitive than previously possible. As such, MindTribe has seen a surge in companies looking to incorporate multi-touch interfaces into their products.

While the tools needed to implement a multi-touch interface are increasing in availability, they are still not established enough to be in the hands of every company’s engineers or contract manufacturers, and product technologies and offerings are rapidly evolving from week to week.

Some of our clients see the addition of multi-touch as an avenue to differentiating themselves, some see a means of creating new user experiences, while others seek insight in determining whether multi-touch is feasible for their product.

The rush for multi-touch is on. To help our clients quickly get an intuitive feel for the possibilities and limitations of multi-touch interfaces, we built a mobile reference platform to enable quick and easy experimentation. The product of this effort, a handheld demo unit, will serve as an anchor to future client discussions on the technology.

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Mechanical Prototyping Processes: What to Use and When

June 19th, 2009 by Troy Edwards

Here at MindTribe, our product design team works with clients who have varied schedules and budgets. To best serve their individual needs, we use a variety of prototyping methods to create mechanical models for review. Sometimes the parts are used for engineering purposes, and other times the parts are purely cosmetic for interdisciplinary design reviews. Understanding the pluses and minuses of each process allows us to minimize time and budget while achieving the design objectives. Below is a short summary of the processes we use most often for small quantities of mechanical parts.

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Five Materials Worth Watching—A Distraction

October 29th, 2008 by Lori Hobson

MindTribe has an orb in the office that we need to stop watching. The orb glows red when the NASDAQ drops, glows green when it rises, and pulses when the index’s movement exceeds 4%. Lately, its perpetually pulsing red light has been making me feel as if a hooker moved in to the next row of cubicles. Ironically, the orb can’t be reconfigured to monitor something more optimistic than tech stocks because—in a true sign of the times—the Web site that supports it is now defunct.


The Orb Glows Red When the Market Is Down – Lately, We’ve Needed a
Distraction from Its Bad News
(photo credit: MindTribe)

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The Secret Link to Marketing Breakthrough Products

July 22nd, 2008 by Lori Hobson

Silicon Valley’s Coolest Invention May Be Its Design Community

“Designed by Apple in California,” it reads. It’s July 11, and I am coddling a new iPhone.

It’s not designed in America. Not designed in the US. It’s Designed in California. What is it about the Bay Area and our product design community? It’s not just Apple. We have attracted a startlingly disproportionate number of the world’s best industrial design and product development (ID/PD) people to our little pocket of shoreline. Perhaps history will recognize this West Coast Design community as more influential than the mass media or academic institutions appear to notice. Sometimes we can’t get our clients to acknowledge our role at all, let alone put it on their product label. Still most of the successful companies here recognize that this community plays an instrumental role in bringing their technology innovations to market.


iPhone’s label highlights ”Designed by Apple in California”

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MindTribe’s Interactive Exhibit

June 5th, 2008 by Jerry Ryle

What Engineers Do If You Give Them a Dial Tone

Someday, MindTribe’s headquarters will be made of interactive masonry. Each brick will be molded from recycled consumer electronics and in-mold decorated with a high-resolution OLED display. Thousands of bricks will cooperate with distributed intelligence to celebrate your importance as you pass by. Depending upon your mood—as determined by your expression, posture, gait, and temperature—our building might inform you of your portfolio performance, challenge you to improve your mixed martial arts, or lift your spirits with kittens that frolic after your shoelaces. Someday. To tide ourselves over until that day, we’ve installed a 65″ plasma television in our front window and have written an interactive game you can play with your cell phone.

Playing Games at 119 University Ave.
MindTribe’s New Interactive Exhibition on University Avenue

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Early Evidence the Designers Accord Is Working

April 21st, 2008 by Lori Hobson

A Question of In Mold Decoration and Recyclability

Skeptics beware. Last week, MindTribe encountered direct evidence that the Designers Accord is actually having an impact. An engineer and I were meeting with a vendor. I won’t lie. Our primary focus was in exploring some issues that might help achieve the design intent of our client’s ID team, not any altruism for the environment. Late in the discussion I asked, “So how recyclable is this stuff?”

The fascinating part of the vendor’s answer was not that he didn’t know – he didn’t. The part that was stunning is what this veteran sales rep said. He shot me a glance and said, “That is only the second time that I have been asked that. The first time was yesterday.”

The rep was an in-mold decoration (IMD) supplier who is well known and well liked within our ID/PD community. The people with whom he had met the previous day were industrial designers in San Francisco that MindTribe knows (and loves).

IMD on our HP notebook
IMD used by HP to achieve a pattern on a notebook

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A Drool-Worthy Process for Rapid Prototyping of Metal Parts

March 13th, 2008 by Lori Hobson

Direct Metal Laser Sintering Meets Formula-1 – Next Up Product Prototypes?

At my house, it’s not enough to love great products and every detail of how they were made. That fact is obvious to anyone who’s seen my less-than-interested daughter hold her ears and run out of the room screaming at the first peep of conversations involving “machining” or “part line.” Product design infatuation was clearly part of our marriage vows, along with brewing strong coffee, making soufflé, and having and holding until the end. But those who know my situation best know that a keen love of motorsport was also part of the pre-nup. So when Formula 1 starts using a new method of rapid prototyping in metal, well, the pairing of the two topics—racing + product—seems almost cause for a celebration where I live, or at least a multi-hour discussion of the method’s potential over dinner with our equally obsessive friends.

Bed of Parts

Real Metal Parts from an Astonishing Prototyping Process
(photo courtesy of 3T RPD)

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Mini-USB is dead. Long live Micro-USB!

February 14th, 2008 by Jerry Ryle

While digging through one of our many boxes of miscellany, we recently stumbled across a perplexing cable that seems to connect 1975 to 2000. Perhaps the ferrite bolus actually houses a small flux capacitor that reduces conducted tachyon emissions.

Cable that connects 1975 to 2000

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