PHONESATS

July 12, 2014


I really don’t know how I missed this one.   This document deals with “phone sats”.  You can get a better feel for the technology by taking a look at NASA press release 13-107.  Let’s do that right now.

RELEASE: 13-107

NASA Successfully Launches Three Smartphone Satellites

WASHINGTON — Three smartphones destined to become low-cost satellites rode to space Sunday aboard the maiden flight of Orbital Science Corp.’s Antares rocket from NASA’s Wallops Island Flight Facility in Virginia.

The trio of “PhoneSats” is operating in orbit, and may prove to be the lowest-cost satellites ever flown in space. The goal of NASA’s PhoneSat mission is to determine whether a consumer-grade smartphone can be used as the main flight avionics of a capable, yet very inexpensive, satellite.

Transmissions from all three PhoneSats have been received at multiple ground stations on Earth, indicating they are operating normally. The PhoneSat team at the Ames Research Center in Moffett Field, Calif., will continue to monitor the satellites in the coming days. The satellites are expected to remain in orbit for as long as two weeks.

“It’s always great to see a space technology mission make it to orbit — the high frontier is the ultimate testing ground for new and innovative space technologies of the future,” said Michael Gazarik, NASA’s associate administrator for space technology in Washington.

“Smartphones offer a wealth of potential capabilities for flying small, low-cost, powerful satellites for atmospheric or Earth science, communications, or other space-born applications. They also may open space to a whole new generation of commercial, academic and citizen-space users.”

Satellites consisting mainly of the smartphones will send information about their health via radio back to Earth in an effort to demonstrate they can work as satellites in space. The spacecraft also will attempt to take pictures of Earth using their cameras. Amateur radio operators around the world can participate in the mission by monitoring transmissions and retrieving image data from the three satellites. Large images will be transmitted in small chunks and will be reconstructed through a distributed ground station network. The JPEGS shown below will give indication as to the orbit.

phone-sats (1)

 

FLIGHT PATH

The systems are now operating properly and orbiting Earth delivering information that will be used in evaluating the program.  I feel NASA has married the private and public sectors to produce workable technology that will represent much lower costs yet, hopefully, the same results. Time will tell. According to Chad Frost, Chief of the Mission Design Division at NASA Ames, “We all carry around smartphones these days, so we’re intimately familiar with what a smartphone is and what it can do.  And a few years ago, we had the intriguing idea that you might actually be able to build a spacecraft around a smartphone. So, we were very intrigued by the notion that you could build a very small spacecraft based entirely on consumer electronics devices and other low-cost systems.”

THE CONFIGURATION:

JPEGs of the configuration may be seen by the following JPEG:

phonesat_2_5--NASA

PhoneSat is a nano-satellite, categorizing the mass as between one and ten kilograms. Additionally, PhoneSat is a 1U CubeSat, having a volume of around one liter. The PhoneSat Project strives to decrease the cost of satellites while not sacrificing performance. In an effort to achieve this goal, the project is based around Commercial Off-The-Shelf (COTS) electronics to provide functionality for as many parts as possible while still creating a reliable satellite. Two copies of PhoneSat 1.0 were launched mid April 2013 along with an early prototype of PhoneSat 2.0 referred to as PhoneSat 2.0.beta.  PhoneSat 2.4 is sitting on the launch pad ready for lift-off.  The PhoneSats use a Google Nexus smartphone running the Android 2.3.3. operating system.  Two of the PhoneSats have standard smartphone cameras that were used to take images of Earth from space.   The first JPEG in this post shows one of those pictures.

Now, here is a fact that blows me away.  NASA engineers kept the total cost of the components for the three prototype satellites in the PhoneSat project between $3,500 and $7,000 by using primarily commercial hardware and keeping the design and mission objectives to a minimum.
NASA added items a satellite needs that the smartphones do not have — a larger, external lithium-ion battery bank and a more powerful radio for messages it sends from space. The smartphone’s ability to send and receive calls and text messages has been disabled.  Each smartphone is housed in a standard cubesat structure, measuring about 4 inches square. The smartphone acts as the satellite’s onboard computer. Its sensors are used for attitude determination and its camera for Earth observation.

TESTING:

There are several phases to “powering-up” the PhoneSat system.  These are as follows:

Phase 1: After the initialization phase, the phone is in phase 1 in which it performs a health check. During this phase, each sensor and subsystem is checked and data is compiled into a standard health packet, stored in the smartphone’s SD card and transmitted over the beacon radio at a regular interval of 30 seconds. The last 10 health packets are stored in the SD card. After every 10 packets sent, the beacon radio is rebooted. This phase happens during the first 24 hours of the mission. The mission time is kept in the phone throughout the mission so that a system reboot during this phase does not reset the 24 hour countdown A health packet consists of: Satellite ID, restart counter, reboot counter, Phase 1 count, Phase 2 count, time, battery voltage, temp 1, temp 2, accel X, accel Y, accel Z, Mag X, Mag Y, Mag Z, text “hello from the avcs”.

Phase 2: This phase starts once a full system health check has been performed. During this phase, image packets and health packets are sent to Earth through the beacon radio. A health packet is sent once for every 9 image packets downlinked.

This phase can be divided in 3 sub-phases:

• Health Data Measurements: Health data is measured and the 10 most recent samples are stored in the SD card.

• Health Data Downlink: Once 9 packets have been sent through the beacon containing image information, the 10th one is reserved for a health packet.

• Image Sequence: One picture is taken every minute until 100 pictures are taken and stored to the SD card. Pictures are then analyzed and the top image is selected. This image is packetized and compiled into standard image packets. These image packets are transmitted over the beacon radio coupled with health packets in the ratio explained above.

Safe Mode: If the watchdog detects that the phone is not sending any data to the radio for a certain period of time, the spacecraft functionality is reduced to the bare minimum. In this condition, the spacecraft only transmits health data containing the last 10 sensor data values stored in the SD card prior to failure. This mode lasts for 90 minutes. After this period, the spacecraft resumes its normal operations. A safe mode packet consists of: Satellite_ID, last 10 voltage values, last 10 temperature sensor 1 values, last 10 temperature sensor 2 values, text “SAFEMODE”.

TIMELINE:

The timeline for research and development started in 2009. Definite planning has gone into the program.  You may see that timeline below.

TIME LINE

As mentioned above, PhoneSat 2.0 has already been scheduled for launch later on this year, 2014.  The technology is definitely evolving. NASA is working towards extremely low-cost deployments that provide workable communications to government agencies and private concerns.

I welcome your comments.

STRESS

July 9, 2014


It’s amazing how some things you hear stay with you over the years.  My grandfather, W.L., died about forty (40) years ago but I still remember him saying there are three problems that will significant and deleterious stress:  1.) Problems at home, 2.) Problems with health, and 3.) Financial problems. His comments were based upon experience for the most part. He and his wife Elizabeth raised four children during the Great Depression so scraping by was the norm and not the exception.  There were many times, according to him, their food came by virtue of fishing and hunting.  They would barter and bargain with neighbors for many things needed on a daily basis.  As it turns out, his opinion has been confirmed by a study entitled: “The Burden of Stress in America” published by NPR/ Robert Johnson Foundation/Harvard School of Public Health.  This study called “The Burden of Stress in America Survey “was conducted from March 5 to April 8, 2014 with 2,505 respondents. The survey examines the role stress plays in different aspects of Americans’ lives, including the public’s personal experiences of stress in the past month and year, the perceived effects of their stress and causes of that stress, their methods of stress management and their general attitudes about effects of stress in people’s lives.   The methodology is as follows:   From March 3 through April 8, 2014, a nationally representative sample of 2,505 adults age 18 and older were interviewed.  The interviews were conducted in English and Spanish. The margin of error for total respondents is +/- 2.4 percentage points at the 95% confidence level. Of the total sample, 633 said they have experienced a great deal of stress in the past month. The margin of error for this group is +/- 4.6 percentage points at the 95% confidence level.  The results are not surprising but certainly telling. The charts given by this post come from that study.  The text and explanation of the charts is mine.

THE RESULTS:

I can certainly understand why the number one stress in a person’s life is the absence of health, even if those health problems are temporary.  I have been there, done that, got the “T” shirt.  You never forget your time in intensive care.  It’s a game-changer.   As you can see from the bar chart below, problems with health are approximately twice the next most mentioned item on the list.  I have recently experienced the loss of my mother due to Alzheimer’s and even though you know what’s coming, it is a tough pill to swallow.  It is also very interesting to me that finances are NOT on this list even though financial matters can and will exacerbate issues with health and other areas of stress.

MOST STRESSFUL YEAR

In looking at the chart below, the first three (3) items are definitely health related.  It is also apparent those individuals or individual households in the under $20,000 income group have significant reasons for stress related problems.  There also can be made a case for low income fostering poor health conditions.

Groups Experiencing High Stress Levels Last Month

I was somewhat surprised that being the parent of a teen would engender such stress and that stress made the list.  My wife and I have three boys and five grandchildren.  I can relate although we felt this was just a part of parenting.  We did not have issues with alcohol, drugs, sex, etc etc.  Single moms and dads deserve great respect due to the burden they carry in raising a teenager.  It’s “yeoman” work.   Now I know we were lucky.

There are certainly experiences on a daily basis that lend themselves to over-the-top stress.  Several may be seen as follows:

MOST COMMON STRESS RISERS

The top three on this list come as no real surprise.  With cutbacks at work more and more individuals are asked to take on additional responsibilities which mean more time at work and less time with the family.  Fewer vacations.  The “average” full-time employee works 1,700 hours per year and it is estimated that many employees refuse to take all of the vacation time coming to them due to work load and related work environment.   The big surprise is the last on the list. Twenty-eight percent say they are unhappy with their looks.   I would love to know how many people within that 28% are overweight.  (Just a thought.)

10 DAILY EVENTS

It’s very obvious from the chart above that people are very disturbed with political “types” and watching, reading or listening to the news is a great contributor to the stress we experience.    You have heard the phrase, “If it bleeds—it leads”.  Maybe we should have one day devoted to nothing but good news or even better, maybe we should have a “no-TV” night at least once during every week. How about this—let’s FIX our national problems by voting them all out and starting over.  How about that?

The chart below would indicate we sometimes do not have control over the problems, consequently the stress we experience.  Dealing with aging parents and their health, as well as our own, can apply great stress to an everyday life.

EFFECTS OF STRESS

All of this is well and good but how do we deal with stress?  How do we cope?   What are the responses to the stress we feel?  The next two charts will show these responses.

TOP 10 RESPONSES TO STRESS

EFFECTIVENESS OF ACTIONS

We all would love to avoid as much stress as possible under most circumstances.  In our day, unemployment, health, finances, inter-personal relationships and work life all must be dealt with daily. What we can control—we must control.  In my life, simple organization on a daily basis, then a monthly basis helps tremendously. The following very items are things I have found to be great aids to removing as much stress as possible.

  • Keep a daily and monthly planner.  In that planner, put notifications dealing with bills due with specific due dates.
  • Keep a daily telephone log.  Phone calls received and made.  This greatly helps memory and can save the day relative to dates and times when calls are made. I don’t necessarily mean personal calls to family.  All business calls—absolutely.
  • DE-CLUTTER.  Keep a clean desk.
  • FILE or have someone file for you. Get organized. Know where things are.
  • (OK, this one may seem trivial but here it is.)  Have all work materials; i.e. scissors, tape, copy paper, pencils, erasers, staples, file folders, etc. needed on a daily basis in your office. Do not do the “step and fetch-it” day after day.
  • Have a specific time to answer e-mail and return phone calls.  Don’t jump every time you receive an e-mail thinking you have to answer it right away.
  • Refuse to attend meeting you do not feel will produce results relating to your goals, company and personal.  (This is a tough one but get in the habit.)
  • As best you can, save the weekends for yourself.  If you have to work 80 hours a week, put those hour in between Monday and Friday. Most of us have families and they deserve your time as much as your supervisor.  (If you are the boss, realize the boss needs time off for good behavior.)
  • Exercise in a vigorous fashion at least three times per week.
  • Watch what you eat and the portions. DON’T DO FAST FOOD. Eat properly.
  • SLEEP at least eight (8) hours per night.
  • READ. Give up television one or two nights per week and possibly on the weekends.
  • The Internet is a “black hole”. Do NOT waste time on Face Book, Twitter, etc etc.  Your time is valuable.
  • IF YOU LIKE THEM CALL THEM. Forget e-mail to loved ones, friends and family.  Listen to their voice. (NOTE: If you don’t like them forget it.)
  • Remove yourself from toxic people. People who have nothing good to say about anything.

These are just a very few recommendations but I do feel moving towards a condition in which we negotiate the controllable is a great place to be.

I welcome your comments.


Several years ago I traveled with three (3) other guys to participate in the 50th annual Rattlesnake Roundup.  We considered ourselves to be of sound mind although the subject remains for debate.  The annual event is held in Sweetwater, Texas, which is just west of Abilene or about 1,012.12 miles from our east Tennessee location.  Each person drove four (4) hours non-stop, one-way for this adventure.  It took approximately sixteen (16) hours. (Then again, who’s counting?)  I don’t know if you have ever been to Sweetwater but it’s as flat as a table, hot as hell (even in March), dusty as the Sahara and the wind ALWAYS blows.  Even with this being the case, the residents were absolutely convinced the city was the Garden of Eden. “No place I would rather be”, was a frequent comment, even with rattlesnakes in the front yard.  I suppose we all feel that way about our home town.  I certainly do. Well, there are other towns that might not warrant that high praise.  Places more toxic and considerably less desirable.

Forbes Magazine recently published an article called “The Most Miserable Cities in the United States”. They based their examination on the following criteria for the 2013 calendar year:

  • Level of violent crime
  • Unemployment rate
  • Home foreclosures
  • Net migration from city
  • Traffic congestion
  • Local and state taxes
  • Commute times
  • Weather

A fairly complete and meaningful list of specifications for the ranking.

With this being the case, I have listed in reverse order what residents indicate to be the most miserable cities in the United States.  Here we go:

20.) Youngstown, Ohio

19.) Gary, Indiana

18.) Poughkeepsie, New York

17.) Cleveland, Ohio

16.) Atlanta, Georgia

15.) Atlantic City, New Jersey

14.) Milwaukee, Wisconsin

13.) Camden, New Jersey

12.) St. Louis, Missouri

11.) Toledo, Ohio

10.) New York, New York

9.) Lake County, Illinois

8.) Stockton, California

7.) Warren, Michigan

6.) Vallejo, California

5.) Modesto, California

4.) Chicago, Illinois

3.) Rockford, Illinois

2.) Flint, Michigan

1.) Detroit, Michigan

In doing the count, we conclude the following:

  • Three from Ohio
  • Three from Michigan
  • Three from Illinois
  • Three from California
  • Two from New Jersey
  • Two from New York

This list was compiled with no political input considered, just the factors given above.  No Democrat vs. Republican—just the eight (8) items mentioned.  I have been to over half the cities on this list and found them to be nice places to visit.  I honestly feel that when (and if) our economy ever returns to livable conditions and employment improves, turn-a-round will be definitely possible.    Crime remains a HUGE issue with the inner-city.  Gang and drug violence will be forever with us I fear.  I’m not too sure how we deal with that.

FDR was correct when he said, “We have nothing to fear but fear itself”.  Our politicians need to step up, make something happen, forget their “base”, forget their legacy, forget reelection, throw together for the betterment of the populace, and lose the special interest groups.      They can and possibly should be replaced!   I welcome your comments.

ALIBABA

July 3, 2014


One of the services my company (Cielo Technologies, LLC) provides is locating resources for clients, both individual and commercial.  We find people and vendors that can do “stuff”.  People and companies that can perform successfully, on time, following specification given as a part of a contractual arrangement.  In short, we provide sourcing services for commercial concerns.  Ones that can get the job done.

In 2006, I was given a call by a manufacturing company providing extension springs for doors used on residential cooking products.  This company has been in business since 1974 with springs being the first product produced.  Due to decreasing demand for the product and increasing costs for hard-drawn and oil-tempered wire, they made a management decision to out-source manufacturing efforts.   I immediately started searching for vendors, both domestic and foreign.  I looked at thirty-seven (37) companies that I eventually interviewed for the products required.  During that search, the name ALIBABA, came up frequently—very frequently.  Let’s take a look at this company.

HISTORY:

Alibaba Group was established in 1999 by 18 people led by Jack Ma, a former English teacher from Hangzhou, China.  Jack Ma chose the name because it is well-known around the world and can be easily pronounced in many languages.  According to Mr. Ma,  “One day I was in San Francisco in a coffee shop, and I was thinking Alibaba is a good name. And then a waitress came, and I said do you know about Alibaba?  And she said yes. I said what do you know about Alibaba, and she said ‘Alibaba and 40 thieves’. And I said yes, this is the name!  Then I went onto the street and found 30 people and asked them, ‘Do you know Alibaba?’ People from India, people from Germany, people from Tokyo and China… They all knew about Alibaba.  Alibaba — open sesame.  Alibaba is a kind, smart business person, and he helped the village. So…easy to spell, and globally known. Alibaba opens sesame for small- to medium-sized companies. We also registered the name Alimama, in case someone wants to marry us!”.  E-commerce is global so the company needed a name that was globally recognized.  Alibaba brings to mind “open sesame,” representing the hope that their platforms would open a doorway to improved sales and even fortune for small businesses.  From the outset, the company’s founders shared a belief that the Internet would level the playing field by enabling small enterprises to leverage innovation and technology to grow and compete more effectively in the domestic and global economies.  Since launching its first website helping small Chinese exporters, manufacturers and entrepreneurs to sell internationally, Alibaba Group has grown into a global leader in online and mobile commerce. Today the company and its related companies operate leading wholesale and retail online marketplaces as well as Internet-based businesses offering advertising and marketing services, electronic payment, cloud-based computing and network services and mobile solutions, among others.

PRESENT DAY:

As of March 31, 2014, Alibaba employed more than 22,000 people around the world.  Quite a jump from the original eighteen.   As of December 31, 2013, the company maintained seventy-three (73) offices in mainland China and sixteen (16) offices outside mainland China.  In 2012,two of Alibaba’s portals together handled 1.1 trillion yuan ($170 billion) in sales, more than competitors  and e-Bay and Amazon.com combined.  In  March 2013 it was estimated by The Economist magazine to have a valuation between $55 billion to more than $120 billion.  The following timeline will indicate the growth of the company.

  • In May 2003, Taobao was founded as a consumer e-commerce platform.
  • In December 2004, Alipay, which started as a service on the Taobao platform, became a separate business.
  • In October 2005, Alibaba Group took over the operation of China Yahoo! as part of its strategic partnership with Yahoo! Inc.
  • In November, 2007, Alibaba.com successfully listed on the Hong Kong Stock Exchange.
  • In April 2008, Taobao established Taobao Mall (Tmall.com), a retail website, to complement its C2C marketplace.
  • In September 2008, Alibaba Group R&D Institute was established.
  • In September 2009, Alibaba Group established Alibaba Cloud Computing in conjunction with its 10-year anniversary.
  • In May 2010, Alibaba Group announced a plan to earmark 0.3% of its annual revenues to fund environmental protection initiatives.
  • In October 2010, Taobao beta-launched eTao as a shopping search engine.
  • In June 2011, Alibaba Group reorganized Taobao into three separate companies: Taobao Marketplace, Taobao Mall (Tmall.com) and eTao.
  • In July 2011, Alibaba Cloud Computing launched its first self-developed mobile operating system, Aliyun OS over K-Touch Cloud Smartphone.
  • In January 2012, Tmall.com changed its Chinese name as part of a rebranding exercise.
  • In March 2014, Alibaba group said it will begin the process of filing for an initial public offering in the U.S.
  • Prior to its IPO filing on Form F-1 as a foreign issuer in the U.S., Alibaba undertook an aggressive acquisition spree – previously atypical for the company – acquiring numerous majority and minority stakes in companies including micro-blogging service Weibo, China Vision Holdings, and car sharing service Lyft.
  • On May 6, 2014 Alibaba Group filed registration documents to go public in the U.S. in what may be one of the biggest initial public offerings in American history.
  • On June 5, 2014 Alibaba group agreed to take a 50 percent stake in Guangzhou Evergrande Football Club, winners of 2013 Asian Champions League, for 1.2 billion yuan ($192 million).
  • In June 2014, Alibaba acquired the Chinese mobile internet firm UCWeb. The price of the purchase has not been disclosed, but the company did claim that the acquisition creates the biggest merger in the history of China’s internet sector.

MARKETS AND SALES:

Mr. Ma was definitely on to something as the chart below will indicate.  The projection through 2017 is dramatic.

CHINAS E-COMMERCE MARKET

China’s online shopping market is absolutely dominated by Alibaba.

CHINA'S ON-LINE SHOPPING MARKET

If we look at other companies related to the Internet, we see the following, in billions:

HOW ALIBABA COMPARES WITH OTHER E-COMMERCE SITES

The gross merchandise volume in 2013 looked as follows:

GROSS VOLUME IN MERCHANDISE

As you can see, the company is a “player” on the global stage.

In the very near future, Alibaba will issue an IPO.  At this time, the Wall Street Journal estimates the IPO could be one of the largest in corporate history.  Only time will tell.

By the way, I placed the spring business with a company in Texas.  We wanted to keep the product “at home” for several reasons, 1.) Communication, 2.) Transportation, 3.) Import complexities, 4.) Changing exchange rates and 5.) Buy American.  With this being the case, Alibaba is still a great source for products purchased.  I would invite you to take a look.

I always welcome your comments.

ENCODERS

June 30, 2014


OK, what is an encoder?  Who cares?  What do they do?  Why should I know about them?  How are they used?   Let’s first start by defining the process of encoding in general.  According to the Merriam-Webster dictionary the definition of encoding is:

“to convert (as a body of information) from one system of communication into another; especially:  to convert (a message) into code”. 

Now that we have the definition, are there devices mechanical or otherwise, allowing for encoding of information from one system of communication to another system of communication?   A resounding YES!   For our purposes, an encoder is an electromechanical device that converts information from one format or code to another, for the purposes of standardization, speed, secrecy, security or compressions.  Encoders are sensors for monitoring position, angle and speed of moving mechanisms.   There are applications requiring very precise placement of components relative to a datum or mating surface.  Essentially, encoders can be categorized as rotary or linear.  Rotary encoders are sub-divided into incremental and absolute encoders.   There are many processes that require exact positioning of mechanisms, either linear or rotary.  In some applications, such as remote surgery using robotic systems, position and angle are absolutely critical.  Encoders provide this information to software and controllers.

LINEAR ENCODERS:

Linear encoders are sub-divided into wire draw and non-contact types.    A linear encoder is for frictionless length measurement and determining position and is a sensor, transducer or reading-head linked to a scale that specifies position of a part relative to a datum point.  The sensor reads the scale and converts position into an analog or digital signal that is transformed into a digital readout. Movement is determined from changes in position with time. Both optical and magnetic linear encoder types function using this type of method. However, it is their physical properties which make them different.

The JPEGs below will indicate the “hardware” typically used relative to linear encoders.

LINEAR ENCODER SPECIFICS

LINEAR (2)

ROTARY ENCODER:

 A rotary encoder also called a shaft encoder or magnetic encoder, converts angular position or motion of a shaft or axle to an analog or digital code.   A rotary encoder consists of two parts: a rotor and a sensor. The rotor turns with the shaft and contains alternating evenly spaced north and south poles around its circumference. The sensor detects these small shifts in the position N>>S and S>>N. There many methods of detecting magnetic field changes, but the two primary types used in encoders are: Hall Effect and Magneto resistive.  Hall Effect sensors work by detecting a change in voltage by magnetic deflection of electrons. Magneto resistive sensors detect a change in resistance caused by a magnetic field.

Two rotary encoder configurations may be seen as follows:

ROTARY (1)

This type of encoder would require a shaft coupling to operate.

ROTARY (2)

 

For this encoder, the shaft would be fitted into the opening shown and secured with key-seat or other fastening mechanism.

In each case, electrical connections are necessary to send encoded data to a software package then to a controller mechanism.

TYPICAL USES FOR ENCODERS:

The mechanical world would be a very different place if it were not for linear and rotary encoders.  Let’s take a look at real-life uses for both.

  • Automotive GPS and radios
  • Medical equipment
  • Audio/visual recording/mixing equipment
  • Avionics
  • Transportation equipment
  • Fitness equipment
  • Test and measurement equipment
  • Agricultural equipment
  • Construction equipment
  • Oscilloscopes
  • Pulse/signal generators

As with any technology, there are advantages and disadvantages as follows:

 ADVANTAGES:

Highly reliable and accurate
Low-cost feedback
High resolution
Integrated electronics
Fuses optical and digital technology
Can be incorporated into existing applications
Compact size

DISADVANTAGES:

Subject to magnetic or radio interference (Magnetic Encoders)
Direct light source interference (Optical Encoders)
Susceptible to dirt, oil and dust contaminates –

I might note the disadvantages can be compensated for by applying appropriate shielding and components to the overall assembly.

SUMMARY:

Sophisticated robotic systems use encoders in many places to ensure accuracy when the need to accurately position mechanisms is paramount. Users of equipment are usually oblivious to their presence.  They work silently to perform predetermine tasks as dictated by software.

 

LIGHT-CURE ADHESIVES

June 24, 2014


The following post is taken from a training module written by this author and published through PDHonline.org.   PDHonline is a web site offering continuing education units (CEUs) for professional engineers. 

INTRODUCTION:

At the present time, adhesive manufacturers offer products classified as Cyanoacrylates, Epoxies, Hot Melts, Silicones, Urethanes, Acrylics (one-part and two-part) and Light-cures.  These classifications provide products with specific characteristics that allow for bonding, gasketing, potting and encapsulating, retaining, thread-locking and thread-sealing.  This post provides information on one very specific and very special adhesive category— LIGHT-CURE.

Light-cure adhesive technology offers a new approach to bonding similar or dissimilar substrates by using either ultraviolet light (UV) or light within the visible spectrum.  Extremely rapid cure times, superior depth of cure, (up to four inches) and easy dispensability are only three of the benefits when using these adhesives combined with the appropriate processes.   The newer visible light-cure materials can offer adhesion comparable to most commercially available UV adhesives, with particularly high adhesion on polycarbonate and polyvinylchloride (PVC) materials.  All equate to lower cost of assembly, more freedom when designing components and products and the saving of valuable production time.  This method of adhesion is extremely valuable when bonding thin films, needing heightened safety relative to skin and eyes and when bonding heat sensitive materials.  This process can lessen, or eliminate, the need for costly and harmful chemicals from the workplace and can be solvent-free and non-hazardous.  The use of light-cure adhesives will result in a very clean and “friendly” worker environment with no significant material disposal costs.  There is no need to mix, prime or rush to apply the adhesive due to minimal time to dispense.

HISTORY:

Approximately forty (40) years ago, the adhesive industry introduced an acrylic-based adhesive that cured or solidified upon exposure to ultraviolet light.  This was a tremendous breakthrough for the manufacturers and within a short period of time these adhesives became commercially available.  This offered distinct advantages over traditional adhesives categories such as cyanoacrylates (CAs) and epoxies.  Rapid cure times, adhesion to a variety of substrates and the ability to fill large gaps; i.e. 0.030 to 0.050 inches, were real winners with designers and assembly “shops”.  It allowed for greater flexibility in design and assembly.   Recent developments have produced adhesives that will cure using light within the visible spectrum.  This offers great possibilities over adhesives previously requiring UV cure.  These adhesives, UV/V (Ultraviolet/ Visible) were introduced in the 1990’s and involve employment of existing broadband-emitting UV light sources able to utilize an enlarged portion of the light spectrum.  The mechanism by which this happens is the introduction of photo initiators that react exclusively with light in the visible wavelengths; i.e. those which exceed 425 nm.  Development, as you might suspect, is still occurring and each year materials with improved mechanical characteristics and ease in application are being introduced into the commercial marketplace.

 

TYPICAL APPLICATIONS:

When we discuss applications, we find they generally fall into one of several basic categories; i.e. 1.) Bonding,  2.) Sealing,  3.) Cured-In-Place Gaskets,  4.) Potting and  5.) Coating.  With this in mind, we can see the following product applications now using the light-cure technology:

1.)Musical instruments

2.) Toys

3.) Sporting equipment

4.) Jewelry

5.) Optics (eye glasses )

6.) Needles

7.) Syringes

8.) Lighting

9.) Electronic Asms.

10.) Appliance assembly (refrigeration, laundry, etc.)

11.) Strain relief for wires and cord sets

12.) Conformal coating for PC boards

13.) Parts tacking

14.) Coil terminating

15.) Tamper-proofing

The development of light-curing adhesives has been enhanced by the latest generation of curing equipment.  This equipment includes both flood and point source configurations using bulb or lamp based systems.  In addition, equipment utilizing LED technology is now available for use with these adhesives.  The benefit here is that LEDs generate focused wavelengths that create appreciably tighter output range relative to regular visible lamp technologies.   Furthermore, because superfluous light and heat are not emitted, LED technology has proven to be both highly efficient and highly cost effective.  As might be expected, as a result of their small size, LED curing systems provide an LED light source that is perfect for curing tiny component parts.   The photographs and graphics below will give you an idea as to what types of products are now being produced using light-cure technology.

Figure 1

FRACTIONAL HP MOTOR ASSEMBLIES

Figure 2

 

OUTDOOR WINDOW ASSEMBLIES

Figure 3

OUTDOOR LIGHTING ASSEMBLIES

ADVANTAGES AND DISADVANTAGES:

Let us list now the relative advantages and disadvantages of using UV and V light-curing adhesives.

ADVANTAGES:

1.)     Reduced labor costs

2.)    Simplified automation when automation is used

3.)    Easier alignment of parts before cure

4.)    Improved in-line inspection

5.)    Reduced work in-process

6.)    Shorter cycle times due to rapid curing of components

7.)    Shorter lead times to customer possibly leading to reduced inventories

8.)    Fewer assembly stations required due to rapid cure times

9.)    No racking during cure

10.)No mixing generally required

11.)No pot life issues meaning generally much less waste of materials

12.)Reduced dispensing costs

13.)No hazardous waste due to purging or poor mixing

14.)No static mixers

15.)Easier to operate and maintain dispensing systems

16.)Better work acceptance

17.)No explosion proof equipment required

18.)Reduced health issues

19.)Reduced regulatory costs; i.e. reduced restrictions on volatile organic compounds

20.)Reduced disposal costs

21.) Very fast cure times

22.) Ideal for heat sensitive films and thin components

23.)Lower energy consumption required during processing of adhesive systems

24.)Visible light-cure adhesives cure through colored or tinted substrates

25.)Allows for miniaturization of component parts needing bonding or potting

26.)Improved manufacturing yield, quality and reliability

27.)Low odor

28.)RoHS compliant

29.)UL recognized materials available

30.)Low entrainment of moisture due to rapid cure times

31.)Solvent free

32.)Reduced material and process costs

DISADVANTAGES:

As with any process or adhesive material, there are several disadvantages. These are as follows:

1.)    Expenditure for curing equipment is necessary

2.)    Shielding when UV light is used may be necessary

3.)    UV blocking eye protection may be necessary depending upon the processing equipment

4.)    A radiometer may be necessary to measure the intensity of the UV light

5.)    When using UV light, the light source MUST reach the bond line if complete cure is to be had.  This means that transmission of light through at least one substrate is crucial.  Some substrates have UV inhibitors to lessen or eliminate degradation of the component.  These inhibitors will inhibit the penetration and lessen adhesion necessitating another method of bonding.  ( This is by far the biggest disadvantage for UV curing. )  A graphic depiction is given below that illustrates the principal.

As you can see, there are very specific uses for light-cure adhesives and engineers and engineering managers would be well-served to explore the possibilities.  I welcome your comments.

 

 

RoHS

June 18, 2014


Several days ago I published a blog concerning “Conflict Minerals”.  This is a very real attempt issued by legislatures to lessen or eliminate minerals and substances mined to support destructive political actions taken to subjugate populations.  Necessary actions must be taken by engineers and management to evaluate products received insuring none contain conflict minerals.  Companion legislation has been issues by the European Community (EU )to insure environmental issues are also addressed.  RoHS is the abbreviated name for this directive. Any company doing business in the European Community must adhere to RoHS requirements.  This is mandated policy affecting all manufacturers supplying domestic consumer products or commercial products.  The purpose of RoHS  is to require companies to quantify six (6) materials used in the manufacturer and assembly of products.  Let’s take a look. The European Union set forth RoHS (Restriction of Hazardous Substances) Directive to establish environmental guidelines and legislation to reduce the presence of six (6) materials deemed hazardous to the environment.  To comply, products entering the EU must not have a homogeneous presence of these materials above the following levels by weight percentage:

  • Lead (Pb) < 0.1%
  • Mercury (Hg) < 0.1%
  • Cadmium (Cd) < 0.01%
  • Hexavalent Chromium (CrVI) < 0.1%
  • Polybrominated Biphenyls (PBB) < 0.1%
  • Polybrominated Diphenyl Esters (PBDE) < 0.1%

RoHS Compliance is determined by a combination of supplier certification and engineering design verification.    The directive applies to equipment as defined by a section of the WEEE directive.  The Waste Electrical and Electronic Equipment Directive (WEEE Directive) is the European Community directive 2002/96/EC on waste electrical and electronic equipment(WEEE) which, together with the RoHS Directive 2002/95/EC, became European Law in February 2003. The WEEE Directive set collection, recycling and recovery targets for all types of electrical goods, with a minimum rate of 4 kilograms per head of population per annum recovered for recycling by 2009. The RoHS Directive set restrictions upon European manufacturers as to the material content of new electronic equipment placed on the market. The symbol adopted by the European Council to represent waste electrical and electronic equipment comprised a crossed out wheelie bin with or without a single black line underneath the symbol. The black line indicates that goods have been placed on the market after 2005, when the Directive came into force. Goods without the black line were manufactured between 2002 and 2005. In such instances, these are treated as “historic weee” and falls outside re-imbursement via producer compliance schemes. The following numeric categories apply:

  1. Large household appliances.
  2. Small household appliances.
  3. IT & Telecommunications equipment (although infrastructure equipment is exempt in some countries)
  4. Consumer equipment.
  5. Lighting equipment—including light bulbs.
  6. Electronic and electrical tools.
  7. Toys, leisure, and sports equipment.
  8. Medical devices (exemption removed in July 2011)
  9. Monitoring and control instruments (exemption removed in July 2011)
  10. Automatic dispensers.
  11. Semiconductor device

Batteries are not included within the scope of RoHS. However, in Europe, batteries are under the European Commission’s 1991 Battery Directive (91/157/EEC), which was recently increased in scope and approved in the form of the new battery directive, version 2003/0282 COD, which will be official when submitted to and published in the EU’s Official Journal. While the first Battery Directive addressed possible trade barrier issues brought about by disparate European member states’ implementation, the new directive more explicitly highlights improving and protecting the environment from the negative effects of the waste contained in batteries. It also contains a program for more ambitious recycling of industrial, automotive, and consumer batteries, gradually increasing the rate of manufacturer-provided collection sites to 45% by 2016. It also sets limits of 5 ppm mercury and 20 ppm cadmium to batteries except those used in medical, emergency, or portable power-tool devices. Though not setting quantitative limits on quantities of lead, lead-acid, nickel, and nickel-cadmium in batteries, it cites a need to restrict these substances and provide for recycling up to 75% of batteries with these substances. There are also provisions for marking the batteries with symbols in regard to metal content and recycling collection information. It also does not apply to fixed industrial plant and tools.  Compliance is the responsibility of the company that puts the product on the market, as defined in the Directive; components and sub-assemblies are not responsible for product compliance. Of course, given the fact that the regulation is applied at the homogeneous material level, data on substance concentrations needs to be transferred through the supply chain to the final producer.  An IPC standard has recently been developed and published to facilitate this data exchange, IPC-1752.It is enabled through two PDF forms that are free to use. RoHS applies to these products in the EU whether made within the EU or imported. Certain exemptions apply, and these are updated on occasion by the EU. The RoHS 2 directive (2011/65/EU) is an evolution of the original directive and became law on 21 July 2011 and took effect 2 January 2013. It addresses the same substances as the original directive while improving regulatory conditions and legal clarity. It requires periodic reevaluations that facilitate gradual broadening of its requirements to cover additional electronic and electrical equipment, cables and spare parts. The CE logo now indicates compliance and RoHS 2 declaration of conformity is now detailed (see below). In 2012, a final report from the European Commission revealed that some EU Member States considered all toys under the scope of the primary RoHS Directive 2002/95/EC, irrespective of whether their primary or secondary functions were using electric currents or electromagnetic fields. From the implementation of RoHS 2 or RoHS Recast Directive 2011/65/EU on, all the concerned Member States will have to comply with the new regulation. The bottom line—it remains a complex world and global issues abound.  These issues affect companies trying to market and sell their products to countries far and wide.  We will not be successful unless we “play their game”.  Maybe that’s as it should be.  I welcome your comments.

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