My Engineering Blog

If you had your teeth straightened 50 years ago, instead of the brackets being cemented on teeth, every tooth had bands around it. The arch wires were thick, and adjustments were made by tightening the wires that held each tooth. Over the course of the next two weeks the tooth moved, lessening the force to practically nothing, and the patient went back to the orthodontist and did it all again. The problem with this approach is that moving a tooth too rapidly kills it. Even if the orthodontist was very careful, patients found that they had very sore mouths for several days after they got their braces adjusted. It might have worked well if the patient could have gone to the orthodontist to get the tension on his braces adjusted every few days, but seeing a patient that often wasn’t economically feasible for the orthodintist.

Through research using load cells to detect pressure necessary to straighten teeth, orthodontists have shown that mild pressure applied constantly achieves faster and far more comfortable tooth movement with little danger to the actual health of the tooth. One such study investigated how to straighten teeth using very light forces as measured by a very tiny load cell for tooth movement in rats.

Another area of development in how to straighten teeth has been new and improved bonding agents that have allowed brackets to be glued onto each tooth rather than using the bands that completely encircled each tooth. As a bonding agent cures, it contracts. This can be a problem because obviously greater contraction stress can adversely affect the bond strength, which might lead to the tooth bracket popping off. Contraction stress as bonding agents cure has been investigated with the use of load cells to determine the stresses generated by the curing process. Orthodontists have used this information to determine the best bonding agent to straighten teeth.

New materials such as the lightweight tooth moving wires developed through NASA, stronger and lighter metals, and better bonding agents have changed how orthodontists straighten teeth. People find that todays high-tech materials are more comfortable, and there are many new designs in orthodontic appliances and braces.

The bathroom scale is a modern convenience. Even as late as a century ago, a scale was far too large and heavy to be included in the furnishings for a bathroom. The first coin operated scale was brought to the US from Germany in 1885. A few years later, in 1889, the National Scale Company manufactured the first coin operated scale in the United States. It was huge, weighing more than 200 pounds, but the coin operated scale was one of the first automatic vending machines. Drop in a penny, and you got to see your weight.

The idea of a vending machine caught on. During the 1920s and 1930s the Peerless Scale Company coin operated a coin operated scale on almost every corner. In the 1920’s and 30’s, weighing youself was a novelty, and since people always had a penny, even in the middle of the depression, they could always afford to weigh themselves. Back then owning a coin operated scale was a great business. In a good location, a coin operated scale collecting one penny at a time could earn $50 to $100 a month. Even in a poor location, a coint operated scale could bring in $5 a month. Since a scale cost only $50, the profit margin was pretty good.

The popularity of penny scales reached its pinnacle in the mid-1930’s, when there were over 750,000 scales all across the country. As the novelty of the coin operated scale diminished, new gimmicks were designed to revitalize interest. Some scales were designed to give a small ticket with a person’s weight printed on it (so that people could hide their weight from viewers and husbands). Then, fortunes were added to the tickets and before long pictures of movie stars were used to encourage patrons to collect tickets and complete a set. The movie stars paid the coin operated scale companies to feature their pictures in order to promote their names.

In the 1940’s, improvements in mechanical scale technology made the small inexpensive personal bathroom scale readily available, and the popularity of the coil operated scales began to decline.

Today, the personal bathroom scale is more likely to be digital. load cell technology has made the bathroom scale very accurate — even ones small enough to fit in a suitcase for travel. In 2004 a patent was granted for a bathroom scale that mounts into a floor, and that is designed to have tiles or other floor covering materials on top of it. Weight information is transmitted from the bathroom scale to a remote countertop or wall mounted display which may normally show a clock or something else until the bathroom scale is stepped on.

The fact is that the airbag is dangerous, and we have been systematically lied to about how very dangerous the airbag that we are all forced to drive around with actually is. The Department of Emergency Medicine at the University of Louisville and the Kentucky medical Examiner’s Office have been conducting an on-going study over the past 10 years of airbag injuries and airbag death. They have found not only that a driver or passenger close to a deploying airbag can sustain severe injuries or death, but also that having the chest, arm, or face close to the deploying air bag or module cover can result in extreme airbag injuries such as amputation of fingers, hands and forearms, pulverized compound fractures of the forearms and fractures of the upper arms, no matter what the speed of the car is.

The government appears to finally be doing something about the airbag injuries and airbag death. They have adopted new regulations requiring airbag testing with children and small adults, something that should of course have been part of the original testing requirements. Hopefully by the government’s deadline, 2012, auto manufacturers will have in place an airbag that is controlled by load cells that sense the size and position of car occupants. Until then it is up to us to try to protect ourselves.

Here is a list of groups the government thinks are at risk:

1. Drivers who sit within 10 inches of the steering wheel are at high risk for airbag injuries or airbag death. This includes

• people about 5′4″ or shorter
• heavier people
• pregnant women

2. Those with medical conditions such as those with Osteoporosis or Tinnitus are at risk of airbag injuries.
3. Children who need to ride in the front seat are especially at risk of airbag injuries or airbag death:

• in cars, trucks or vans that have no back seat
• when a child or infant can’t be adequately monitored in back
• when the front seat is needed, as with a carpool.

What can we do? One thing is to turn the airbags off. If you, or your expected passengers fit into these listed airbag endangered groups, you can apply to the National Highway Traffic Safety Administration for permission to have an airbag switch installed.

In 1998, soccer injuries sent more than 77,500 children and adolescents ages 5 to 14 to hospital emergency rooms. The Consumer Product Safety Commission, over a 13 year time period, identified 18 individuals who have died from soccer injuries: specifically from head injury resulting from impact with the goal post. Kid sized crash dummies are helping analyze a padded system for the goal post which will hopefully aid in the prevention of head injury in soccer. The idea is that a machine accelerates a carriage and a Humanoid head form along the steel track until an impact occurs with an instrumented anvil at the end of the track. A load cell within the anvil is used to measure the force of the impact and determine what head injury that would occur.

Head injuries aren’t the only soccer injuries. The shin is the third most common soccer injury, and injuries to the shin most often occur when players try to kick the ball and instead kick each other. A study performed at the Institute for Preventative Sports Medicine in Ann Arbor, Michigan found that Shin guards significantly reduced soccer injuries by reducing the force delivered by a kick to the leg by 41.2 to 77.1 percent.

Researchers wanted to simulate soccer injuries that result from one person kicking another person with their leg planted. They wanted to make sure their test setup could achieve the impact a healthy, physically active athlete could deliver with a kick. To do this simulation, the researchers used a Hybrid III crash dummy which is similar in size to a ten-year-old child. the Hybrid III dummy measures more factors and more closely mimics whole body responses of humans than other approaches. The researchers fitted the shin guards to the leg with straps in the manner in which a player would typically attach the guard. Then a free swinging pendulum device delivered a force similar to that of a high impact collision during a game to the knee of the dummy. The force of the ‘kick’ was recorded by a load cell in the dummy’s knee, and from this information the researchers were able to determine what soccer injuries were likely to have resulted from the kick.

22 different commercially available shin guards were tested. The study found that all shin guards demonstrated at least a 40 percent reduction in the force delivered with several shin guards reducing the force over 70 percent. The good news is that even the least effective shin guards were able to significantly reduce soccer injuries.

Thanks Crash Dummy Kids. I’m hoping the results of this test will be posted next to the soccer equipment at my local sporting goods store.

Motorcycles are being designed with greater functionality, higher performance, and higher speed. The motorcycle test rider must be highly skilled because the rider himself, his body type, his position, as well as the repeatability of his actions affect the usefulness of the test. Not to mention that in order to test the motorcycle at the edges of its capability, there is a possibility of injury for the test rider. In order to solve these problems–repeatability of tests and possibility of injury–The use of some sort of remote control comes to mind. After all, every little boy has probably driven a small scale remote control motorcycle. But simply wiring up the motorcycle itself to a remote controller isn’t the answer because electronic response isn’t all that is being tested. The tests require a human shape and weight on the cycle, plus part of the test is control pressure and responsiveness. The answer is a human shaped motorcycle riding robot.

In 2002, Yahama Motor began using a control system for automated testing of their motorcycles by a human-shaped robot. In this measurement system, the anthropomorphic robot controls the accelerator, shift, and clutch operations on a driving test bench.

The robot rides the motorcycle in a wind tunnel. The motorcycle stays on the chassis dynamo and wind flows from front to back of the cycle at the same speed as the running speed of the cycle. The driving patterns can be controlled automatically using the built-in driving programs, so the operator only has to press the start button in the operation room to have the robot carry out the evaluation test. The control data gives drive commands to the robot, and sets the environment and load conditions. As the test progresses, the driving status and data from load cells are recorded.

in 1883 the eminent biologist T. H. Huxley said “In relation to our present modes of fishing,” , “a number of the most important sea fisheries, such as the cod fishery are inexhaustible.” He couldn’t have been more wrong. The facts are that the United Nations Food and Agricultural Organization reports Twenty-eight percent of fish stocks worldwide are overfished or even nearing extinction, and another 47 percent are near the limits of sustainability. the US National Oceanic and Atmospheric Administration reports that a third of fish stocks in US waters are in danger of depletion. To make matters worse, fish consumption has doubled between 2973 and 2997.

The answer to this delimma is open ocean aquaculture — a fish farm, or raising fish in farms whose environment is the ocean itself. The United States is strongly the development of open ocean aquaculture farms. Open ocean fish farming has been done in the US for salmon, and in Europe and the Mediterranean, sometimes with mixed results that included many escaped fish. Because of fish farm problems in the past, extensive testing has been done in order to evaluate the environmental impact of the open ocean artificial fish farm and even whether the fish caging devices were strong enough to withstand the rough offshore waters. Once in place the effects of currents and storms on the cages were masured. load cells were deployed with the mooring to measure tension in the mooring lines, and low power recording systems were deployed on the load cell mounting bars by divers.

The open ocean aquaculture test location in Hawaii, about 2 miles off Ewa Beach on Oahu, showed no measurable impact to water quality or the ocean floor once one was a few hundred feet from the cage. It was determined that the low impact of the fish farm was due to feeding method, which was twice a day so that very little food reached the ocean floor, and to locating the fish farm in offshore waters where there is an adequate current to carry waste products away from the site.

The US is not the only nation which is initiating open ocean aquaculture as a solution to the growing divergence between the need for fish and the wild fish population. Open ocean aquaculture operations are located coast to coast in the US, Canada, Mexico, Australia, Japan, the Philippines, India, Tailand, Vietnam, and most of South America, Egypt, India, China, and Europe.

Cooking on the moon offers some interesting challenges. It isn’t as simple as Space Family Robinson setting up a picnic table, firing up the barbeque pit, and throwing on some hamburgers. First, if they were planning an outdoor supper, the entire Robinson family would be in space suits. Hard to imagine how they would eat a hamburger through the face shield. OK, so maybe they cook outside then go into their space ship to eat?

Well, probably not. For one thing, they definitely wouldn’t be lighting up the charcoal — no air, no fire, but how about cooking on an electric grill? That might work to get things hot — but whatever they were trying to cook would be really really dry. Why? Because there is no air, and therefore no air pressure. As the ambient pressure goes down, the boiling point of water goes down. Zero atmospheric pressure equals immediate water boiling! Water, or moisture in hamburger meat, would rapidly boil away into space on the sunlit side of the Moon, which is very very hot from direct solar exposure, or form very fine ice crystals in the shadow side, which is hundreds of degrees below zero. When they tried to heat the meat to cook it, the water would evaporate.

With that sort of harsh environment, the Family Robinson decides to cook and eat on their pressurized, temperature controlled spaceship, and since the cook-hamburgers-on-the-grill idea has been nixed, Mrs. Robinson decides to make steak and biscuits. She brought along her precious Earth cookbook and her digital kitchen scale with its super accurate load cell technology. Her cookbook tells her that to make a dozen biscuits, she needs 10 oz. of flour. She sets up her scale and scooping flour into the scale’s bowl. She keeps adding flour, thinking that this is a lot more flour than she remembers using back on Earth. When the scale reads 10 oz, the bowl is nearly full, and she remembers that on the moon, things weigh about 1/6 of what they weigh on Earth, so she pours the flour back into the flour container (very gently because since it’s so light, it is really easy to end up with flour dust all over the kitchen!). She realizes that she could simply measure the volume of ingredients but she has no measuring cups, so she divides the required weight of flour by 6. This time when she puts flour into the scale bowl, she is looking for 10/6 or one and two-thirds oz. When the scale reads one and two-thirds ounce, it looks like she has about the right amount of flour.

Next, Mrs. Robinson questions how hot the oven needs to be to cook on the moon. She knows that when cooking at high altitudes water boils at a lower temperature so things like rice take a lot longer to cook (unless you have a pressure cooker). However, changes in altitude do not affect oven temperatures, but baking items often rise quicker at higher altitudes, so it is necessary to increase the oven temperature. Fortunately, she is cooking in a pressurized space ship, so that will not be necessary for this batch of biscuits. After supper Mrs. Robinson sits down at her computer to browse the internet for a kitchen scale that offers special conversions based on what planet they find themselves.

Martial Arts has been an island of traditional purity surrounded by a sea of technology. Martial Arts practitioners have focused on mental and emotional discipline as well as physical training, preserving their particular fighting system’s centuries-long legacy. Measuring the strength of a blow isn’t a new idea. The automobile industry has been doing if for decades, but It isn’t surprising that traditional martial arts have been slow to adopt technology. Despite that reticence, martial artists are now readily utilizing advanced load cell sensors that have become small enough and flexible enough to be sewn into the protective padding. After all, anyone who has ever hit a punching bag wonders just how hard he is really able to hit. Now technology makes that possible

Today s Martial Arts academies advertise high technology gear such as focus pads (electronic force measuring pads) along with their free standing kick bags, body opponent bags, stretching machines, and traditional wooden dummies. In fact, sensor technology has made its way from the martial arts training ring to the tournament arena. Tae Kwon Do now allows the use of force sensors in tournaments. 2006 Olympic Tae Kwon Do rules state: “In the use of electronic trunk protectors….Valid points scored on the mid-section of the trunk shall be recorded automatically by the transmitter in the electronic trunk protector.”

Evidence of the degree to which sensor technology has been accepted into the martial arts was provided by The National Geographic Channel’s program ‘Fight Science which aired in August 2006. A $150,000 government-certified crash-test dummy known as the Hybrid III anthropomorphic test device. outfitted with sensors and measurement capabilities created especially for this research, allowed scientists to measure the impact of blows, throws, and kicks, providing data that frequently astounded the scientists. This was a highly intelligent show which brought together a team of crash test scientists, sports biomechanists and Hollywood animators with a cross-section of the world’s top martial artists representing various styles of martial arts in an attempt to separate martial arts fact from fiction. What they found was fact, something which can only increase the technology hungry public’s appreciation for martial arts.

in 1883 the eminent biologist T. H. Huxley said “In relation to our present modes of fishing,” , “a number of the most important sea fisheries, such as the cod fishery are inexhaustible.” He couldn’t have been more wrong. The facts are that the United Nations Food and Agricultural Organization reports Twenty-eight percent of fish stocks worldwide are overfished or even nearing extinction, and another 47 percent are near the limits of sustainability. the US National Oceanic and Atmospheric Administration reports that a third of fish stocks in US waters are in danger of depletion. To make matters worse, fish consumption has doubled between 2973 and 2997.

The answer to this delimma is open ocean aquaculture — a fish farm, or raising fish in farms whose environment is the ocean itself. The United States is strongly the development of open ocean aquaculture farms. Open ocean fish farming has been done in the US for salmon, and in Europe and the Mediterranean, sometimes with mixed results that included many escaped fish. Because of fish farm problems in the past, extensive testing has been done in order to evaluate the environmental impact of the open ocean artificial fish farm and even whether the fish caging devices were strong enough to withstand the rough offshore waters. Once in place the effects of currents and storms on the cages were masured. load cells were deployed with the mooring to measure tension in the mooring lines, and low power recording systems were deployed on the load cell mounting bars by divers.

The open ocean aquaculture test location in Hawaii, about 2 miles off Ewa Beach on Oahu, showed no measurable impact to water quality or the ocean floor once one was a few hundred feet from the cage. It was determined that the low impact of the fish farm was due to feeding method, which was twice a day so that very little food reached the ocean floor, and to locating the fish farm in offshore waters where there is an adequate current to carry waste products away from the site.

The US is not the only nation which is initiating open ocean aquaculture as a solution to the growing divergence between the need for fish and the wild fish population. Open ocean aquaculture operations are located coast to coast in the US, Canada, Mexico, Australia, Japan, the Philippines, India, Tailand, Vietnam, and most of South America, Egypt, India, China, and Europe.

The overwhealming reason to measure recipe ingredients by weight instead of by volume is precision and repeatability. If you measure by weight, the amount of a particular ingredient is not affected by how tightly it is packed, how finely it is chopped, whether it is a large, medium, or small item, whether it is precisely leveled in the measuring cup, which country your measuring cup comes from (U.S.cup = 237 milliliters, U.K.cup = 284 milliliters, and Australia cup= 250 milliliters), or what brand of flour you are using. The number one complaint of home cooks is that they followed a recipe, but it didn’t turn out. The reason is that while they used the same number of cups of each ingredient as the recipe author, they actually used a different amount. If you have experienced this frustration first hand, and are now ready to try a modern digital kitchen scale using the latest load cell technology, you still need to knowhow to use your kitchen scale effectively.

Before doing anything else with your kitchen scale, you must tare it properly. Taring means eliminating the weight of the scales’s bowl from the weight of the food item it contains. Put the empty bowl on the scale by itself. On digital scales this is trivially easy–there will be a tare button which will reset the scale to zero.

Once you are ready to use your scale, you may find it difficult to find recipes that list ingredients by weight instead of volume. If you have a cookbook published in Europe, this is no problem. It is common in Europe to measure dry ingredients by weight and liquid ingredients by volume. But if you live in the United States, you already know that cookbooks usually list ingredients by volume. What do you do?

Of course you could purchase a European cookbook. The downside to this is that it may not contain the recipes you want, and if you have been cooking for any length of time, you probably have notes written around your favorite recipes detailing variations that you do not want to lose. Here’s how you can convert recipes that call for cup measures to more reliable and repeatable weight-based recipes. This approach assumes that you have tried and were satisfied with the recipe. Converting your ingredients to weight will make sure that the recipe will turn out the same every single time you make it, and has the added benefit of making sure that anyone you share the recipe with, will get the same results you do.

To convert a recipe, fill your cup measure with the same two cups of flour you always use, packed exactly as you always pack it, and then dump it into a pre-tared weighing bowl on your scale and note the weight on the original recipe. Repeat for each dry ingredient. Now you are done because liquids are best measured by volume anyway. If your recipe doesn’t come out quite right, no problem. You still know exactly how much of each ingredient you used in the botched attempt. It’s much easier to use a little more or less of a particular ingredient when you know precisely how much you used before. With the variation inherent in cup measures, this would be almost impossible.

Weighing each ingredient as you go is not the only way to determine their weight. If you cook more by appearance and texture than by weight, adding a few extra tablespoons of this ingredient or that, you can still figure out how much of each ingredient you used by using the difference method.

First gather your ingredients, leaving them in their storage containers. Now weigh each container. Don’t worry about taring the scale with an empty container first; just record the weight of the container with its contents.

Next, actually cook your dish. After you have finished cooking, assuming you like the results, weigh each of the ingredient storage containers again. Subtract the after-cooking weight of each container from the before-cooking weight to determine how much of the ingredient you used.

The difference method is also great for reconstructing secret or unknown recipes, like your grandma’s famous cornbread. She may not use a recipe at all, or it may be one that only makes sense to her. It may call for 2 regular scoops of flour, but only she knows which scoop that means and how to pack it. If you weigh her flour before and after the biscuit making, you’ll know exactly how much she uses.

Using a kitchen scale not only makes it possible to recreate a recipe precisely as you made if before, it can save you some time. The idea is that instead of pouring each ingredient out of the weighing bowl into your mixing bowl after weighing, you simply re-tare the scale and load the next ingredient right on top.

Now that you have your favorite recipes converted to weight-based recipes, you can get excited about making your grandma’s famous cornbread and be pretty certain that it is going to come out right.