Mechatronics and Economic Recovery

Mechatronics is a major driver in economic recovery.  That may sound like an extreme claim, but it is something I experience with some regularity.  Every time someone comes up with a better solution for a process or new way to make a piece of machinery, there is economic recovery.

Mechatronics doesn’t get the attention of the President of the United States.  Maybe it should.  But the American economy is affected every time someone develops a new process or machine.  It just doesn’t make the headlines every time.

When companies compete for and wind marketsthare based on sales of machinery that others use in manufacturing.  The company that produces increased throughput or new features and benefits adds values to its customers’ operations.   And to the extent that machinery suppliers can capture that value for their customer, they their market, revenue and employment.

Mechatronics is what drives low prices for your favorite can of beer or soda that costs only pennies.  From the high impact can maker that runs a snappy 240 cans a minute, to the pallitizing machines that load 80 cases of your favorite beverage in less than two minutes ready to ship out on a truck.  All that productivity comes from mechatronics.

As the discipline of mechatronic engineering matures, the cost of that technology continues to decline creating new opportunities to drive new improvement with that technology in many different industries.  Better motion control technology means higher speed, higher accuracy, reduced waste, ongoing reduction in complexity and decreased commissioning cost.  All of which leads to new products, markets and economies.

Recently several suppliers like National Instrument and Rockwell have developed the interface between the design phase of mechatronics and the deployment of hardware.  This new frontier is the simulation realm where engineers can simulate and iterate their design ideas in software extensions of the solid model environment.  This development, while relatively recent, integrates the mechanical design environment with the applied aspects of mechatronics.  And in doing so, simulation gives engineers the tools to quickly perform complete design iterations in a few hours, without the need for expensive hardware iterations, lowering the cost of design and increasing the performance of the results.

More and better motion control means new opportunities to grow the economy.  Growing the economy is what we do best.  So keep those great mechatronic products coming.  They are more important than ever.

American Entrepreneurship 101

In my travels, I continue to find people hard at work doing something that has never been done before.  With the hope of making a profit while doing it.  Just such a situation came up recently when I met with the owner and founder of Transcon Steel.

Among the mainstays of an industrial economy is construction, housing and commercial in particular.  While these industries are incredibly competitive, there is always room for innovation.  Precisely because it is a mature, competitive industry, really ground breaking solutions are sometime hard to find.

Transcon Steel is a small startup company in Georgetown Texas that makes structural steel building systems.  The innovation comes from the fact that Transcon roll forms flat sheet metal into structural shapes that are highly optimized to reduce weight and increase strength.  The steel structural shapes are formed into large panels with compressed foam which results in structures that are super light weight and extremely high strength.

The new structural panels permit construction of buildings in a variety of applications.  So called “temporary housing” for oilfield crews in remote area can be built in hours instead of days.  Heating and cooling costs are a fraction of conventional structures.  All of which leads to increased opportunities to serve unique construction applications with better solutions.

Transcon’s big challenge will be to create the manufacturing resources needed to produce the structural panels in very large numbers.  The enabling technology of the manufacturing processes?  Mechatronics. The roll forming of sheet metal is a classic application requiring high performance drives to de-reel the strip steel rolls and servo actuators to follow the roll throughout the various forming process that take place to make the final product.

The compressed foam requires unique tooling to form large rectangular panels that can be filled with foam, compressed with hydraulic actuators and cured with heat and pressure to form the final super dense structures.  Amazingly, the cores are made from material that is similar to the conventional styrofoam cups we use for coffee, yet, when the basic material is processed correctly, it becomes strong enough to withstand blows from a sledgehammer.  When it is bonded to an already strong steel frame, you have a complete building system that has incredible structural strength and insulation value.

Transon is negotiating enough new business that it will need a new facility 4 times the size of it’s present location and will hire CAD designers and plant personnel to support it’s manufacturing needs.  If they are successful at marketing the technology in other countries, it will be more of the same.  Lots of it.

And that is how job creation is done.  Someone with an idea, willing to work hard, taking risks, finding people to come alongside and help, to deliver a solution.  Making lives better by employing people, and by delivering a product that provides shelter at a lower cost than the traditional products in the building market.

American Entrepreneurship.

Doing More In the US

The old business school motto, doing more with less, can have some interesting applications.    American manufacturing is going through a renaissance of sorts.  Across many industries there are substantial efforts to bring more manufacturing back to the US.

A lot of it is precisely ‘doing more with less’.  How do we make the same quality of parts at prices low enough to compete with foreign competition?  It’s not easy when the typical pay scale for manufacturing labor is $8 a day in some parts of the world.

There are a couple of obvious components to price competition that don’t get a lot of attention.  Scrap rates and delivered cost.  When a US company buys parts from offshore, any defective parts are very costly.  The direct shipping cost, duties and processing fees are additional and can be 10-15%.

During my years at Rockwell Automation, we investigated the cost of selling US products in different parts of the world.  Depending on where in the world we are talking about, the shipping and logistics can accumulate between 25 and 40% additional cost to the product being sold.

So the cost of scraps and logistics are the minimum cost hurdles for companies seeking to export their products to the US.  Low cost producers have to make parts cheaply enough that the landed cost and scrap rates cost out less than the price of producing them in the US.

Doing more manufacturing in the US requires finding creative ways to lower costs.  That is the second area that is undergoing change.  American manufacturing technology is finding ways to reduce machinery and process costs.  And this area of effort may provide key strategies that will help the US gain back ground in the pursuit of more world class manufacturing.

Innovation processes like additive manufacturing allow fabrication of metal parts with no machining.  For higher levels of precision there are new machine tools that can do final machining to less than 0.001″ accuracy and the costs of machine tools are lower than ever.  These are the keys to producing high quality parts at lower costs.

There are unique mechatronic solutions that can improve machinery performance across a wide range of applications.  The Acme screw which is very inexpensive, has limited accuracy but plenty of torque handling capability.  What happens if you can add a very inexpensive linear feedback technology to the simple low cost Acme screw?  You get a really high resolution linear motion system that is very inexpensive.

The great news is that these products are currently available.  And that means that making better machines that make better parts at lower cost is practical, achievable and there are no technical challenges.  Common off the shelf parts will get it done.

Servo or Drive?

When does a rotating load require a drive or a servo?  I run into this issue on a weekly basis.  Everyone has their own answer.   As much as this may be a matter of opinion for most people, there are some guidelines that can help make this question more straightforward.

Some people define servo’s as closed loop versus drives which are open loop.  The term servo does require that there is a feedback device to provide the loop closure.  But there are many AC drive vendors making closed loop inverters to enhance the performance of the motor.  AC drives with feedback are generally used where positioning is required.  So the feedback element is not the determining factor for defining if an application is AC or DC.

The overall power level may define one versus the other, but not always.  Brushless servo motors are generally limited to 7″ or 8″ diameter and an equivalent horsepower rating of 20-30 horsepower.  There are frameless motors with even higher horsepower ratings.  But  the size and power rating are strictly a function of manufacturing and marketing constraints.  For a major manufacturer, the question is really, how many motors of a given size are we going to sell?  Based on the high cost of Neodymium permanent magnets, a larger servomotor is going to be very expensive.

But overall power ratings are not limited when you consider products from specialty companies like Powertec.  Powertec takes standard AC motor frame designs and increases the power density by adding embedded permanent magnets on the rotor.  Since the magnets are Ferrite, which aren’t as expensive, they are much more economical and allow designs as big as 400HP.  So power level by itself doesn’t determine what technology to use.

The real answer is in the load conditions.  What is the dynamic response required for the target application?  The rate of change of the load is the key.  Most AC drives are specified in terms of the frequency response or dynamic response of the power electronics.  This important parameter is expressed in Hertz.

Dynamic response is the ability of the drive to regulate speed when the load varies.  The load torque can change significantly, usually 90-100%, and the drive will recover the set speed within the time defined by the dynamic response.  Typically, an open loop AC drive has a 10 hertz dynamic response, which means that it will regulate to 1/10th of a second.

AC drive technology has improved to the point where dynamic response can reach 200 Hertz when a rotary encoder is added to the motor.  This means the drive can regulate load variations wiithin 5 milliseconds.  Which is pretty fast when the load mass is high enough to require a motor of 25 horsepower or larger.

The basic physics are simply that the bigger the load, the slower the dynamic response.  You just can’t make a ton of rotating mass change speed really quickly.  And that’s how the controls should respond.

Nippon Pulse Introduces Green Drive Linear Actuator

Nippon Pulse has announced the introduction of its newest linear servo product, the Green Drive linear actuator. The Green Drive is an all-inclusive linear direct drive actuator suited for high-performance applications requiring high force, accuracy, and precision.

Features of Nippon Pulse’s Green Drive include:

• Acceleration (peak) force of up to 600N for 40 seconds
• Effective stroke lengths between 10mm and 1540mm
• Cooling systems that can increase rated force up to 20%
• Rated force between 13N and 150N
• Position repeatability of ±0.05mm
• T-slots for easy and quick integration into applications
• Position sensors, temperature sensors, interpolation electronics
• Four different feedback output types: analogue SIN/COS, Digital Bus BISS-C, Digital A/B TTL Linedrive Incremental, and Absolute SSI
• Color coded quick connectors
• High-performance slide bearings

The Green Drive currently is available in two sizes, the G16x series and G25x series. The G16x series features a shaft (magnets) with a 16mm diameter and the G25x a 25mm shaft diameter. The G16x series is 66mm wide and high, while the G25x series is 88mm wide and high. Each has varying lengths depending on the required effective stroke.

Nippon Pulse will be highlighting the Green Drive at the ATX West tradeshow in Anaheim, CA in mid-February. Those interested in the Green Drive can visit booth #4348 to learn more about the actuator.

Nippon Pulse America, Inc.
www.nipponpulse.com

Minarik Drives Announces Distribution Agreement with Kaman Industrial Technologies

Minarik Drives is very pleased to announce that it has signed and implemented a National Distribution Agreement with Kaman Industrial Technologies.  This agreement will further enhance a partnership that will provide Minarik Drives with 200 new locations and will provide Kaman Industrial Technologies a premier DC drive and drive systems product line.

“We are very pleased to add Kaman Industrial’s selling capability and the value added approach they brings to their customers to our already strong distribution channel.” said John Hegel, President of Minarik Drives.  “Kaman’s penetration into the user and OEM markets will open doors for us that had been previously inaccessible and will help us serve a greater cross section of business across the U.S.”

Minarik Drives is an independent company that specializes in low to medium power electric drive and power applications.  It has been a standard, and a leader, in the DC drive business for almost 60 years.  With design engineering and manufacturing headquartered in S. Beloit, Illinois, it provides standard and customized solutions at a globally competitive price.  More information about Minarik Drives is available at www.minarikdrives.com or by calling 815-624-5959.

Next Generation Manufacturing

As a follow on to the last post, I have been investigating the cost of manufacturing equipment.  The classic machine tool is the most widely used piece of equipment for fabricating just about anything made out of metal.  The machine tool has been quietly undergoing it’s own revolution since it’s inception in the 1950′s.

The traditional metal cutting machine tool has been around since the 1800′s and was entirely manually operated.  Since the machines were manually operated, the dexterity of the operator became a major factor in accuracy and repeatability of part manufacturing.  Because of the skill required, we still have the term “master machinist” in circulation, even though most machining today is automated.

During the Second World War, the Air Force was confronting the difficulty of manufacturing airplane parts.  Through the work of John Parsons and MIT, the first “punch card” controlled machine tool was built.  Parsons’ company was using early punch card computers to generate a larger number of points along the curve of a wing brace.  The numerical information was then used directly by machinists as a look up table for manually positioning a milling tool.  Parsons realized that if they could motorized the manual process, it could greatly increase the speed of the machining process, lowering costs dramatically and increasing accuracy at the same time.

Gordon Brown’s Servomechanisms group at MIT has recently been working on early forms of closed loop dc motor control for the gun turret on B-29 bombers.  By combining these recent technologies to numerical punch card calculation approach the first Computer Numerical Controlled Machine Tool was demonstrated.

The rest, as they say, is history.  The lessons learned in computer numerical control have been instrumental in every major field of manufacturing.  Cars, electronics, robotics, would not be feasible or cost effective without the underlying control technology of CNC.

Which brings me to a 2 major points as we contemplate the next generation of manufacturing.

Additive manufacturing is maturing rapidly with a wide range of materials, steels and titanium are now available, and precision is improving at the same time.   The surface finish requirements for a large number of parts cannot be achieved with a strictly additive process.  The new wave of additive manufacturing requires a complementary subtractive technology at complementary prices.

Secondly, while there are an increasing number of machine tools at low cost, they are not CNC.  This will likely be the next “breakout” technology.  There are a number of technical hurdles that have to be addressed in terms of reducing the cost to a level comparable with the Makerbot.  With the current generation of dedicated motion controller chips, lower cost step motors and low cost feedback technology, this should be a slam dunk.

Get your pencils out and get after it!  There’s some serious money to be made here.

2012, Year of Opportunity

2011 was a difficult year for many sectors of the US economy.  World markets were about the same as at home.  The general weakness was felt world wide with currencies, especially the dollar and the Euro, declining due to bank failures in EU, financial crises in Greece and Italy, unrest in the Middle east creating concerns about stable supply of oil, runaway spending in the US and low sales numbers in new car sales and new home sales, two of the “bellweather” indicators of economic strength.

Alternative energy in the US has failed to produce the return on investment or to create new jobs in any significant numbers.  Car sales have picked up significantly over 2011, but not nearly at the rate of 16 million cars/year as in the heyday of that industry.  The real estate bubble has burst after a decade of speculation and bad lending practices that continue to depress new construction.

The second industrial revolution, Henry Ford’s industrial revolution, was about mass production and cost reduction.  For almost 100 years we have been perfecting the centralized manufacture of almost everything around us.  Economies of scale that enable volume manufacturing of consumer electronics at lower cost year after year are the result of the Ford approach to manufacturing.

So where do we go from here?  We start re-inventing the industrial revolution.

The new wave of manufacturing has begun with the advent of the Maker Bot and a family of low-cost fabrication tools that can manufacture based on 3D printing techniques.  While solid model prototyping has been around for some time, the magic ingredient is a new family of machines that cost less than $2000. and some recent new entries around the $1000 mark.  At these price points, it doesn’t take a lot of volume to justify the purchase of one of these machines.

There are advanced processes that are becoming available to generate sintered metal parts, even titanium parts, using processes resembling the additive manufacturing process.

Amortization cost is the secret.  Lowering amortization costs and minimum order quantity at the same time results in a fantastic breakthrough in productivity.  It also lowers the barrier to entry into new markets.  So if you have an idea for something that’s never been done before, the cost for development may be a lot lower than you think.  And thousands of people have begun to jump into the mainstream economy because of the availability of these new tools.

While the “maker” tools are limited to plastics, there is progress in the metals arena as well.  The computer numerically controlled (CNC) machine tools have traditionally been the domain of 6 figure costs, HAAS has been making $50,000 machines and last year Tormach entered the market with the “Personal CNC”, a high quality machine that is priced at $10,000.

My prediction?  There is going to be a lot of activity at the $10,000 and below price point to come up with low cost machine tools as a complement to the “maker” bot 3D printer technology.  Additive manufacturing will require a complementary subtractive manufacturing infrastructure at a comparable price point.

And creative American engineers and tinkerers will be leading the way.

Innovation in Motors for Mechatronics

Innovation is the watchword of mechatronics.  The pressure for solutions in alternative energy continue to push the boundaries of design in electromechanical systems.

In the wind energy arena the biggest change has been the shift to direct drive permanent magnet generators.  By eliminating the gear “increaser” to convert the low RPM of the propeller system to a high RPM for a standard high power generator.  This is crucial step in bringing the cost of wind power down. Current systems are weighing in at 100 tons and have to be suspended above water or land 165 feet in order to pick up sufficient wind currents to be economically practical.

There is no single solution that is ideal for wind applications.  One supplier has a generator that is made up of 4 smaller units on a single large ring gear.  This system seems to have significant advantages in reducing the size and weight of the generator and makes maintenance more simple in the event of a failure.

Among the major mechatronic challenges driving change in the motor industry, electric vehicle applications are continually pushing the boundary for energy density and efficiency.  The performance demands of electric vehicles and other mobility applications make every percentage point of efficiency crucial to the range of the target vehicle.  This has led to a rash of new motor and drivetrain designs with a variety performance capabilities.

Each new innovation seeks to organize the basic materials of the electric motor in a new way to improve some aspect of performance.  Electric motors are copper conductors, “soft” magnetic steels and many times, permanent magnets.  The basic costs for copper wire at $5-6 a pound, commodity strip steel is about $.50 per pound but has to be punched in precise shapes, coated with insulation and stacked into larger assemblies, and $16. per pound for permanent magnets.  Complex processes associated with motor manufacturing make motor costs considerable.

In a recent development teams in academia in Australia and the US have developed simple low RPM motor structures based on polymer actuators referred to as “artificial muscle”.  While this development is in its early phases, the simplicity and low cost are significant and very appealing.  A demonstration of the new technology can be seen on YouTube at;  www.youtube.com/watch?v=ZcCPNJR5PCMand it is very much worth the watch.

The only sure thing is that we continue to meet the challenge of new market needs with innovation.

Friction Part 2

An interesting aspect of actuator design popped up in a couple of recent applications.  The efficiency value of the actuator isn’t often the top parameter on the list of things to check when making a selection.  But it should be.  Efficiencies vary wildly, even from the same vendor, and will have signficant impact on the resulting machine design.

Why?  First because losses in the sytem result in friction and heat.  Every time energy is converted from one form to another, there are losses.  In electromechanical systems these losses are most often heat.  If the application has high cycling rates, the heat created by the losses need to be considered.

Acme screws are a great solution that is inexpensive and widely available.    The design parameters for Acme screws are pitch, diameter, material, surface finish and nut.  The most significant issue is the pitch.  At low pitch ratios, the efficiency can be 60% or higher.   At high pitch ratios, like 10:1 lead, the efficiency of some Acme screws can be very low, 35-40%.  When thermoplastic materials are used for the drive element, the efficiency becomes a critical issue.  The efficiency translates as heat, with high cycling the heat will cause deflection in the material that can make for added difficulty in the actuator.

A recent project I worked on had a screw with 35% efficiency, which means that 2/3 of the power into the mechanism was being dissipated as heat.  Not a good situation when the load is moving constantly or at high speed.  As the parts heat up, the polymer nut finally heated up to the point where it melted.  By changing the drive train to a planetary gear reducer and a screw with low pitch, the screw becomes a low speed actuator with double the efficiency, cutting the load requirement and heating in half.

In ball screw actuators, the circulating ball bearings and lubricant reduce the friction dramatically regardless of pitch.  Some ball screw actuators are 99% efficient, so there are no significant issues to consider in the losses.  The increased efficiency comes at a substantial price, but it also comes with high precision.  So for high precision actuators, the ball screw is a natural choice.

Rolling bearing actuators are another solution to linear motion, which also have incredibly high efficiency.  There are many vendors using rolling bearings of various configurations.  With low coefficients of friction of 0.2%, rolling bearings are an incredibly efficient solution at a very low cost.  Most often the rolling bearing systems are driven by belt and pulley systems which are also very efficient.

Again, frictional considerations become very significant in subtle ways.  Early evaluation can insure higher performance and lower cost in many designs.

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