Operating in a Vacuum

Semiconductor machinery poses some of the biggest challenges in the entire field of motion control.   Typical requirements in semiconductor machinery applications start with nanometer accuracy which is daunting for most forms of motion controls and actuators.  Add to that, operation at 10 to the -9 torr hard vacuum, and you have some of the exotic machinery in the world.

Initially the vacuum rating doesn’t seem like it would be a major factor, after all, motors operate on the basis of magnetism, and magnetic circuits are fine in a vacuum.  All true.  Ironically, it’s all the other stuff that doesn’t work.  The list is long.

Hard vacuum causes materials to outgas and and stray molecules of whatever, especially if it’s metallic, may create an unwanted current flow causing the device to fail.  A large number of impurities can ruin an entire wafer whose cost may be $25,000, $50,000 and higher.  So absolute chemical purity in vacuum operations is required, and the procedures and costs for achieving this high level of “clean room” performance are complex and expensive.

With standard electromagnetic motors, operation in a vacuum is a problem because the materials themselves are difficult to make clean enough to prevent outgassing of contaminants.  The most obvious material problem being bearing grease, and since there are two bearings required in any rotary motor, this is an issue.  Ceramic bearings with no lubrication can be used, but they are expensive.

The list goes on from there.  Magnet wire coatings, lamination coatings, drip insulation on the windings, magnet bonders.  All these materials would have to be tested for outgassing at vacuum.   Since many semiconductor processes occur in the range of 300 degrees centigrade, far beyond the range of conventional insulation systems, alternative insulation materials would require testing at high temperature as well.  More expensive.

The other problem with vacuum technology is that there is no place for heat to go.  Heat in the motor has to be dissipated, regardless of what type of motor it is.  The application load conditions would have to be rated on the basis of conducted thermal loss because there is no radiated thermal path available.  More cost.

This is not to say that electromagnetic solutions cannot be implemented.  They can, and there are companies that specialize in the construction of custom motors and actuators that are clean room rated specifically for the semiconductor industry.  This makes sense based on the fact that semiconductor capital equipment is a $38 billion worldwide industry.

But, there are other options.  Piezoelectric actuators from Nanomotion are made from high purity aluminum oxide ceramic are available off the shelf that can perform both linear and rotary motion with only 1 moving part.  Piezoelectric actuators have an incredible power to weight ration of 4:1 and when there is no power applied to the moving element, it acts as a brake to hold the load in place.  These are almost ideal characteristics for motion control applications.  And because these motors are extremely efficient, thermal management is rarely an issue.

Piezo actuators are designed specifically to operate in hard vacuum and ultra high vacuum conditions reliably for years.  And with Nanomotion’s 20+ year history in semiconductor applications, they make it look easy.

Medicine and Mechatronics

My wife had surgery recently.  We were told the surgery would be done robotically with a DaVinci surgical system.  Fortunately, the condition for which she is being treated appears to be resolved by the surgery.  But the events give me pause to contemplate the role of mechatronics in modern medicine.

I remember reading for many years about the development effort going into robotic surgery.  Incredible effort to develop touch sensitive servo controlled actuators with force feedback that have the dexterity of the most skilled surgeon.  These systems were complex, multi-axis motion control systems that were developed where force feedback technology didn’t exist.  A lot of it had to be invented for the first time.

And all the many hours of effort paid off.  These systems perform incredibly well.  They make possible complex surgery that can be done more quickly, more efficiently and with significantly less patient trauma that conventional surgical methods.

But the relationship between medicine and mechatronics is incredibly more broad that just robotic surgery. The human genome project could not exist without high speed actuators to speed up the process of chemical analysis.  Almost all forms of biological screening and chemical testing requires the use of 3 axis Cartesian gantry robots that are referred to as Lab Automation Robots.  They are used to process trays of up to 96 samples at a time and perform thousands of tests automatically.

Then there’s the MRI and CAT Scan machines.  Do you know why they are shrouded in white plastic covers?  Because if you could actually see the 2 meter diameter, 2000 pound scanner inside the covers that is spinning at 300 rpm around your body, you probably would not sit still long enough to get the imaging work done.  In addition to the complexity of scanning and sensing the human body in extraordinary detail, the mechatronic challenge of getting the payload to move that much mass at that speed is remarkable.

There are dozens of other examples of the relationship of mechatronics to medicine.  The heart lung machine is simply a set of rather exotic pumps that pump blood and oxygen needed to sustain life during extreme surgery.  High speed sterile packaging machinery prepared precise dosages of medicines in solution at blinding speed and with absolute traceability down to the individual dose.  Sterile saline and sugar solutions used in surgery are made by the carload using every kind of mechatronic solution ever thought of.

No, mechatronics will never replace the incredible science that goes into each of these applications.  But it is a key enabling technology that continues to make possible incredible advances in the field of medicine.

Prototypes and Production

There is a perception that Motion Control technology can be somewhat pricey.   This is a constant challenge to engineers seeking to develop new applications.  The problem is that prototyping a new application may have little or no resemblance to the hardware required in production.  The gap between prototyping and production is quite significant, for a number of very good reasons.

Often, the gap is based on the target production requirement.  Obviously when spindle motors for hard disk drives are being manufactured in the tens of millions, economy of scale helps keep the price low and every opportunity for integration helps drive the cost down.  Some of the most advanced brushless dc controls ever built were created specifically for the hard disk drive motor.

But the massive volume applications are few and far between.  Which means that few applications get the benefit of tens of thousands of man-hours of design.  Application refinement has to be accomplished quickly, generally in no more than 2 revisions.  How much engineering time is available to research unique solutions and investigate novel solutions is limited.  And often, the lead time to production of a new product is defined in weeks or months during which all the issues have to be resolved.

Sometimes the real work is to examine a variety of near term solutions looking for highest reliability at the least cost.  Which is really a challenge.  Reliability can be managed through many different aspects.  One approach is to minimize the number of components.  Is a gearbox going to make the system lower cost or more complex?  Is a brake more reliable than a holding current applied to the load through the motor drive circuit?  These are all questions that should be asked and answered when doing this kind of investigation.  Often the answers seem obvious, but on closer examination, there are interesting tradeoffs that will lead to a great solution.

Then there is the gap between prototype and production.  The time constraint to get testing done and prove a new concept may require that off-the-shelf hardware be used that is not going to be used in production at all.

The production requirement may not be very large, even a few systems a month may justify significant customization of parts to facilitate any of a number of issues.  Reduction in assembly costs, integration costs in the overall structure of the mechanical system, finding ways to eliminate feedback are all part of the engineering equation that comes into play in new product development when mechatronic systems are being developed.

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.

The Next Industrial Revolution

Modern manufacturing is largely the result of Henry Ford’s innovation, assembly line mass production.  The goal of which was primarily to make cars available to large numbers of people due to significantly lowered costs.   No other single innovation has contributed as much to increase the quality of living conditions throughout the world.  Mass production has made more goods available to more people in more places than any other system in the history of mankind.

The electric light, for example, which was coveted 100 years ago as the great solution to night time darkness, making obsolete the candle or gas lamp.  Mass production has made the light bulb an inexpensive  commodity on the verge of extinction at about 25 cents per bulb.  The desire to reduce energy consumption is ushering in the age of the light emitting diode (LED) as the replacement technology for electric light.  Every effort is under way to reduce LED costs by any means possible so that illumination will be available that is even cheaper than incandescent lighting when the energy cost over ten years is factored into the new technology.

Even generating and delivering electricity is the result of applying the principles of mass production.  Large generating facilities are able to generate power cost effectively through economy of scale, selling the power profitably at 4.5 cents per kilowatt hour.  Wire, cable, switching systems and other infrastructure are generally costed in at an additional 2 cents per kilowatt hour to deliver the power to your door.  This is an incredible deal, trillion of dollars of resources at your disposal for pennies.

But mass production is not the answer for every aspect of modern society.  Lowering the cost of mass-produced goods implies that there is a requirement for the sufficient numbers of a product to warrant the investment in the necessary processes and tooling to accomplish the task.

Enter 3D printing technology.  Also known as “Maker bots”, this new class of tools is making fabrication a  new American pastime at incredibly low cost.  Where 3D printing equipment has recently been the domain of well-funded large corporations , selling at $10,000 to $20,000 each, 3D printer kits are available at less than $1000.  And lest you think that these are only toys for boys, the additive manufacturing paradigm has taken hold in the metals industry producing high quality parts in various steel alloys and even in titanium.

Why does it matter?  Because anything that lowers the barrier to market entry for new products creates the opportunity for people to enter a market that was previously inaccessible.  The hidden relationship is financial, it is the cost of amortizing the manufacturing resources across a given number of products that makes startup of a new product impractical.  So barriers to entry in new product development are primarily the result of amortization costs.

What happens when a new technology introduces a significant reduction in the amortization cost?  You get the opportunity to experiment with things because the cost of iterating the design is low.  New products can be test marketed and improvements made because there is no major investment in tooling that would have to be modified in order to change the design.  You don’t have to get it right the first time.

And that means that anything is possible.

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.

Friction, Friend or Foe?

Friction is rarely talked about in motion control circles (pun intended for those paying attention).  It is the “waste” energy in mechanical systems.  We spend a lot of time and sometimes cost, trying to eliminate it.  Many times we just ignore it.

This was the case when a friend of mine was designing a material handling system for newspaper bundles.  A very exotic conveyor system with 8 servo driven belts and a design that involved 10 pages of hand calculations of inertia.  We shipped the servos and sent out a field engineer to start up the project only to find out that the motors and drives were too small.  The designer had forgotten to account for friction.  In this case the frictional load was 3 times the mechanical load due to the unique belt and roller configuration.

So the first lesson is; don’t forget to look at friction as 1 of 3 components of the torque load.  The three being; steady state torque, torque of acceleration and friction.

Then there is the fanciful wishing that there wasn’t any friction to worry about.  Kind of like doing experiments in the space station and having no gravity.  It’s fun to think about, but there are few real world situations where this is likely to work.  The only exception is air bearings.  Of which there are a few.

If you have ever played air hockey, air bearings are like that.  Parts in motion tend to stay in motion when there is no friction to worry about.  And that would be good in a lot of applications.  No friction will generally result in smaller servos, so there are savings in the hardware requirement.  No friction means no mechanical wear, nothing to service as the machine runs up cycles.  No friction also means high speed motion is a lot easier to achieve.

Cars coast to a stop because of friction.  That’s a good thing.  Without friction, parts would end up flying off the conveyor instead of going where you want them to go.  In conveyor belt applications there is usually a lot of friction and that helps the system slow down and stop.

So the second lesson is; friction can be your friend.

In between systems with friction and systems with no friction, there are rolling bearings.  Systems like the Bishop Wisecarver “Vee Guide” are among many products on the market are examples of this.  Rolling element bearings have very low coefficients of friction, so losses are low and therefore the energy needed to overcome them is very low.  This also results in very low wear, so maintenance on this type of mechanism is also low.

The are dozens of linear actuators on the market and each vendor has developed unique bearing solutions, whether sliding or rolling, that perform well at varying price points.  There are no universal rules for selection.  The typical criteria are move speed, positioning accuracy, life expectancy and cost.

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