EPSON Robots introduces New EPSON G1 Mini SCARA Robots

Carson, CA – EPSON Robots introduces the new EPSON G1 Mini SCARA Robots. Leading the industry with best in class cycle rates, precision assembly and motion range, EPSON G1 robots provide an ultra compact yet powerful solution for even the most demanding applications.

G1 Mini SCARA robots are available in arm reaches of 175 or 225mm. They are also available in Clean & ESD compliant configurations. G1 robots lead the industry in footprint to workspace ratios. 225mm G1 robot arms can handle many applications with large working range requirements that other robots need 250mm of reach to handle, thus saving our customers valuable floor space.

Unique to the G1 Mini SCARA robots is that both 3 and 4 axis models are available. The new 3-axis models allow for superior performance for press fit screw tightening and linear dispensing applications. Designed for maximum performance in a small footprint, G1 robots are the most powerful and compact mini SCARAs available in the market today.

Our low cost, high performance Micro PowerDrive RC180 Controller comes standard with EPSON G1 Mini SCARA robots and provides the ultimate experience in ease of use, compact size, and reliability. In addition to all of these great features, the RC180 controller also provides our industry leading EPSON RC+ Controls software and lots of fully integrated options such as: Vision Guidance, .Net support, Profibus, DeviceNet, EtherNet/IP and much more. All this at an incredibly low price! Why choose a low performance solution when you can have a high performance EPSON G1 with Micro PowerDrive Controller?

With the addition of G1 Mini SCARA robots, EPSON now offers 200+ G-Series SCARA robots, ranging from 175mm to 1,000mm in reach and up to 20Kg payloads. EPSON G1 robots are ideally suited for applications and industries which require high precision assembly of small components, demanding cycle times and compact production lines. Chances are that EPSON has the model and configuration you need for your next application since our G-Series lineup now gives customers more power of choice than ever before.

EPSON Robots
www.robots.epson.com

New System Simultaneously Corrects Tool Position for 5-axis Machine Tools

Traditional piecemeal compensation of one axis at a time does not consider axis kinematic relationships and their effect on volumetric accuracy, an ability needed to meet today’s higher cutting accuracy requirements. The multi-axis methodology of volumetric error compensation (VEC) originated in Boeing R&D, St. Louis MO, and uses laser technology from Automated Precision, Inc. (API), Rockville MD.

Executives at MAG recently announced what they claim to be the “industry’s fastest VEC system,” the MAG VEC, which analyzes and corrects positioning errors in all machine-tool axes simultaneously reducing the time needed to determine error compensations from days to hours, and integrating both linear and rotary axes into the tool point compensation process, noted Jim Dallam, MAG’s VEC product manager.

Developed and proven by a government/industrial consortium, multi-axis VEC was developed to improve machining accuracies on large machine tools used to produce today’s large, monolithic and complex-shaped parts. The MAG system received a Defense Manufacturing Excellence Award from the National Center for Advanced Technologies (NCAT) in December 2009. A Boeing official called it a “groundbreaking process” that will dramatically reduce assembly and fitting costs — $100 million a year on large programs like the F-18 or 700 aircraft series.

“It gives you a practical and affordable way to raise a machine’s process capability, typically in less than a day, to meet the tighter accuracies required on new parts and programs in the aerospace industry,” said Dallam. “It’s one thing to hold tight tolerances over short distances along a linear axis, but it’s far more difficult along all arbitrary contours and orientations within a volume encompassing several meters.”

Multi-axis VEC collectively treats all of a machine’s degrees of freedom that affect tool point positioning, unlike conventional calibration methods that sequentially examine machine motion one axis at time. Conventional approaches to volumetric compensation are generally limited to three linear axes and the associated total of 21 potential motion error sources. However, a typical five-axis machine with linear and rotary axes can have 43 potential error sources, not just 21. The multi-axis VEC system compensates for all these.

“Dallam said. “The MAG VEC considers the full interrelated effects from the kinematic stack-up of the machine tool axes. This holistic methodology enables volumetric error compensation for every point orientation and path combination inside the work volume.”

To operate, an NC program positions the Active Target to a cloud of some 200 points representing a series of statistically random multi-axis “poses” within the work envelope. The same NC program is run three times, first with the Active Target at a long tool length, then twice again at a short tool length. The 200 commanded and measured positions from the first two runs are mathematically combined to establish each tool axis vector orientation and the third run gives a measure for repeatability. Automated software processes all pose/point data as simultaneous polynomial equations to determine volumetric compensation based on the kinematic error model of the machine.

The compensation solution is then entered into the control, where “compile cycle” technology integrates the compensations into real-time CNC path control algorithms. The volumetric accuracy compensations work in conjunction with, and on top of, traditional, underlying single axis and cross-axis comps.

Measurements are automated within a single coordinate system using laser tracker technology, a simple metrology tool that does not require extensive training to use. Calibration is performed in just a few hours in a single setup, compared to conventional methods that require multiple setups and several days of time, yet fail to capture volumetric axis interactions.

Boeing, MAG, API and Siemens were members of the industry/government consortium that developed the VEC under the program for Volumetric Accuracy of Large Machine Tools (VALMT). Other participants were the National Center for Manufacturing Science, U.S. Air Force Logistics Center, Naval Foundry and Propeller Center, U.S. Navy Fleet Readiness Center, East, and U.S. Army Anniston Depot. The system was tested and proved out on three large machine tools offering different axis configurations.

MAG
www.mag-ias.com

More on Motor & Drive integration

The motor and drive combination is a basic building block of motion control.  Each component is useless without the other.  So it’s pretty important to come up with a good definition for what the “system” performance needs are to make sure that you end up where you need to be in your design.

Generally, we go to single source suppliers whose motors and controls are designed to operate together.  This approach guarantees minimum performance levels which the supplier can be held accountable for, and that’s a great thing.  But it usually comes with a huge list of features that will not be used in the application, but which you must pay for anyway.

In the industrial user community this is a great benefit because common environmental conditions such as dust, dirt, oil, or washdown conditions are more difficult to deal with and many products are built to these environmental standatds.  No special precautions are needed to make the equipment work.  And the suppliers warranty their equipment for continuous operation at stated speed, torque and environmental conditions.

But as we migrate into other businesses, machinery builders and equipment manufacturers have to apply the same motors and controls in larger numbers, and the overhead costs of motors and controls designed for industrial use become very expensive and make the cost of machinery less competitive.

In the machinery world, much of the electrical components will be built into control cabinets.  So if the packaging is going to be provided, is an enclosed controller somewhat redundant? Or can the motor speed control be integrated into the motor physically to reduce cost?  This is especially attractive if the cost of cabling a single motor can run 10-20% of the total cost of the motor and control.

There are performance elements that need to be considered in the applications as well.  How should the motor behave at zero speed?  What kind of torque regulation is needed?  What is the exact duty cycle of the application (on time versus off time)?   In these areas of motor and control operation the relationship of the motor to the drive is critical.  The drive electronics must have the ability to regulate current going through the motor without casusing overheating.  Some type of sensor on the motor must provide information about the position of the rotor at fairly high resolution, certainly more than every 120 degrees of rotation as with the common Hall effect sensors.

So as much as we may look at the purchase of a motor and controller as a system, there are a lot of nuances involved in the search process for the right hardware for any given application.  And that is probably one of the more difficult parts of doing motion control applications.

Custom Transfer System Adds Value by the Millisecond

Services and products from hydraulics, pneumatics, electrics, and linear technology were linked by Rexroth engineers to produce a custom engineering concept for Swiss company Mikron Machining Technology. “The fact that Rexroth offers coordinated components from pneumatic, hydraulic and electric drive technology right through to high speed control enabled us to select the most suitable characteristics for specific functions,” said Rolf Held, design manager, Mikron. The result was a machine tool that makes real added value out of milliseconds.

In a production environment, fractions of a second count and can accumulate to the extent that they affect cycle times. Automated transfer systems play a key role in many industries, particularly when metal parts must be processed using a number of different machining sequences. Suppliers to the automotive industry, for example, machine a number of items considerably more economically using intelligent transfer units. The machines pick up workpieces in clamping devices and transfer them automatically to the individual machining stations where they are drilled, milled, turned, chamfered or de-burred. Threads are cut and knurled profiles applied. Even peripheral processes such as installation operations or checks can be integrated into these transfer operations. With the transfer concept, all parts can be machined simultaneously.

The Multistep™ XT-200 is setting new standards for transfer systems – especially for the control speeds and the drives used for the various functions. The system makes precision manufacturing possible in non-stop operation. At the same time, the individual stations work practically hand in hand.

Extremely short chip-to-chip times ensure nearly continuous machining, and the system can even be used for high speed cutting. A key advantage is that it combines the productivity of a linear transfer machine with the flexible re-tooling capability of a machining center.

The concept is based on individual interlinked dual spindle modules, which can be used on a stand alone basis, or spread over up to four modules. Five interpolating CNC axes and up to 144 tools machine complex small and medium series parts on five and a half sides without remounting. If the parts are automatically re-mounted in-process, it is possible to machine six sides. The Multistep™ can be adapted to the production volume at any time. In addition, a loading and unloading station can assume the component feed function.

Without a break
While the main advantage of this machine is precision manufacturing almost without a break, further advantages come from the short chip-to-chip time of less than a second and the unusual dynamics. Accelerating the Rexroth CKK linear systems up to 1.4 g to 52 m per minute and spindles with speeds up to 40,000 rpm make for short machining cycles. This is where drive technology from Rexroth comes in: rodless pneumatic cylinders from the BRP Rexmover Series with a diameter of 50 mm and a stroke of 400 mm, as well as a linear axis Type CKK20-145 for strokes of up to 1,100 mm. The maximum force on this axis is around 72 kN in the direction of movement.

“At the end of the day it’s the number of milliseconds that we gain from a number of different points that is the decisive factor,” said Held.

In the standard version, the Multistep™ is fitted with a high-speed CNC Rexroth IndraMotion MTX. Up to 64 axes can be operated in twelve CNC channels independently of one another. The maximum extended version features 54 axes that are required to work in parallel. “Using any other approach would mean that we would need at least two controls and we would have to combine these with each other,” said Held.

The PLC can process 1,000 instructions in 60 ms. At the same time the CNC offers, when controlling eight axes, an interpolation cycle time of 1 ms maximum. The Rexroth IndraDrive servo drives have integrated safety functions for secure hold and safe movement. “Also of interest is the so-called feedback capability, with which the generator capacity of the motors is fed back into the network during the braking operation,” noted Held. Mikron uses the force of hydraulic components for clamping the direct drive B/C axes. The tool clamping mechanisms in the motor spindles that close by means of spring assemblies are opened hydraulically. Here the valve blocks are the same for all spindle variations.

When it comes to workpiece handling in the loading and unloading station as well as workpiece transfer, it is pneumatics that takes care of speed and safety. With the HF03-LG “light generation,” Mikron uses a light and compact variant of the HF valve series. It has a narrow valve width, yet can flow up to 700 standard liters. By using plastic plates, the weight can be reduced even further. The pneumatic and electric controls are located towards the front and arranged in one direction, thus offering increased installation potential, compactness and the possibility of adapting to the space available. By way of an alternative to the traditional multi-pole connection, a field bus connection is used.

From a single source
When it comes to compressed air treatment, Series AS2 maintenance units feature a modular structure. The individual air treatment processes are brought together in maintenance units made from high quality plastic. Filtering, closed-loop control, lubricating and draining – the configuration is geared to user requirements. With the patented oil-fill system, the oil is directly extracted from the storage tank by suction using a hose. This means that the maintenance unit is protected against fouling by oil.

The maintenance units for the pneumatics are located, like the hydraulic power unit and the master control, in a separate control cabinet. The cabinet also houses the central lubrication, power connection and the fire extinguishing system. This arrangement corresponds to the modular structure of the Multistep™ and, by ensuring simple and rapid access to central components, guarantees that the unit is maintenance friendly.

Bosch Rexroth Group
www.boschrexroth-us.com

Motor and Drive Combinations

There is a subtle premise that often escapes us as we talk about motors and the controls that run them.  It is that the motor and controller operate as a package.  In most situations, a customer specification is for input voltage and output torque and speed.  That’s all that is important.  How you get there doesn’t matter a great deal.

But ironically, most motor manufacturers are predominately mechanical engineering centered.  And most drive electronics companies are electronics centered.  And they have very little in common with each other.  Except that their products must work together.  And oftentimes, that’s where the trouble starts.

The drive manufacturer warrants that his drive will produce current and voltage.  But the the motor can have very complex constraints to deal with in response to the excitation of the electronics.  How accurately a 6 step approximation of the sine wave performs, for example, can result in overheating in the motor depending on the loading of the system.  And as the motor winding heats up, the resistance in the motor can change dramatically, especially in the low inductance windings that are common in many specialty motors available today.

Then there are the cabling issues for connecting the motor and drive electronics.  The ac drive industry found out quickly that long wire runs can result in stored energy in the wires themselves.  Standing wave phenomena could cause higher voltages than expected and blow holes in the winding insulation in the motor.

Power semiconductor prices have fallen considerably in the last few years creating situations where it is sometimes cheaper and more reliable to put in parallel devices than to attached single power devices to large heat sinks.  This leads to some serious new options for packaging the electronics.  How about drive circuits in the end bell or junction box attached to the motor?  Actually, some models of the GE ECM motor (now owned by Beloit) are ac fan motors with variable frequency drives and intelligent controls built directly into the motor end bell.  You may have one in your main air handler in the air conditioning system of your home.  I was surprised to find out that I did.

I used to think that thermodynamics of these systems would be impossible to manage.  But the fact is that the drive efficiencies are getting really good.  One team I worked with was producing a 500 Watt brush drive that only shed about 20 Watts of loss at full load.  That’s some incredible efficiency.  So the notion of integrating motors and drive electronics is much more reasonable than it used to be.  And there are stepping motor packages that have been doing it for years.

So where is this all heading?

The fact is that the motor and drive electronics must work together as a package.  There is an increasing need, and an opportunity to create further performance enhancements, by the two technologies working more closely together.  More innovation will lead to better energy efficiency and new design opportunities and a chance to recharge (pun intended) an industry that has been losing share to offshore competition in the last few years.

New Motion Feedback

The field of motion control is heavily dependent on the feedback device.  There are a world of issues encompassed in this statement.  But I will skip the majority of them and jump to the conclusion that magnetic encoder technology has long been a favorite of mine as a potentially ideal solution for a number of reasons.  Magnetic position technology tends to be more resistant to environmental problems such as temperature, dust, dirt and humidity.  Since all motors are heat producing systems, temperature restrictions for feedback technology can be a problem.  And since electric motors are frequently found in environments where there is dust, dirt and humidity, magnetic feedback would be ideal.

On the other hand, magnetic feedback has been complex and expensive in the past.  Resolvers require high precision windings in the sensor and precision power supplies to excite them.  Can you spell “expensive”?

Enter the Hall sensor.  In spite of the fact that the Hall Effect has been understood since 1879, the use of the technology has only recently become widespread with the fabrication of semiconductor level Hall devices.  The Hall sensor as a transistor found very popular application in sensing the three phases of brushless dc motors’ permanent magnet rotor.  The bldc motor technology was essentially impossible without this crucial piece of technology because in the early versions of the control, it was impossible to start the motor without knowing which phase to energize.  This has been less of a problem with the advent of low cost, high performance microprocessor controls that are able to run brushless dc motors with or without Hall sensors.

New arrangements of the Hall devices into arrays with greater capabilities is where the Hall effect technology intersects the position feedback technology.  The Hall arrays are capable of sensing small permanent magnet domains on rings that permit rotorary position to be sensed in either analog or digital form.

While there are a number of suppliers of Hall sensing arrays for motion control, a couple of new twists have been added.  The Timken company has added some new features to the Hall array that have additional benefits.  Among them are the ability to program the numerical value of the digital output, which can be a very helpful feature that eliminates fractional remainders and rollover error in control systems.

In addition, Timken is introducing a new linear version of the technology which is a real first for the motion community.  Most linear motion is the result of converting the rotary motion through a linear mechanical device, either a belt or leadscrew.  But the control system is measuring the position from the feedback  on the motor that’s driving the system and not on the load.  So the mechanical error of the leadscrew or belt is the limiting factor in high performance linear.

And to make the new magnetic feedback really interesting, it is comparable in cost to conventional optical encoders.  Which is really going to create some new opportunities for everyone in the motion control field.

Magnetics 2010 and Motion, Drive & Automation

There is a small industry conference that takes place every year with a lineup of industry experts that is top notch by any standard.  It’s called the Motion, Drive and Automation Conference put on by E-Drive magazine.  This year it is located at the Disney Hilton Resort in Orlando and is taking place on January 28 & 29.   The conference includes a wide range of industry experts from many fields of advanced electric motor design, advanced motor control concepts, power semiconductors and state of the art motor testing system.  There will be a lot of technical and product presentations that showcase leading edge technology in electric motors, precision gear reducers, new technology for motion sensing, and a number of improved power semiconductor devices for the motor control industry.  This is a great place to get up to date on the latest technology that will impact of motor and control technology across many industries over the next few years.

In addition, the Magnetics 2010 Conference will be running concurrently at the same venue.  Magnets are a strategic material without which many motors would simply not operate.  In the ever-changing motor industry, there is always a new design that seeks to make an enhancement over previous solutions, or introduce a new solution to old problems.  Declining prices for Neodymium Iron Boron magnets over the last few years have created a number of novel design shifts which have been instrumental in bringing more varieties of permanent magnet machines into the forefront of motion control and mechatronic technology.  To the point where over the last two years a resurgance of permanent magnet rotor designs have been created to improve the energy denisty and lower the cost of specialty motors in washing machines and air conditioning compressors.

This last development, combined with the forecast increase of hybrid electric car sales coming this year, are expected to increase the sale of permanent magnets by 10-15 percent by 2011.  That’s a staggering jump in a market that is almost exclusively supplied by China.  And there is no assurance that China can meet the forecast production.

The US Department of Commerce usually has a say in the sale of products or businesses to foreign countries that are deemed to be strategic or sensitive technology.  In fact, I got stuck in a situation where my employer was told specifically that we could not sell a CNC controller to a Korean customer.  That’s pretty small potatoes compared to controlling the supply of permanent magnets which influences billions of dollars worth of electric motors manufactured and sold all over the world.  So it strikes me as a little odd that the sale of Magnequench to its current owners, Neo Materials, was completed without a much discussion. leaving the US without a domestic magnet supplier.

There will surely be a lot of discussion about this situation at the conference, and I will be in attendance to get the latest information on the subject.  So look forward to a review of the conference in an upcoming post.

Magnets aren’t US anymore

The permanent magnetic is a quiet, unobtrusive work horse in so many applications that it, like many things that are mechatronics related, is mind bogglingly (is that a word?) pervasive.  Magnets are the key material technology to enable high efficiency and power dense electric motors.  And electric motors are everywhere.

The particular magentic material that has enabled the CD, DVD, Hard Disk Drive, high performance speakers, magnetic resonance imaging and many other technical wonders, is Neodymium Iron Boron.  Based on General Motors research on magnet materials (in the 1980’s), scientists found a particular molecule of these materials which exhibited extremely high magnetic strength.  And, of course, one of the immediate benefits would be reducing the size of starter motors in cars by 30% and the weight of the motors by even more.  Great stuff!

But making the molecule wasn’t exactly a picnic.  Alloying was easy, but it turned out you had to cool the material down suddenly in order to get just the right molecule to form in a powder and then sinter and magnetize the result.  A whole new process had to be developed, called spin casting, to cool the material quickly enough to generate high quality raw material for NeFeB magnets.   I’m sure there are a lot more technical details, but I don’t remember much from my tour of the GM Magnequench facility in Indiana.  It’s been several years.

NeFeB alloy has been dramatically improved and as demand has increased, fortunately, the price has dropped from the extremely high levels during it’s introduction.  As prices have declined it is estimated that 16,571 tons of Neodymium were used in magnet making in 2009 and 24,635 tons will be used by the year 2014.  That’s an increase of 48% in five years.  That’s huge.

The reason for all the increase is the fact that NeFeB magnets make really efficient motors.  So the new generation of appliance motors and air conditioning compressort that include NeFeB magnetics to increase the flux of the rotor combined with electric and hybrid car motors are driving demand more more magnets.  And now some emerging technology in the wind power marketplace, direct drive generators, will require many tons of additional material.

But what about our friends at GM Magnequench?  They’re gone!  The great future, full of potential for a US manufacturing company, lost to the sale of the company and closing the manufacturing facility.  GM sold the company to New Materials Technology in Toronto which is owned by China.  But the new owners couldn’t run the US factory at a profit.  Even at $20/hour for labor.  All the manufacturing jobs, gone.

There is currently no NeFeB magnet manufacturing in the US.  Which is kind of crazy when you think of all the applications we have for the stuff.  Even worse is the fact that a lot of advanced military hardware is dependent upon the magnets for guidance motors on missiles and a host of other applications.  And according to one source China now owns 97% of the world’s Rare Earth Elements sources.    Which is why there are now hundreds of companies in China selling magnets.

On the positive side, this has lead to overall declining prices for these magnets.  But will that continue to be the case?  The Chinese government is expecting to decrease their exports of magnets by 34% next year.  This could spell trouble for many companies.

But there is hope. The USGS has reported that the Mountain Pass Mine in Southern California is one of the largest and richest deposits of Rare Earths, including Neodymium, in the world.  And Molycorp is ramping up to fill the gap with new mining and manufacturing capacity.  Go get ‘em guys! Free enterprise at work.

Motion and Software

Rockwell Automation recently had it’s Automation Fair during which a number of new product announcement were made.  The company has announced a collaboration with Dassault Software Systems to create a suite of tools that deal with various applications of industrial automation and manufacturing on the plant floor.  Of particular interest to the mechatronics world is coordination between Solidworks modeling software and Rockwell’s Motion Analyzer.  In addition, Rockwell has made an important ease-of-use connection between the Motion Analyzer which has traditionally been used for sizing motors, and the control system software.

As an experienced user of early version of the Motion Analyzer, I used the software as a tool to analyze tradeoffs between time, torque and inertia to optimize customer machinery and processes in motion control applications.  Good motion control starts with good mechanical design, and there are so many variables and tradeoffs, that it’s often difficult to navigate your way to the best solution.  A good motion analysis tool automates the process so that you can examine an axis requirement and explore several options for how the axis can be optimized.

The results of the Motion Analyzer can be directly integrated into the PLC editor RSLogix.  This is usually an area where there is a major duplication of effort, since everything that you have to program in the control system is data that you have worked with in the Motion Analyzer.  So kudos to the Rockwell team for getting this feature added to the RSLogix suite.

The Motion Analyzer uses information about the Rockwell Automation motors and amplifiers to match inertias to loads and duty cycle requirements to the thermal capability of the equipment.  This is an often overlooked subltety of the equipment, but at the end of the day, it’s all about the amount of heat you can get rid of.  And the duty cycle contains all the critical information about how much energy you need, when you need it, and how long you have to dissipate it.  In addition, I have found that everyone’s idea of thermal modeling is different.  So it pays to do the simulation work at the front end of the design.

But, we always used to joke that we were doing solid modeling anyway.  Everything was a cylindrical object of a certain diameter, length, material density, etc.  So it stands to reason that integration with a 3D modeling system would make sense.  After all, a little step up in capability could lead to a lot better design work from the start. And the ability to link mechanical design at the earliest part of the design cycle, directly to the output at the motor and control system, makes for better outcomes every time.

Big Wind Machines

Recently I had occaision to discuss the merits of wind power with a colleague.  In particular there is a controversy between horizontal axis wind turbines, the giant propeller driven systems you see in advertisements, and vertical wind, which does not have much presence in the marketplace.  The premise is that horizontal systems can take advantage of the large swept area of the propeller blades to generate a great deal of force.  I’m not sure if this is supposed to imply that large swept areas intrinsically convert more kinetic energy from the wind into electricity.  And it is easy to conclude that this is the benefit of horizontal wind turbines.

Except that there is a fundamental mechatronic system at work.  The large propeller turns at low speeds, typically around 18 rpm on average, and there is a massive gearbox that is used to increase the speed of the output to turn a generator at high speed, which is typically where generators are most efficient.  The gear increaser has the effect of also increasing the amount of torque required at the input (propeller) by the gear ratio.  So if the gear increase is 100:1, then the propeller must be size 100 times larger in swept area in order to produce the needed torque to turn the generator.

This actually gets a bit worse since the mass, and it is very substantial, of the gear box itself represnts inertia that is resisting the turning of the blades.  And there is a generator rotor at the end of the gearbox whose mass (massive mass) is now resisting the turning of the propeller by the square of the ratio.  So if the ratio is 100:1, the inertia is increased by 10,000 times.  Even magnetic drag, or the residual attraction of the rotor to the stator, will get amplified in the same fashion, making it a significant force to contend with.

Add to this situaion a list of systems losses for overall fricitional loss of the bearings and gearbox, parasitic losses for steering and blade pitch adjustments.   Efficiency losses due to long distance transmission of power, that is a by-product of the remote sites that have favorable wind conditions.  It’s a pretty difficult situation to engineer.  And they keep proposing to build them bigger and bigger, hoping that the scale effect will overcome the problems.

All of the vertical wind systems I have seen so far are much smaller due to the fact that smaller rotors can turn at higher speed and power electric generators directly.  The flax axial generator is very popular in do-it-yourself designs that people are experimenting with in their back yards.

But vertical wind can also scale up.  And there are a few companies doing it.  With convertional wind power costing $2/watt, vertical systems could bring that price down very quickly and allow systems that can be installed close to the point of use or in offshore arrays where generation takes place almost 100% of the time.  Unlike the average 31% on the large land based systems.

Now that’s progress, 300% increase in energy generation at lower cost.  Hope it comes to market soon.

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