ALIO Industries resides in a unique place in the world of motion control as the only supplier that can claim true nanometer-level repeatable precision. Working at the cutting edge of innovation in motion control solutions, the company sees its role as being more educational than promotional. The advances that ALIO Industries make open up new and exciting possibilities for industry, and much of the company’s time is spent reaching out to manufacturers to demonstrate the unparalleled levels of precision that its solutions can attain. Once this has been achieved, OEMs are able to conceive of applications that would otherwise be deemed impossible. In this article, Chris Young catches up with Bill Hennessey, Founder and CEO and Walter Silvesky, VP Sales, at ALIO to discuss the state of today’s market for motion control solutions.
Chris Young, MD, Micro PRM Ltd
Q. Could you briefly explain what makes ALIO Industries tick?
BH. Well, we have been operating in the motion control sector for nearly 20 years now. We have a passion to build nanometer-level precision motion systems that others say cannot be produced. We are an extremely competitive company, always pushing to exceed even unthinkable specifications. We have always focused on performance and quality of our systems, and we test all components before they are integrated with any ALIO product, choosing only the highest quality and highest performance components regardless of cost.
Q. Ultra-precision suggests ALIO provides solutions for exacting applications?
BH. We do yes. Ultra-precision for ALIO means nanometer-level motion control, but we typically tend to steer clear of non-specific claims of precision or accuracy, as it is because of these that sub-optimal motion control solutions are sourced by customers that have been confused by terminology. To make it clear, when sourcing motion control solutions, customers need to attain the level of precision required not just once, but repeatably. This is often the key to obfuscation for motion control solutions providers. Claims will be made about the level of precision that can be achieved once in the most favourable and least taxing of situations. But these bear little or no resemblance to the levels of precision that can be achieved under demanding circumstances again, again, and again. At ALIO we provide nanometer-level precision motion control solutions that provide this nanometer-level precision repeatably, and because of this we are in a unique position.
Q. I hear some frustration about this lack of clarity?
BH. Absolutely, and for two reasons really. First, there is the understandable frustration as an innovator company that the unique developments that we have made are claimed to have been matched by alternative suppliers when this is just not the case. But second — and much more importantly — is the fact that false claims as to the precision, reliability, and repeatability of motion control systems will see OEMs making often substantial and strategic investments in technologies that flatter to deceive and produce sub-optimal results. This is not good for anyone. It tarnishes the reputation of the motion control sector, it causes OEMs to question and potentially shelve projects as they perceive that the motion control that they require cannot be achieved. This is the worst of all worlds.
Q. Walter, from your perspective what are we dealing with here?
WS. Bill is right, there is a lot of confusion out there as to the precision that can be repeatably attained through motion control solutions available on the market today, and that confusion is in many instances fomented by motion control technology providers themselves. You see, when discussing precision and accuracy, when it comes to motion control there are too many variables that are not fully understood by customers, and which technology suppliers are fully aware of and swerve in their marketing and communications, using data that often deceives completely. In many ways, the most accurate end of the motion control market is quite a confusing place to be, as the handful of extremely accurate motion systems suppliers tend to use non-consistent and often illusory ways of describing the levels of precision that they can attain. ALIO has always worked in the area of nanometer-level motion control, and as such has a unique perspective on what really works when looking for this level of precision. Because of this, and with our Hybrid Hexapod® solutions very much front and center, we have focussed on educating the customer base to navigate alternative solutions, and give them the tools to interrogate solutions providers in such a way that they can secure a motion control technology suited to their specific applications. The Hybrid Hexapod® has been a game changer for enabling new and novel processes.
Q. Can you explain why you claim that the Hybrid Hexapod is such a potential game changer?
WS. I would qualify your use of the phrase “potential game changer”. I have been working in the motion control sector with various companies for many years, and I can tell you that from my perspective — and from the perspective of a growing array of end-users — the Hybrid Hexapod “is” a real game changer. The Hybrid Hexapod® was developed by ALIO to address the critical weaknesses of conventional legacy hexapod designs, as well as the weaknesses of stacked serial stages, and to achieve nanometer -level accuracy, repeatability, and high-integrity flatness and straightness during motion. It utilizes a tripod parallel kinematics structure to deliver Z plane and tip/tilt motion, integrated with a monolithic serial kinematic structure for XY motion. A rotary stage integrated into the top of the tripod (or underneath it depending on application needs) provides 360-degree continuous yaw rotation. In this hybrid design, individual axes can be customized to provide travel ranges from millimeters to over one meter, while maintaining nanometer-levels of precision. Engineers working at the cutting edge of what is possible must be stimulated to ask more as they see that this technology reaches places others cannot, has the potential to promote innovations, and can optimise efficiency and cost-effectiveness in manufacture. The Hybrid Hexapod® is orders of magnitude more precise than traditional hexapods, being 100 x stiffer, 30 x faster, and with 10 x the usable work envelope of industry standard options.
BH. Coming back to the issues of false or illusory claims of precision, reviewing traditional legacy hexapods alongside the Hybrid Hexapod® makes this abundantly clear. At ALIO, we believe that any claim of precision or accuracy must be first meaningful, and second provable. When looking at motion control solutions such as the Hybrid Hexapod®, this is vital, as in common with all hexapods it is a motion control technology that operates with 6 degrees of freedom (DOF), and operates in 3-dimensional space. Because of this the conversation needs to move toward volumetric accuracy. Despite this, all 6-DOF motion control solutions suppliers are characterised by performance data of a single degree of freedom. This practice leaves error sources unaccounted for in several degrees of freedom, especially in the areas of flatness and straightness, which are critical precision needs at the nanometer-level. The traditional hexapod’s best flatness and straightness of travel is still no more precise than in the order of magnitude of tens of microns per axis. Because hexapods have six independently controlled links joined together moving a common platform, the motion error of the platform will be a function of the errors of ALL links and joints. Hexapods are known to have optimum accuracy and repeatability when performing Z-axis moves, because all links perform the same motion at the same relative link angle. However, when any other X, Y, pitch, yaw or roll motion is commanded, accuracy and geometric path performance of the hexapod degrades substantially because all links are performing different motions. It is generally accepted that hexapods have relatively good stiffness compared to serial stacked multi-axis systems. However, it is often only the hexapod’s “Z” (vertical) stiffness that is considered. Geometric design stiffness has a critical impact on a hexapod’s platform repeatability and rigidity. A lack of design stiffness relates directly to a weak XY plane stiffness with the conventional hexapod working platform. Moreover, this inherent design flaw of the conventional hexapod negatively affects XY axis performance, especially with thermal bonding or machining applications that require more force to be performed accurately within the XY plane.
WS. And the nub of all this is that traditional hexapod providers are aware of these issues, but instead of confronting them, mask the inefficiencies inherent in the system by throwing meaningless precision claims at the situation or not drawing attention to them at all. One for example makes accuracy claims that seem really good, but are in fact impossible to achieve on any 6-link architecture, and above all would be totally out of reach of any customer. The reason for this is that the precision specs that they quote only apply to single axis moves from the center / mid-stroke default position. Who would ever buy a 6 DOF hexapod to only use it one axis at a time at its center of travel? The accuracy as you move to different positions and angles has to degrade probably by multiples of 5 x to 10 x.
Q. So how do you prove the precision that the Hybrid Hexapod can attain?
WS. The Hybrid Hexapod® is redefining the area of precision motion control, and the rule book is having to be rewritten to accommodate it and to position it correctly against industry alternatives. The level of precision achievable with the Hybrid Hexapod® renders the vague and illusory industry standard claims of micron and sub-micron precision redundant, and has forced industry to move towards the concept of Point Precision®. Point Precision® includes all 6 DOF of errors of each axis in motion, guaranteeing the precision point in the full work envelop, and allows for a “precision number” to be quoted based on an exact point on the wall (as if you used a laser pointer) whereas today’s standard only gives the measurement to the wall as if using a flood light. As a signifier of accuracy and precision today, Point Precision® truly is a must for many applications from laser processing to metrology. Beyond the Hybrid Hexapod, another key product that ALIO has developed after years of evolution of its True Nano® single axis stages, is the monolithic XY stage product family with extreme 6-D Nano Precision®. The ALIO monolithic XY stages, (with enclosed center and open center), outperform all alternative XY motion solutions, and also use Point Precision® motion performance and offer unrivalled stiffness.
Q. There are instances presumably when customers will not require or cannot justify the expense of nanometer-level precision motion control solutions. How has ALIO responded to this demand?
BH. Well, we also offer a newly introduced µII (micron II) product line, to compete in the lower cost, lower precision micron (µm) world. Demands for low cost, mid-precision, reliable long travel stages influenced ALIO’s decision to introduce the µII product line. As with all ALIO products, this line was designed using ALIO’s uncompromising standards of “quality first” thus providing the customer with long term reliable operation. The easily configurable µII product line stages can be used as a single axis, stacked in XY orientations, or complete gantry operation. ALIO’s control platforms are easily set up to handle the complex motion requirements for rigid gantry motion. The µII recirculating ball rail bearing stage line comes standard in sizes of 100mm up to 1 meter thus providing the end user a solution suitable for many applications.
About ALIO Industries
In 2001, Bill Hennessey launched ALIO Industries by introducing the first nano-precision hexapod and tripod robots. Since then, the Arvada, Colorado, USA-based company has been an innovator in nano technology motions systems. The company’s products include hexapod robotic systems, air bearing systems, linear and rotary nano-precision systems with both mechanical and air bearings guides. It also provides systems in atmospheric, clean room, and ultra-high vacuum environments, all with nano positioning.
Chris Young is the Managing Director of Micro PRM Ltd, a media and communications agency specialising in the precision and micro manufacturing sector