Linear Motion - 3/27 - Motion Control Tips

Embedded actuator synchronization offers stability, efficiency for large loads

August 11, 2017 By Paul Heney Leave a Comment

Thomson Industries Inc. has announced availability of new synchronization capabilities for its Electrak HD heavy duty electromechanical linear actuators. Designers of equipment in which large or awkward loads must be moved repeatedly and evenly, such as large solar panels or heavy hoods on construction equipment, can now simultaneously distribute that load using up to four actuators.

The Thomson Electrak HD, which boasts the most advanced onboard controls of any actuator in its class, has added a synchronization option to its feature set.

Traditional methods for synchronizing multiple actuators can be inflexible. Gas spring technology, for example, is limited in application, while hydraulic cylinders can be prone to leakage and costly to maintain. Non-integrated electronic systems have more flexibility and are cleaner but require external devices such as encoders and potentiometers to track position and send feedback to an external PLC or other logic solver.

“The ability to synchronize movement of large and potentially awkward loads is something our customers have been requesting as they seek to automate larger applications or improve ergonomics,” said Chad Carlberg, Product Line Manager for Industrial Actuators at Thomson. “We are pleased to announce that we have tapped into the advanced electronics capabilities of our popular Electrak HD heavy duty linear actuator technology to achieve synchronization more easily and cost effectively than is possible with any other available approach.”

Synchronization enables motion integration of up to four Electrak HD actuators. When multiple units with the synchronization option are installed, designers can take advantage of a more stable and potentially quicker lift, no additional guides, and improved handling of uneven loads.

Thomson achieves its synchronization by embedding all load handling technology into a single electromechanical actuator, which is then wired in sequence with up to three other similarly equipped actuators. Designers install these wherever linear movement is needed without the need for external assemblies. Once the actuators are installed, customers synchronize them instantly by wiring them together and operating a single unit with a simple switch. During operation, system electronics detect speed changes that indicate load imbalances, thereby eliminating bouncing or other effects of imbalance.

By using multiple actuators, synchronization increases system movement speed more efficiently. A larger load that might normally use a single, heavy load actuator, for example, could be moved faster by combining multiple, lower load actuators. Synchronization also retains all Electrak HD mechanical capabilities, including the handling of bidirectional loads of up to 10 kN (2250 lbf) with stroke lengths up to 1000 mm (39 in.) and accuracy of 1% of stroke from 100-1000 mm. High-quality ball screw assemblies provide efficient current draw and support speed options up to 43.5 mm/sec (1.7 in./sec) (using the 1.7 kN [382 lbf] version).

Applications
There are numerous opportunities to apply the benefits of synchronization. In addition to solar panels and off-highway agricultural equipment mentioned earlier, potential applications include:
• Industrial logistics trains for automatic correction of imbalances between the front and backend loads, which can cause stoppage, noise or unnecessary wear.
• Doors on ovens and large processing equipment for smoother, safer opening and closing.
• Ergonomic patient-handling equipment such as lift tables, synchronizing operation of lift columns for smoother movement and higher-quality patient experience.
• Marine applications, such as rudder assemblies, for smoother, more responsive steering.
• Structural engineering applications such as automatic loading doors in factories and warehouses.

Availability
Electrak HD linear actuators with synchronization capability are available immediately. The same actuator can function as a master or slave in any multiple-unit configuration, simplifying replacement and reducing spares requirements.

Thomson Industries Inc.
www.thomsonlinear.com.

Moticont adds servo actuator to SDLM Series

July 28, 2017 By Paul Heney Leave a Comment

The new SDLM-019-070-01-01 direct drive linear motor is the latest addition to the series of zero backlash, zero cogging, high acceleration, high speed, high resolution, long life linear servo motors from Moticont. Also known as an electric cylinder, this compact direct drive linear motor is just 0.75 in. (19.1 mm) in diameter and 2.75 in (69.9 mm) long. Protected inside the motor housing, the linear optical quadrature encoder is directly connected to the shaft for the greatest possible accuracy. This direct drive linear motor features 1.25 µm (0.000049 in.) in of resolution.

The SDLM-019-070-01-01 direct drive linear motor has a stroke length of 0.500 in. (12.7 mm) and a continuous force rating of 9.7 oz. (2.7 N) and peak force of 30.7 oz (8.5 N). This non-commutated direct drive servo motor features: Quiet long life plain linear bearings, an integrated internal (1.25 micron resolution) quadrature optical encoder with differential outputs, and a non-rotating shaft. Some applications include: Manufacturing (assembly and inspection equipment), sorting and packaging, semiconductor handling, medical equipment and instruments, antenna positioning, dampers and valve actuators.

Direct coupling of the load or stage to the low inertia non-rotating shaft eliminates backlash and allows for high acceleration/deceleration. Both ends of the motor and shaft ends have threaded mounting holes for easy integration into new and existing applications. The SDLM-019-070-01-01 Direct Drive Linear Actuator is also available as a complete plug-and-play linear motion system with a matching motion controller.

Moticont
www.moticont.com

Thomson Industries collaborates with research team to develop new Tesla Coil Designs

June 7, 2017 By Paul Heney Leave a Comment

Thomson FSI Style Metric Precision Ball Screw.

Thomson Industries, a leading manufacturer of mechanical motion control solutions, has donated a high-precision ball screw assembly to The Geek Group National Science Institute in Grand Rapids, Michigan, to help develop revolutionary designs of Tesla Coils (TC). An ambitious R&D program has been initiated there to discover new uses for the TC with help from a new automated process for winding coils.

Thomson was selected because of their top-notch application engineering support and breadth of product offerings, which enabled delivery of an optimal complete ball screw assembly. That Thomson ball screw assembly will help The Geek Group’s high-energy engineering team convert from typical manual winding to a much faster, more accurate automated process for winding thousands of coils required to conduct their experiments.

A Thomson customer support engineer guided The Geek Group engineering team in selecting the exact configuration to best match their needs. The product selected was a quick-install ball screw assembly that avoids any precision problems that may result from assembling components on site. The final configuration consisted of a Thomson FSI Style ball nut along with an eight-foot-long ball screw just under an inch in diameter.

“We set our IRC team on the task of finding the best linear motion technology in the industry,” said Chris Boden, CEO of The Geek Group. “The team, composed of a couple hundred experts from many science and technology disciplines, analyzed about a dozen different products and concluded that only the Thomson drive could do exactly what we needed and exactly how we wanted to do it”.

The TC production program has already begun, and The Geek Group has plans for experimenting with larger coils in the future.

Thomson Industries Inc.
www.thomsonlinear.com

Electric actuator trends Part 2 – new applications, IoT, online tools

May 11, 2017 By Miles Budimir Leave a Comment

This is Part 2 of a two-part series. You can read the first part here.

Tell us about a new application where engineers used your motion-control and power-transmission components to improve their design. What about this application is unlike anything possible 10 years ago?

Tom Quartararo
Ultra Motion

Another industry trend that has been steadily developing is the replacement of pneumatic actuators with electromechanical actuators. Many machine designers are looking for the controllability, repeatability, and efficiency of electromechanical actuators, with the speed and reliability of pneumatic actuators. In order to address these demands, the Servo Cylinder was developed as a brushless dc actuator with top speeds in excess of 14 in./sec, high acceleration capability, and oversized mechanical components. A successful mode of operation in pneumatic replacement is four preset position mode, where the state of two optically isolated digital inputs corresponds to configurable absolute positions. In many cases this mode allows for drop-in pneumatic replacement with existing control systems, and provides controlled speeds, controlled accelerations, and position repeatability better than 0.001 in. Higher speed Servo Cylinders are currently in development so that more machine designers can realize the benefits of electromechanical actuators in their pneumatic applications.

Aaron Dietrich
Director of Marketing
Tolomatic

The oil and gas industry has always used hydraulics to automate its valves used in critical applications due to higher forces, longer life and hazardous location requirements. This industry is also very risk-averse and very, very slow to change or adopt new technologies. Now using servo actuator technology, these customers are able to achieve speed and force performance they never thought was possible.

Ben Lutz
LinMot

Our big breakthrough is direct drive linear motion, removing the inefficiencies and imprecision of air without the loss of dynamic movement. For an application like basic part rejection or diversion, rotary to linear systems are too slow, flat linear motors too bulky, and voice coils are too small. The LinMot motor can help OEMs and end users remove air from machines with very little redesign.

One of our second successes is in the capping industry. Previous technology would require a new cam or tooling to be cut for a change in packaging types. Even a small change between package heights would still require the installation of a new cam or fixturing. Our standard linear rotary motor makes changeover between products a matter of changing dimensions from an HMI. Changing form factors with our motors is now the work of a programmer to create a new recipe and test the same day.

Jared Zammuto
Sr. Design Engineer
Warner Linear

We recognized a growing demand for power-dense actuators used in a variety of off-highway and other extreme-duty applications including agricultural sprayers, snow plows, and mower decks. In response, our engineering team developed a completely new, compact electric actuator with self-contained hydraulic actuation that provides the performance of hydraulics without the space requirements and expense of a full-size hydraulic system. With minimal initial drift, once seated, the new, patented H-Track actuator is immune to vibrational drifting and hydraulically self-locks during load reversals, while holding its position without power. This is especially important in applications such as mower deck lifts, agricultural sprayer booms and snow plow blades where the moment force acting on the actuators is dramatically increased due to the constant bouncing that occurs during operation. The actuators unique fluid design allows the unit to withstand sudden impacts, such as hidden concrete parking blocks in a snow plow’s path, without damage to the actuator. These types of encounters can quickly destroy most electric actuators.

The new patented H-Track actuator from Warner Linear is an electric actuator with self-contained hydraulic actuation that provides the performance of hydraulics without the space requirements and expense of a full-size hydraulic system.

David Basken
Misumi

The use of highly engineered coatings in fixture components is rapidly changing. MISUMI introduced a new RDLC coating for locating pins in aluminum body panel assemblies for Body-in-White applications. They eliminated the build-up of the soft aluminum material on locating pins and the fixture-locking
it created.

What kinds of large-scale industry moves are you seeing to miniaturization, System- on-Chip (SoC) technologies, automation, (in the case of electric-motor-driven motion designs) efficiency and customization?

Ben Lutz
LinMot

Almost all servomotors now have plug-and-play technology so when they are connected to a drive their motor characteristics and parameters are preloaded for operation. Many servos use auto tuning that provides general parameters and if you will ‘good enough’ application tuning. Integrated motor/drive designs are still being introduced and are becoming more accepted especially for existing installations where electrical cabinet retrofits are not easy to do and perhaps impossible. LinMot addresses the market with direct drive motor technology to provide the most efficient and most productive method for point-to-point motion thus providing a simple machine design. The linear-rotary motor technology eliminates many mechanical components and allows for a much simpler machine design.

Where do you see the Internet of Things, IIoT, Industry 4.0, or Connected Industry changing motion system design? Where do you see new materials changing motion design?

Aaron Dietrich
Director of Marketing
Tolomatic

This is everywhere and will soon be in all things. All components in the motion system will be connected to the internet of things in the near future, providing more information about what is happening with the motion or the factory, such as diagnostic information on when components need maintenance or failure notices. The sky is really the limit with the low cost DSPs being able to be connected easily to the internet using industrial Ethernet protocols.

Tolomatic hygienic electric actuators are approved by 3A and USDA for food and beverage applications such as pressing, pumping, cutting or slicing.

Ben Lutz
LinMot

We see remote access for the Internet of Things (separate IP addresses) so that every axis is connected through the plant network increasing uptime and allowing remote access. Monitoring data from the drive allows users to directly predict maintenance intervals by the increase in average current and more accurately
report errors.

Additive manufacturing was used for our USB-Serial converter based on the needs of small batch solution to solve customer’s integration requests from a single tested source.

The newest lubricants have high temperature stability and provide for a wide operating range. All the lubricants LinMot uses are food grade – a big plus to be able to use in and around consumable goods.

Where do you see online configuration tools changing how design engineers specify and buy components? How is your company using software and new forms of connectivity to drive innovation in motion design?

Aaron Dietrich
Director of Marketing
Tolomatic

I feel it’s already there. If you do not have a good online presence and good online tools, customers do not want to do business with you. Online CAD configuration, sizing and selection tools, educational content, e-commerce, and other tools are a must for suppliers to stay current.

Tolomatic’s integrated linear servo actuator, a heavy duty actuator with a compact footprint, simplifies mechanical design and can replace pneumatic and hydraulic systems.

Ben Lutz
LinMot

LinMot Designer is also freely available so that any potential user can size their application and directly calculate energy savings. The LinMot website features all the installation guides and CAD models so that parts pass easily from concept to combination. Finally, LinMot Talk configuration software is free online allowing potential users to learn through examples or access existing hardware.

Christopher Morris
Misumi

Not surprisingly, quality, cost, and lead time are crucial elements as engineers begin sourcing a component supplier. A piece often overlooked is the ease of obtaining CAD models. One of the least exciting aspects of mechanical design is researching and procuring CAD files for purchased components. Many times this involves browsing several vendors’ sites, downloading, importing, and constraining CAD files. This is a process that is commonly repeated multiple times through each design revision.

MISUMI has been working extensively on a free CAD add-on suite dubbed Rapid Design. The first of five applications, inCAD Components, allows users to manipulate MISUMI’s configurable components, research pricing, and access technical information – without going to the website. Independent testing has found this tool to reduce the typical design phase by 32%.

You can read Part 1 of the series here.

Electric actuator trends Part 1 – more integration

May 9, 2017 By Miles Budimir Leave a Comment

If there is one overarching trend for electric actuators, it has to be integration. That is, integrating more components such as feedback devices, controllers and drives, and functions into the actuator itself. Designers are looking for reliable actuators that can be quickly and easily installed, powered up and operational.

Here’s what some top actuator manufacturers told us about the trends they’re seeing in the industry.

Do you see the same or more demand for motion designs offering design simplicity or turnkey operation? If you see more demand, what kinds of pre-engineered solutions are you offering to satisfy this change in the marketplace?

Tom Quartararo
Ultra Motion

We’ve seen a steady increase in requests for turnkey actuator solutions that are robust, reliable and easy to use. The ideal actuator solution in many applications is one that will interface directly with existing PLCs, have flexible communication protocols for future system augmentation, and not require extensive learning curves or actuator specific expertise. In a market dominated by smart motors, we saw a need for a “smart actuator” that had built-in absolute position feedback and control electronics designed specifically for electromechanical actuation and ease of integration. This theme is what drove the development of our Servo Cylinder, which integrates our proprietary Phase Index absolute position feedback with a high performance brushless dc controller and robust mechanical components.

Aaron Dietrich
Director of Marketing
Tolomatic

Yes, motion systems can be complex, with many moving parts and the combination of many different product technologies. The more suppliers can combine products and technologies into solutions to simplify the usage and deployment, the better it is for the end-user. Tolomatic does several things to help customers with design simplicity. Examples include easy solutions such as mounting a motor on an actuator. Tolomatic’s online “Your Motor Here” program is a large database of most brands of servomotors. Once the specifier selects a motor, Tolomatic provides motor mount, coupler, belt/pulleys, and mounting hardware. Another example are Tolomatic’s integrated servomotor actuators that are integrated into any feedback device and mimic any servomotor connector such that standard cables can be used from the drive manufacturer. Further integration involves the servomotor and drive into the actuator that eases setup, configuration, tuning and deployment because the drive/controller already knows everything about the actuator.

Ben Lutz
LinMot

In the U.S., we see a strong demand for design simplicity, our pre-guided axes like the P04 and F-Guide feature an extrusion profile and integrated guide rail allowing customers to directly mount loads without stumbling over alignment. The F-Guide system allows for a bolt together gantry from stock parts, making 3 or 4 axes of motion possible with no teach-pendant.

Our customers have also shown preference for control systems that require minimal drive intelligence and communication setup. PVA and NC streaming both allow axis control to stay within the PLC for tighter machine synchronization and a familiar programming environment.

David Basken
Misumi

Yes, and we are expanding our standardization of customer custom machined products into our standard configurable products, kitting services, and exploring light sub assembly services.

Ultra Motion’s new A2 Servo Cylinder is a ruggedized, IP65 (IP67 static) electromechanical linear actuator with integrated Phase Index absolute position feedback and advanced brushless dc control electronics. Made in the USA, the A2 Servo Cylinder is designed for simple integration into applications requiring robust motion control in harsh environments.

Has your company added or expanded services to provide more in-house engineering support and upfront customization for your customers or their end users? Tell us about that and what problems you are eliminating for your customers by doing some of the integration for them.

Tom Quartararo
Ultra Motion

The analog signal operation mode of the Servo Cylinder has proven to be extremely popular and effective in applications that require precise motion control over the entire range of travel. The combination of long life mechanical components, control electronics, and absolute position feedback greatly reduces cabling, system complexity, and the number of vendors associated with a project. Our Phase Index absolute position sensor is contactless and batteryless, which increases system reliability and eliminates the need for external sensors like limit switches, Hall effect sensors, encoders, and linear potentiometers.

Aaron Dietrich
Director of Marketing
Tolomatic

Tolomatic has always worked with customers wants and needs to provide customized engineering solutions. In fact, an increasing trend for Tolomatic is to modify existing designs to meet unique customer demands. Simple modifications such as integrating specialized mounting features are common, but more complex requests involve integrating position and force sensors into actuators.

Ben Lutz
LinMot

Our company has hired more engineers for the support role, and we maximize their time through remote sessions and virtual meetings. The creation of AOIs and other programming function blocks have made digital motion accessible to a wide range of PLCs and Numerous short tutorials have also been produced to reduce the strain on new integrators.

David Basken
Misumi

Yes, we have expanded the in-house engineering team to meet the demand of our rapid growth as well and further deepen the level of application and component selection support we offer. We find that designers are having to work on shorter timelines, and therefore are looking for more support from suppliers to offset some of that work.

Keith Knight
Product Line Design Manager
Haydon Kerk

Over the past couple of years, we have experienced a trend that more and more of our customers have benefited from releasing some portion of their design to a qualified motion control partner. In many cases our customers have a great deal of expertise in their specific field, but that field is not necessarily motion control. By teaming up with a qualified motion control company they can reduce their development timeline, risk, and ultimately release their product to the market sooner and gain more market share.

Haydon Kerk Motion Solutions and Pittman are groups within Ametek’s Advanced Motion Solutions division (AMS) that are built on providing a high degree of support and customization. An engineering group within the company focuses on higher-level systems projects apart from the core product offering. These projects range from highly customized single axes of motion that simplify overall assembly to larger scale multi-axis solutions that incorporate multiple technologies for load guidance, mechanical drive mechanisms, motors, and customized feedback.

What industries are most changing motion-component design? What industries or applications are using more custom components than in the past and why?

Tom Quartararo
Ultra Motion

Motion control in UAVs/UGVs often uses electromechanical rotary actuators, but a linear system can increase overall performance while reducing linkage complexity, cost, and weight in many applications. The Ultra Motion Servo Cylinder includes a mode to move to a proportional position as commanded by an RC-PWM (1 to 2 msec pulse) signal, which is offered as a standard servo control output in many commercial autopilots. Phase Index absolute position feedback eliminates the need to home the actuator at startup, which is a critical feature for control surface applications since homing is intolerable in the event of a power glitch. The native RC-PWM control mode coupled with high reliability Phase Index absolute position feedback and the extremely dynamic motion capability of the Servo Cylinder offers a great combination for unmanned vehicle applications. Detailed control and diagnostic information is available through the Servo Cylinder’s RS-232 command interface for telemetry purposes or for more sophisticated control and decision making. The Servo Cylinder has successfully replaced rotary actuators on unmanned vehicles in applications such as control surface manipulation, throttle control, and landing gear deployment.

Aaron Dietrich
Director of Marketing
Tolomatic

We see a lot of change happening in the food and beverage environment, with the continued increased enforcement and effect of the FSMA (Food Safety Modernization Act). This has driven customers to demand more hygienic designs from all the components they use. Due to the increased demand for more hygienic designs, Tolomatic is taking more standard product and customizing into hygienic designs that meet their requirements.

Ben Lutz
LinMot

Very few industries can tolerate frequent changing motion components. In fact, new technology like the LinMot tubular linear motor technology takes many, many years to become an adopted and accepted alternative to traditional point-to-point motion. Europe is leading here as the European OEMs adopt new technology more readily and drive their business through new motion component technologies, creating faster, smarter and more flexible machines. Custom components are used in all industries but many customers find it easier to select from standard dimensions to reduce concern about replacement parts.

David Basken
Misumi

Automotive is introducing different materials and technologies into automobiles faster than ever, and this brings with it unique engineering challenges for the automation equipment to handle these. The most influential now are aluminum body panels for vehicles, and the rise of the Electric Vehicle and the battery-based powertrain.

You can read Part 2 of this series on linear actuator trends here.

Genesis Robotics premieres LiveDrive actuator at Hannover Messe 2017

April 26, 2017 By Lisa Eitel Leave a Comment

Canadian manufacturer Genesis Robotics unveiled LiveDrive — the first highly-controllable direct-drive robotic actuator that is three times faster and 100 times more precise than conventional actuators — at Hannover Messe 2017 in Germany on April 24th.

Robotic actuators are the physical force behind robots, and make up approximately 30 percent of the cost. For more than 50 years these actuators (the combination of a motor and gearbox) have remained relatively unchanged, resulting in clunky robots that are limited in movement and precision and are largely unsafe around humans.

LiveDrive’s thin and flexible design eliminates the gearbox from the actuator, and with it, goes the jerking sensation you see in many robots, known as backlash. With no backlash, high torque (or power), and instant stopping capacity, LiveDrive makes it safe for humans to be assisted by robots, a vision founder and CTO James Klassen had from the onset. It also reduces the cost of developing robots by approximately 50 percent.

“Imagine a world where rehab involves putting on an exoskeleton and programming it to do your physio exercises, or where healthcare, military and factory workers can have robots assist them with the heavy-lifting required to do their jobs,” said Klassen. “Our vision is a world where humans can be assisted, not replaced by robots, improving overall quality of life. LiveDrive makes this possible, as the technology makes it safe for humans and robots to interact.”

LiveDrive is the result of three foundational discoveries. The first discovery uses the strongest magnets in the world and amplifies them, nearly doubling their force. This force would collapse a conventional motor. To harness this magnetic performance, a second discovery was made to design a rigid structure that can withstand the force. A motor with this power would normally generate extreme heat, making it unusable. However with the third discovery, the LiveDrive has a unique design that dissipates heat in a way that that allows for optimal performance.

“We worked to address the limitations of traditional robotics to usher a new era, which will improve the lives of workers and revolutionize entire industries,” said Mike Hilton, CEO of Genesis Robotics. “Robots today present safety and productivity concerns for both workers and employers. Our actuators enable robots to stop instantly. This along with the numerous other benefits of LiveDrive opens up new possibilities for faster, safer, more versatile robots that improve the human experience.”

LiveDrive is on display for the full 5 days of Hannover Messe and live presentations will be given by the Genesis team in Booth D66, Hall 17.

Steinmeyer announces The Pentagon Company as new sales representative for Western U.S.

March 28, 2017 By Miles Budimir Leave a Comment

Steinmeyer has announced that The Pentagon Company will be its new representative for miniature ball screw products in USA’s western states. President of Pentagon, Donna Materna, will team-up with her sales engineers, Mike Peterseim, Al Theis and Art Kuller to represent Steinmeyer. Known as the “application detectives,” The Pentagon Company has a well-established history of focusing on highly specialized mechanical components for medical, laboratory, industrial, semiconductor and aerospace OEM applications. They have over 50 years of experience working with mechanical design engineers to provide them with top of the line support.

As a highly experienced technical sales organization specializing in premium engineered products, Pentagon will greatly strengthen the exposure of Steinmeyer’s German engineered, high quality miniature ball screws. Please contact Donna Materna at 818-785-5112, or email donnam@pentagonco.com to inquire about Steinmeyer’s custom and standard solutions for drive applications that require precise, premium miniature ball screws. Pentagon’s website is www.pentagonco.com.

For more information contact Bruce Gretz, V.P of North American Sales, at (781) 273-6220 or bruce.gretz@steinmeyer.com.

www.steinmeyer.com

Technologies from Bosch Rexroth you missed at MD&M West

February 18, 2017 By Lisa Eitel Leave a Comment

MD&M West is known for its unwavering usefulness to attendees and exhibitors alike, and this year’s event delivered as usual. Here’s what we saw at the Bosch Rexroth booth (within the colocated ATX West) during our visit at the show.

A main focus at the Bosch Rexroth booth was connected automation technology — also called the Internet of Things, IIoT, and Industry 4.0 — depending on the context and who you ask. Showcasing Bosch Rexroth offerings here was an Open Core Engineering demonstration — in the form of spreadsheet-based networked control of a multi-axis Cartesian system. Read more about the related offering — Rexroth Open Mechatronics — and the demonstration at ATX West here. There’s an explanatory video at the link.

Here, Richard Vaughn of Bosch Rexroth explains how (thanks to the Open Core suite of products) he is controlling the multi-axis setup in the background through a custom program on his tablet.

In short, Open Core Mechatronics is multi-axis motion control and programming that lets engineers access the core of Rexroth’s motion-logic drive and control platforms … so they can use familiar IT languages (MATLAB, LabVIEW and even Visual Basic for Applications or VBA and Java) to write automation functions and applications.

Software engineers can also streamline HMI programming through Rexroth’s Open Core Interface.

Leveraging predefined software functions, machine builders can create custom interfaces in the form of mobile apps or HMI screens — to let users perform machine functions and collect data from virtually anywhere.

Other items Bosch Rexroth had on display at ATX West were their second-generation electromechanical cylinder with a hygienic design; details on their new microsite for resource kits; details on their Factory Automation Road Show traveling truck of technology; and their TSplus and VarioFlow plus conveyors:

Prototype in 2015 — and now the product is here to replace factory whiteboards

Bosch Rexroth also showed the new release of something I saw as a prototype with my colleague Mary Gannon back in 2015 — a digital iteration on the old-school whiteboard so common on factory floors for tracking production data.

Here’s a little tweet from that 2015 visit with Bosch Rexroth with Morrell Group graciously hosting … 3D-printing and other technologies were on display:

Precision #3Dprinting from #voxeljet at #RexrothI40 event at @morrellgroup | Prints of sand for direct #moldmaking pic.twitter.com/AW3Y2bjA6f

— Elisabeth Eitel (@EitelonDesign) September 15, 2015

Called the Manual Production Systems & Active Cockpit, this digital communication station lets workers and managers access production data.

Manual assembly will always be part of manufacturing. So to serve this portion of the factory floor in a modern way, Rexroth’s Active Cockpit connects to data-sensing manual and automated processes to give plant personnel a realtime view of production data, work instructions, meeting minutes — whatever information is needed for instant access to boost production.

Paring this technology with Rexroth’s Manual Production Systems (MPS) makes manual jobs even more efficient. (With Rexroth’s reconfigurable aluminum framing, MPS makes lean manufacturing easy and lets manufacturers adapt quickly to changing demands.) As literature we got on the product explains, Active Cockpit is an interactive web-based communications platform that detects all relevant data for a production line, updates it in a dynamic manner, and visualizes it clearly in realtime, directly on the line:

ActiveCockpit software from Bosch Rexroth delivers Industry 4.0 technology straight into users’ hands as it records, processes and visualizes manufacturing data in real time. So IT applications such as production planning, quality data management and e-mail dispatch connect with software functions from machines and systems. Key metrics clearly display in realtime in the most appropriate format — so on a large touchscreen directly at the manufacturing line or on an interactive tablet onsite, for example.

Personnel can immediately see production problems to initiate corrections based on all relevant data. For more information, visit boschrexroth.com/en/us/activecockpit.

Smattering of other items at the Bosch Rexroth booth

Below are details on a few other items Bosch Rexroth displayed at ATX West — enjoy. Also note that Bosch Rexroth will be showing at CONEXPO-CON/AGG 2017 in Las Vegas March 7 through 11. Catch them at IFPE – South Hall 3 – S80214 if you’re attending.

Right turn for higher energy efficiency: Frequency converters from Rexroth

Rexroth IndraControl XM series programmable logic controllers integrate I/O for speed and flexibility

VarioFlow plus expands application range for conveyors

Rexroth ball-screw assemblies increase service life by 80%

FAQ: What are low voltage piezo actuators, and where are they used?

October 8, 2016 By Danielle Collins Leave a Comment

When voltage is applied to a piezo ceramic material, the material experiences a displacement (expansion or contraction) per the inverse piezoelectric effect. The amount of displacement that results from the applied voltage depends on thickness of material. Thus, for a given displacement, a thinner material requires a smaller voltage than a thicker material. Low voltage piezo actuators are generally classified as those that operate below 200 V.

The inverse piezoelectric effect refers to the strain that is induced on a piezo material when it is subjected to an electric field (V/m).

Multilayer piezo actuators take advantage of very thin individual layers to keep the required voltage low.
Image credit: Physik Instrumente

Low voltage piezo actuators are typically based on a multilayer, or stacked, design, in which very thin layers of piezo ceramic material are electrically connected in parallel. The multilayer design exploits the benefit of smaller thickness to reduce the required voltage, while the parallel connection scheme maximizes the total displacement.

How it works

A low voltage actuator uses layers that are just 50 to 200 microns thick each, sintered together. Because the required operating voltage is based on the thickness of each layer, rather than on the total length of the actuator, the required voltage is kept low. However, the total displacement of the actuator is the sum of each layer’s individual displacement. The result is an actuator that operates at a low voltage but produces a large displacement.

When operating well below its resonant frequency, a piezo actuator behaves like a capacitor, and its displacement is proportional to the stored electrical charge. Capacitance is proportional to the cross-sectional area of the actuator (perpendicular to the direction of the electric field) and inversely proportional to the thickness of each layer.

Where:

C = capacitance (F)

n = number of layers

ε = dielectric constant (As/Vm)

A = cross-sectional area of the actuator (m²)

T = thickness of each layer (m)

Note that the capacitance of piezo ceramics varies with the amplitude of the voltage, the temperature, and the mechanical load. Be sure to check the conditions (voltage, frequency, and temperature) that were used by the manufacturer to determine the published capacitance values.

Low-voltage piezo actuators are used in applications where the required force is in the range of several dozen kilograms (as opposed to several thousand kilograms with high voltage actuators), such as nanopositioning. And because their voltage requirement is very low, they are also well-suited for applications where power is supplied by a battery, such as consumer electronics equipment.

Feature image credit: Physik Instrumente

FAQ: How do I calculate the inertia of a servo-driven system?

September 29, 2016 By Danielle Collins Leave a Comment

Inertia, or more specifically, inertia ratio, is one of the most important factors in sizing a servo system. Inertia is defined an object’s resistance to change in velocity, and in servo-driven systems, it can be used as a measure of how well the motor is able to control the acceleration and deceleration of the load. The yardstick by which this is judged is the inertia ratio, which is defined as the inertia of the driven component(s) divided by the inertia of the motor.

J_L = inertia of load reflected to motor

J_M = inertia of motor

An inertia ratio that is too low means the motor is likely oversized, leading to higher than necessary cost and energy usage. An inertia ratio that is too high means the motor will have a difficult time controlling the load, which results in resonance and causes the system to overshoot its target parameter (position, velocity or torque).

While it seems logical that an inertia ratio of 1:1 would be the goal, it’s not always achievable or cost-effective. Most servo motor manufacturers recommend that the inertia ratio be kept to 10:1 or less, although there are many applications that operate successfully at much higher ratios. The best inertia ratio for an application comes down to the dynamics of the move and the accuracy required.

How to calculate inertia of a drive system

Load inertia includes the inertia of all rotating parts, including the drive (such as a belt and pulley system, screw, or rack and pinion), the load being moved, and the coupling between the load and the motor.

J_L = inertia of load reflected to motor

J_D = inertia of drive (ball screw, belt, rack & pinion)

J_E = inertia of external (moved) load

J_C = inertia of coupling

Manufacturers typically provide the inertia value (or a simple equation to calculate the inertia value) of drive systems, such as ball screws. But if the inertia value isn’t provided, it must be calculated manually. One of the most common ways to do this is to model the drive system as a shape for which the inertia equation is easily defined. Some common examples are solid cylinders and hollow cylinders.

Inertia of solid cylinder (screw or pinion)

Inertia of hollow cylinder (pulley)

m = mass of cylinder

r = radius of solid cylinder

r_o = outer radius of hollow cylinder

r_i = inner radius of hollow cylinder

How to calculate inertia of a load

To determine the inertia of a screw-driven load, the effect of the screw’s lead must be taken into account.

Inertia of load driven by screw

m = mass of load

l_s = lead of screw

Note that this equation is based on the screw’s lead (expressed as inches or mm per revolution), not on the pitch (expressed as revolutions per inch or per millimeter).

When a load is driven by a belt and pulley system, the mass of both the load and the belt must be considered, since both of these components are being driven by the motor. Rack and pinion systems are treated similarly, with the mass of the pinion being added to the mass of the load.

Inertia of load driven by belt (or rack and pinion)

m = mass of load + mass of belt (or pinion)

Also, the radius in this case is the outer radius of the pulley, since this is the axis around which the belt and load are being rotated.

How to reduce inertia ratio

If the inertia ratio is too high, one way to reduce it is to add a gearbox to the system. In this case, the inertia of the load is divided by the square of the gear ratio.

Inertia of load with gear reduction

J_G = inertia of gearbox

i = gear ratio

Note that the inertia of the gearbox is added to the system, but its addition is small compared to the reduction provided by the gear ratio, which has an inverse squared effect on the load inertia.

If you’re not done calculating, check out our list of engineering calculators.