Linear Motion Tips, a leading source for engineering and manufacturing information, provides engineers and industry experts with articles, tips and guides to assist in knowledge and job performance. The linear actuators, ball screws and lead screws articles below can be used as a professional resource.

New HepcoMotion® PSD80 Profile Screw Driven Unit from Bishop-Wisecarver

Pittsburg, CA - Bishop-Wisecarver Corporation announces the availability of the new HepcoMotion® PSD80 Profile Screw Driven Linear Actuator with high efficiency Herculane® wheel technology. Designed to complement the established PSD120 ball screw actuator, PSD80 has been primarily developed around the need for a cost effective Z axis solution in lighter load applications such as pick and place and assembly operations.

Housed on a high strength aluminum beam and fitted with a stainless steel sealing band, the PSD80 uses Herculane wheels mounted to an adjustable carriage, offering long life and no re-lubrication. Single or multiple carriages on a unit are possible and can handle loads to 500N. A stainless steel lead screw provides actuation with pitch ranges of 4, 15, 25 and 70mm. The 25mm lead is particularly useful in Z axis applications, while the 70mm screw pitch satisfies the higher speed pick and place requirements and allows speeds up to 1 m/s and thrust loads to 300N. The lead screw is available in right and left handed threads and offers smooth, strong and precise actuation. A ball screw can be supplied for applications that require greater positioning accuracy.

PSD80 is supplied as a closed or open format dependent upon the application being subject to the ingress of dirt. The closed unit is rugged, tolerant of debris, and offers many mounting options while the open version is a lower cost solution that is compact, light, and has low friction. Where two units are to be used in parallel, a “slave axis” without the driving screw can be specified for both closed and open units. Adding to its flexibility, the PSD80 is available in a completely corrosion resistant version, as well as a double acting version for applications that require symmetrical movement from opposing carriages.

Bishop-Wisecarver
www.bwc.com

New Precision, Multi-axis Air Bearing Gantry System from Steinmeyer

BURLINGTON, MA — Steinmeyer, Inc. announced a new precision, multi- axis air bearing gantry system. This motion system consists of an XY stage utilizing air bearings plus a conventional ball screw driven Z table. It is ideal wherever there is a need for ultra high precision and outstanding dynamic performance.

Typical uses include:

- laser machining
- inspection systems
- pick and place devices
- dispensing systems, and
- gene chip production equipment.

These stages (which may be completely customized) achieve the following standard XY specifications: travel is 600 mm X 600 mm, positional accuracy is 10 microns, positioning repeatability is +/- 1 micron, straightness and flatness is 1 micron. Both X and Y stages are driven by ironless, electrodynamic linear motors with maximum acceleration of 10 m/s² and velocity of 1000 mm/s. Position feedback is accomplished via an incremental linear encoder with a resolution of 50 nm. Typical Z stage performance includes: 25 to 200 mm travel; positional accuracy of 10 microns; and repeatability of +/- 1 micron. A separate motion control option is available based on customer specifictions.

Steinmeyer
www.steinmeyer.com

Miniature Metric 8×6 Ball Screw from Nook Industries

Cleveland, OH - Nook Industries has recently introduced its miniature metric 8×6 Ball Screw (BS) designed for light load applications that deliver fast speed and close tolerance positioning. The rare size (8mm diameter x 6mm lead) is the only precision-rolled 8×6 on the market and is designed for compact applications that require the dual ability to be fast and precise−ideal for accurate positioning requiring a rapid approach and retraction.

Nook’s Precision Screw Group originally developed the 8×6 BS as part of its Miniature Metric Ball Screw Development Project primarily for medical applications. The combination of small screw and high-precision, however, is also well suited for a myriad of broad-based light load applications requiring close positioning and fast speed including; military, optics, instrumentation, sensors, etc.

Nook’s 8×6 BS is manufactured using precision rolled technology instead of grinding − which significantly lowers cost without compromising precision. Custom ball screw end machining options are also available to accommodate custom motor/bearing combinations.

Nook Industries
www.nookindustries.com/8×6

Schaeffler Plant Produces One-millionth Ball Screw Drive

A ceremony took place recently to celebrate the one-millionth ball screw drive to leave Schaeffler’s fully automated production plant in Herzogenaurach, Germany. Attending the ceremony were Maria-Elisabeth Schaeffler (Owner), Dr. Peter Pleus (President Schaeffler Group Automotive), Dr. Christoph LÖffel (Head of the Ball Screw Drive Product Line) and Peter Wirkner, Plant Manager at Herzogenaurach.

Manufactured at the Herzogenaurach plant since 2007, Schaeffler’s energy efficient ball screw drive is being utilised on the electromechanical steering system for the Volkswagen Tiguan. Schaeffler supplies the ball screw drive to Volkswagen, as well as a toothed rack, which is partly designed as a spindle on which the drive is located. Ball screw drives are used to transform rotary motion into linear motion through a direct coupling between the drive element and the output element. In the Tiguan, the ball nut is driven by a servomotor, which is linked to the ball screw drive via a belt.
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New Miniature Ball Screw Series from Steinmeyer

BURLINGTON, MA — Steinmeyer, Inc. has announced a new product to its extensive line of miniature ball screws. These 5mm diameter screws are the perfect solution in applications such as micromanipulators, miniature robotics and compact actuators.

Available in four nut styles, series 1112 single nut with connecting thread without wipers, series 1412 is a single nut with double flange and wipers on both ends, series 1214 is a cylindrical nut without wipers and series 2422 is our “quiet line” series, with a single nut that uses end-cap ball returns manufactured from plastic rather than metal tubes, making the screw virtually noiseless. All are available with leads ranging from 0.5 mm-3 mm and offer a maximum speed of 4500 RPM.

Steinmeyer
www.steinmeyer.com

Guide to Motion Solutions for Packaging Applications

WOOD DALE, IL –Thomson has available a new Guide to Motion Solutions for Packaging Applications that offers information on how to leverage motion technology to design and build optimized packaging and related material handling machines.

Specific examples with detailed 3D application renderings include pick-and-place/palletizing, label printing/scanning, stretch wrapping, carton packing, PET bottle manufacturing and filling machines. The guide also provides an overview of the company’s linear motion and related components for packaging machinery including profile rails, RoundRail linear guides and components, lead and ball screws, linear actuators, precision linear actuators, linear motion systems, clutches and brakes, and gearheads.

Thomson
www.thomsonlinear.com

Anti-backlash Leadscrew System

EAST PROVIDENCE, R.I. – igus® has unveiled a new addition to its line of DryLin® SLW leadscrew tables. DryLin SLW Pre-Loaded uses anti-backlash nuts to reduce axial clearance and is also fitted with DryLin W ‘turn-to-fit’ linear bearings, which offer adjustable radial clearance.

DryLin SLW Pre-Loaded is available off-the-shelf and is less expensive when compared to ball bearing assemblies. Costs associated with research, design, drawing, purchasing, QC, and assembly are virtually eliminated. In contrast to other linear shaft systems, DryLin SLW Pre-Loaded also features high torsional stiffness and is completely lubrication-free and contaminant-resistant.

The clearance on the DryLin W carriages can be adjusted with an Allen wrench. The setscrew makes an audible clicking sound with every increment of adjustment, which helps the end user achieve consistent and quick assembly every time. This new technology makes higher-precision applications possible at a lower cost.

“The pre-loaded version of our DryLin W Adjustable provides design engineers with more options,” said Matt Mowry, product manager for linear technology at igus North America, “Instead of buying a number of different components to piece together an assembly, they can purchase a high-performance part from our catalog and use the time saved to design several other aspects of their equipment.”

igus
www.igus.com

Thomson Introduces New Website

WOOD DALE, IL –Thomson introduces Thomsonlinear.com – a content rich site detailing the company’s comprehensive family of mechanical and electromechanical motion solutions, along with a vast array of helpful, time saving and performance optimizing design tools and educational/training resources. Visitors are also able to browse potential motion solutions by industry of interest. Each resource is provided to engineers streamline the design process and optimize the performance of their machine through quick specification of best in class components and systems.

Machine builder’s will quickly find all relevant features, benefits, specifications and ordering information for Thomson actuators, ball screws and lead screws, clutches and brakes, linear bearings and guides, linear motion systems, precision balls and planetary gearheads. They are also able to browse potential motion solutions by industry, including aerospace and defense, electronic assembly, lift truck, medical, mobile off-highway, packaging and converting, personal mobility, semiconductor and textile.

Perhaps most significantly, OEMs have access to the company’s comprehensive and substantive library of design tools and education/training resources, including:
•Sizing software such as Linear MOTIONEERING® and Micron MOTIONEERING® to automate the linear system and planetary gearhead sizing, selection and quoting process
•Attribute-based Product Selectors that automatically identify the optimum components based on user inputs
•On-demand and live technical, educational and non-commercial webinars
•An Engineer’s Toolbar that provides a convenient method of performing common technical calculations
•Configurable 2D and 3D CAD drawings in all major CAD formats
•A library of technical articles and white papers
•Thomson eNews – a monthly enewsletter that covers a wide range of topics including application design, problem-solving insights, product introductions and selection, available literature and online software tools

Machine builders can also check out the company’s training schedule and enroll for upcoming courses, and even request customized, on-site training.

Thomson
www.thomsonlinear.com

Motion System Drives Realistic Racing Experience

by Leslie Langnau, Managing Editor

After many years of evaluating and working with motion systems for various clients, UK-based Ball Racing Developments Ltd (BRD) concluded that nothing on the market could accurately simulate a racing car’s motion. So, the management and the engineers developed a new type of system dedicated to the motions experienced in a racing car, particularly the high velocity forces of a Formula One car for use in racing driver training, entertainment, and private owners with a keen interest in motorsport.

The first of this new generation of dedicated driving motion systems was released in November 2007 and sent to a theme park in Macau that wanted accurate motorsport simulators. However, BRD was unhappy with the performance of the equipment offered by its existing supplier of motion control products. The simulation technology specialist wanted a more compact and higher performing motor system, a specification that was ultimately fulfilled by Wood Dale, Ill. based Kollmorgen AKM-7 and AKM-6 brushless AC servomotors and Thomson linear systems.

The motors offer 0.16 to 53 Nm torque and speeds up to 8,000 rpm in a compact frame-size. This is an important factor to BRD, where any weight savings can benefit system performance and reaction times. The AKM motors were about half the size of the conventional servomotors they replaced.

One motor is required for each degree of freedom on the V1-500 motion platform. One AKM-7 motor handles movement in the surge direction (forward and backward acceleration and deceleration). AKM-6 variants handle motion in the side slip (side-to-side lateral thrust) and yaw (angular motion in the horizontal plane) directions. Yaw is achieved by changing the centre of rotation between the front and rear wheel positions. Each motor is powered by a Kollmorgen S600 AC servo drive, a digital servo amplifier.

For two motion platforms bound for Singapore, the engineers decided to include Thomson ball screw and linear guide systems in the same package in order to reduce lead-time and simplify the build process. These platforms were completed in just 10 weeks from signing the order, including design, build, and installation.

Three 40 mm x 40 mm ball screw assemblies move the Formula One car mounted on the motion platform. All are the same length for commonality purposes and each offers 1.2 m of travel. These assemblies consist of a precision rolled screw shaft and a nut (the outer race) with an internal groove and circuits of precision steel balls that re-circulate in the grooves between the screw and nut. This backlash-free anti-friction design converts torque to thrust as either the screw or nut turns and the other component moves in a linear direction. These ball screws have a high lead, which is necessary to generate the required 1 m/sec acceleration.

Alongside the ball screws and supporting the loads and high acceleration forces is a pair of 500 Series Profile Rail linear guide systems. These configurable linear guides meet DIN standard 645-1 requirements. Their rigidity and load capacity withstands the acceleration forces experienced in this realistic F-1 simulation. BRD had the option to plate linear guide bearing systems with thin-dense chrome (TDC) to withstand the exceptionally humid atmosphere in Singapore.

When mechanically complete, the two motion control platforms were linked with visual and sound technology created by BRD by mapping and modeling the Singapore street circuit. Based on BRD’s netKar Pro software platform, anyone can download a free copy of the Singapore night race circuit from www.singtelrace.com and practice driving the difficult track that twists and turns it way around many of Singapore’s famous landmarks. Users can even post lap times to the on-line leader board to see how they compare with others.

The two racing simulators deliver a realistic racing experience, short of being in an actual race car. At one point, crashing into the barriers produced such a sudden jolt that the effect had to be softened by BRD in the interests of health and safety. Approximately 1.0 to 1.5 G force can be generated in each axis of motion by the platform. As an added safety measure all drivers have to wear a four-point racing harness.

There has been plenty of interest from racing teams; a leading Formula One driver tested the V1-500 and managed to reduce his lap time by 0.7 sec. He noted that the system provided him with a greater ‘feel’ for effects present in a real racing environment such as under-steer, over-steer, weight transfer braking and wheel-spin, and helped improve his reactions.

Thomson
www.thomsonlinear.com

Kollmorgen, a Danaher Motion Co.
www.danahermotion.com/kollmorgen

Rexroth CKK Ball Screw Actuators Raise Performance for Wind Turbine Builders

Wind turbine technology is an established sustainable, green technology. Many consider it a technology that will help define the energy future. But wind energy also depends, to a great extent, on more traditional manufacturing techniques, such as welding – vitally important for creating the massive towers.

One of the leaders in creating welding solutions for the energy industry – as well as many other applications – is Rexburg, ID-based machine builder AMET Inc. (www.ametinc.com). Recently, AMET called upon the Linear Motion and Assembly Technology specialists of Bosch Rexroth to help them create a new generation of custom welding systems for the increasingly important wind energy industry.

The design of AMET welding equipment – and the role of linear motion technologies – is largely dictated by the techniques required to create massive wind turbine towers that can be around 90 meters high (close to 300 feet). During a weld, while the bulk of the equipment remains stationary, the weld head constantly moves small distances along at least 2 axes, both along and across the seam. A linear control actuator mounted at the end of a horizontal arm determines the motion of the weld head.

AMET’s goal was to create a cost-effective, dependable welding system that could perform accurate longitudinal and circumferential submerged arc welding. One of the most important challenges, however, was to assure smooth and precise (within 1/100th of an inch) control of the weld head, to avoid improper welds that would need to be redone and ultimately result in wasted time and materials. And this precise control had to be maintained within a very demanding environment. “The tremendous amount of particulates, especially flux dust, generated by this form of welding can really cause problems for this machine’s finer controls, particularly with systems such as linear actuators,” said Craig Dees, AMET Engineering Manager.

AMET also wanted linear motion elements that offered good strength (dynamic loads in excess of 20,000 Newton) with light weight and compact size. Yet another challenge was to support smooth weld head acceleration of up to 3 meters per second squared (3m/s2), for a travel speed of 1.5 meters per minute.

To meet these needs, AMET turned to a familiar source for linear motion: Northwest Motion, Inc. (www.nwmotion.com), a distributor of Rexroth linear motion products. Rexroth precision-ground, hardened steel guide rails were to be specified for the guide rail that carries the suspended weld head for outside welding. With the CKK Compact Modules, however, AMET put Rexroth linear motion systems in a particularly crucial role.

The compact CKK design, light in weight but durable and strong, makes machine assembly smoother and easier. “We knew that other linear motion solutions couldn’t give us the reliability and protection against contamination and pitting that the CKK modules could,” Dees says.

Another important feature leading to better and faster machine production is the fact that CKK 20-145 modules are complete, prepackaged systems, with dual ball rails and a ball screw drive integrated into the module. This simplifies design, saves space, and removes the costs and effort of machining, assembly, bearing alignment and other application engineering tasks.

Download the complete case study from the Bosch Rexroth Case Studies & Technical Papers web page.

Bosch Rexroth
www.boschrexroth-us.com

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