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 drive belt system and linear drives articles below can be used as a professional resource.

SICK STEGMANN Introduces TTK70 Motor Feedback System

DAYTON, OH – SICK STEGMANN, INC. introduces the TTK70 Motor Feedback System.  The TTK70 is an absolute, non-contact linear measuring system that delivers measuring lengths up to 4,000 mm, resolution of <1 μm and system accuracy of <10 μm, at operating speeds up to 10 m/s.  The result is precise and highly reliable absolute position determination for linear motors in a diverse range of applications.  The TTK70 motor feedback system is rated for operation in temperatures ranging from -30…+85°C.  It carries the CE mark and is RoHS compliant.

The TTK70 consists of a read head and a magnetic tape featuring a magnetic code that forms the measuring scale – 10 mm wide, and up to 4,000 mm long.  The code consists of an incremental and an absolute track (twin-track tape).  Absolute position values are calculated by the read head first detecting the absolute starting position during start-up of the linear motor.  All further positions of the drive are determined via the incremental position on the magnetic track, i.e. sine/cosine signals.  The values are transmitted via the HIPERFACE® interface to the evaluation electronics of the linear drive – a market-standard method of communication that, for the first time ever via the TTK70, is now available for linear measuring systems.  The result is an interface standard for all common servo drives, that covers all applications, with only one signal type.

The robust metal housing of the read head offers IP65 protection, has two mounting holes designed for high tightening torques and, even with the plug connection, is hardly bigger than a matchbox – making it the smallest system of its kind.  Inside, the TTK70 features the latest in sensor and evaluation technology.  The sensor PCB, which is aligned with the measuring plane, is equipped with Hall sensors on two parallel tracks.  When installed their placement coincides with the position of an incremental and an absolute track on the magnetic tape.

SICK-STEGMANN is currently the only supplier worldwide that is able to offer to drive manufacturers both rotary and linear motor feedback systems with an integrated HIPERFACE® interface, popular in applications such as erosion machines, handling systems in semiconductor production, automatic assembly and placement machines, vertical lifting systems, pick and place applications in electronic production, or the food industry.

SICK STEGMANN, INC.
www.stegmann.com

Kübler by TURCK Magnetic Linear Encoders

Minneapolis, MN — TURCK introduces a new line of Kübler by TURCK robust magnetic linear encoders. Utilizing A and B output voltage channels plus a periodic index with the corresponding inverted channels, these encoders achieve high accuracy in a broad range of linear motion applications. The T8.LI20 and T8.LI50 linear encoders are available with either a push-pull output or an RS422 interface and provide a voltage range from 4.8 to 30 VDC.

The linear encoders are used with magnetic bands that are attached to the mounting surface and protected by a stainless-steel cover. The encoder’s resolution is up to 5 µm with quadruple evaluation, and its repeat accuracy is +/- one increment with a measuring speed up to 82 feet per second, depending on the resolution.

Kübler by TURCK encoders use non-contact technology and can survive environments with high vibration (30g/10-2,000 Hz) and shock (500 g’s/1ms). The products can also be used outdoors, due to an IP 67 protection rating, wide temperature range and the weatherproof die-cast housing. The metal housing also offers improved shielding against electromagnetic interference.

A built-in LED provides a warning signal or an index pulse, allowing for simple set-up and diagnostics. Connections are made via a high-grade shielded PUR cable that is also suitable for cable track installations.

TURCK
www.turck.us

Micropulse Generation 7 Linear Position Transducers from Balluff

Florence, KY – Balluff has introduced the first of its new Micropulse Generation 7 linear position transducers, featuring improved measurement and environmental specifications, longer lengths, and more flexible setup than previous models. Debuting in the analog rod style housing, Generation 7 is available in two versions, Micropulse and Micropulse Plus. Micropulse is fully backward compatible with Balluff’s Generation 5 products, yet delivers better measurement performance and environmental ratings. The advanced version Micropulse Plus features flexible output scaling and configuration using a PC interface.

Performance improvements include stroke lengths to 300 in. with the maximum non-linearity cut in half. This features ±50 µm for nominal strokes less than 500mm,  ±0.01% of full scale for 500 to 5500mm, and ±0.02% of full scale from 5501mm to 7600mm. Shock ratings are to 150g and vibration rating to 20g. EMC severity for static, RF, burst, and line noise is Level 3; for surge, Level 2 and magnetic field immunity to Level 4. Additionally, housing protection is to IP68 for pre-wired cables and IP67 for connector models.

Other improvements allow easier and more flexible configuration options during setup. Dual bi-color LEDs handle double duty for diagnostics and as a setup aid for pushbutton scaling of the position outputs. Communicating to a PC over standard USB, Micropulse Plus outputs can be scaled, inverted, and configured for single- or two-magnet position, velocity, or differential position between two magnets. Intuitive software features a simple-to-use graphical interface that allows drag-and-drop adjustment of the output characteristics. Configuration files can be saved for backup, replication, or for emailing to remote locations. Manual adjustment without a PC is also possible using the included pushbutton tool and simplified setup procedure that minimizes button-pushing complexity while maximizing operational flexibility.
For more information, visit:  http://www.balluff.com/btl7-z

www.balluff.com

IP69K Linear Position Transducer for Harsh Applications from Balluff

Florence, KY – Balluff’s new Micropulse® ProCompact linear position transducer for demanding linear feedback applications is rugged, accurate, and protected against environmental hazards such as high humidity, ambient temperature variations, high-pressure wash down, and exposure to caustic chemicals.

The Micropulse ProCompact rod-style transducer incorporates field-proven, non-contact magnetostrictive technology into a welded, hermetically sealed stainless steel housing providing superior long-term reliability and service life compared to competing contact-based sensors such as linear or rotary potentiometers.

The ProCompact is ideal for the following types of applications: hydropower and other wet applications, railroad maintenance equipment, steel production, sawmill applications, or any other application involving high humidity, ambient temperature variations, and high-pressure wash down.

The Micropulse ProCompact linear position transducer comes in standard ¾-in.-16 UNF (optional M18 x 1.5) mounting threads, allowing the transducer to be installed into hydraulic or pneumatic cylinders. Right out of the box, the ProCompact is environmentally protected to IP68. For even more demanding applications, the threaded fitting on the ProCompact housing can accommodate a cable protection system, offering environmental protection up to IP69K.
For more information, visit www.balluff.com/procompact

Linear Cable Transducer from BEI Industrial Encoders

BEI Industrial Encoders’ new linear cable transducer provides digital position and speed feedback information in a rugged, easy-to-install package. Model LT25 cable transducer utilizes a flexible measuring cable mounted to an internal spring-loaded spool and a quadrature encoder output to precisely measure linear motion applications. The sturdy cable is made of nylon coated stainless steel for ultimate strength and has a measurement range up to 125 inches.

Easy to install, simply connect the LT25 cable to your moving equipment and secure the base to a fixed object. Hard to reach areas or worries about shaft misalignment are now not a problem. The LT25 cable transducer allows for easy reorientation of the mounting bracket or encoder connector position, giving users added adaptability to their installation. With an IP66 rating, the LT25 is a perfect solution for a variety of industrial measurement challenges including wet, dirty, or outdoor environments or applications where your measuring range travels over a harsh environment.
For more information, visit www.beiied.com/cable-transducer

IP67-rated Magnetic Rotary Encoders for Heavy-Duty Applications

Southington, CT – For high resolution, high dynamic measurement of position, speed and velocity, Baumer has introduced the MHXX Series of hollow-shaft, large-bore, magnetic rotary encoders. These robust, non-contact encoders contain no bearings, so measurement is contact-free and components do not wear. The IP67 rated housing and fully encapsulated read head electronics allow long-term, reliable performance in high shock and vibration environments.

MHXX Series Magnetic Rotary Encoders operate efficiently in a wide range of temperatures, from -40 to 100ºC. All products in the line are compact, featuring very thin rotors and read heads that adapt easily to the axis of rotation. Specifically designed for use on shafts from 20 to 740 mm, the encoders are designed to allow large clearances between the rotor and the sensing head for easy mounting. The encoder’s disk may be mounted using set-crews, clamping rings, or clamping fixtures.

These IP67-rated encoders withstand vibration to 30g and shock to 300g. All encoders in the MHXX Series are available with incremental or sine-cosine outputs and certain models are also available with an additional absolute output track up to 17 bits. MH Series encoders offer large (+/- 3mm) permissible axial displacement and large (0.1 to 2.2mm) permissible air gap tolerance depending on size of bore.

MHXX Series Magnetic Rotary Encoders can be used on equipment and machinery used in motion control, textile production, wood/timber processing, packaging, machine tool, medical, electric motor and general industrial applications.

For more information contact Baumer at (800) 937-9336, or email at sales.us@baumergroup.com.

www.baumergroup.com/cameras

Pulsed-Inductive Sensor for Low-Cost Linear Position Feedback

Florence, KY – BIW Pulsed-Inductive sensors from Balluff only look like traditional resistive linear potentiometers. However, unlike linear potentiometers, BIW sensors use patented, non-contact technology to provide continuous, absolute, analog position feedback. Because there is no mechanical contact, wear is not an issue. BIW sensors are available at a price level equal to or lower than many linear potentiometers.

Like resistive linear potentiometers, BIW Pulsed-Inductive sensors are available with analog voltage outputs (-10 to +10V or 0 to +10V). But unlike linear potentiometers, these innovative linear position sensors are available with analog current outputs (0 to 20 mA or 4-20 mA) as well, without the need for external signal conditioning. This is important because analog current signals offer much better electrical noise immunity and allow for longer cable runs compared to analog voltage signals.

Balluff BIW Pulsed-Inductive linear position sensors are designed to be form-factor replacements for traditional resistive linear potentiometers, right down to the familiar sliding plunger. It also means BIW sensors are a perfect fit for linear feedback applications such as those found on plastic injection molding machinery, packaging machinery, hydraulic motion bases, and woodworking machinery. BIW sensors are also an ideal solution when low-cost, continuous position feedback is required on hydraulic or pneumatic cylinders.

For further information, visit: www.balluff.com/biw

Upgrade your motion system

Motion systems require upgrades for several reasons including obsolescence, cost, or technolog advancement. Such progress, however, is often accompanied by design and implementation challenges. How you handle these challenges will determine the success or failure of the change.

Recent
advancements in field programmable gate array technology enable digital
servo amplifiers like the Danaher Motion S200 family to achieve current
loop bandwidths of 3 to 5 KHz.

Typical advancements include replacing hydraulic and pneumatic actuation with step or motor driven actuators, changing step motors to servo, or replacing brush servomotors with brushless servos. The change from a step control to a servo control is typically less stringent than a move from a hydraulic or mechanical system to servo control. Electrical expertise for step motors and step drives is often available within a company. But in-house experts may not be available for hydraulic and pneumatic controls. With training and experience though, altering technology does not have to be daunting.

This
single acting, uni-directional hydraulic cylinder system is simple,
consisting of eight parts. For bi-directional operation, a more complex
and costly system would be needed.

Decrease variance to increase repeatability
Assume for a moment that you need to flow a liquid, semi-liquid or molten material at a specific rate. Should the material viscosity change between batches, achieving consistency with a hydraulic or pneumatic ram could be challenging. One remedy is to connect a PLC to a force cell to control the force in an on-and-off format. This is often referred to as Bang-Bang control and works great with the thermostat in a house, but is not really intended for the control of precision mechanics.

You may supplement this type of control with an exotic fuzzy logic scheme to round out the instantaneous changes, but this is not much more than “chattering” an input or valve to obtain a reduced rate of change. A servo actuator can replace an air cylinder and control both force and speed with the aid of a servo amplifier and without any special or exotic components. The position, velocity and current of a motor are constantly controlled to the specific tuning parameters required for the application.

Know your requirements
A detailed understanding of the application’s motion requirements is imperative. This understanding includes the mechanics, electronics, software, and dynamics (kinematics). Should your system require a point-to-point move for the pick-and-place of an electrical component, it may not be necessary to reduce following error to the minimum. Such misapplication may result in more effort in the control system, which can cause other issues such as resonance or heat buildup in the unit under control. In the case of a contouring or printing application, such an error is a direct measure of the output quality and must be considered.

Simulations and breadboards can increase your understanding of an application’s requirements. Accurate simulations reduce the number of false starts and re-designs, both of which waste capital and tax the creativity of the group.

This
simple electric actuator system ensures consistent bi-directional
operation. OEM machine builders obtain a low cost, easy to install,
high-performing device. End-users receive better control over critical
machine operations, with excellent accuracy and zero maintenance over
the life of the machine.

A number of good simulation tools exist that can help significantly reduce design time. Physical systems can aid the simulation process but they can take a significant amount of time, space and experimentation. A physical breadboard is also subject to materials delays, internal staffing issues and capital expenditure limits. This is not to suggest that a breadboard should necessarily be avoided, as it can serve as the basis for determining whether a system is worthy of investment beyond the brainstorming stage without too much difficulty.

Use of simulation tools, such as VisSim from Visual Solutions or Motioneering and Model Q modeling software, let you vary the design to determine its viability and usability. Approximate force, torque, accelerations and frequencies can be analyzed prior to investing in material.

What not to overlook
When an upgrade is required due to obsolescence, there are some often over-looked performance issues that can make or break the project.

A brush-style moving coil rotary motor, for instance, may have longevity and power handling shortcomings, but its replacement can be wrought with obstacles too. It is not unheard of for applications to require velocity loop bandwidths in excess of three or four times the capability of standard digital servo amplifiers. Replacing one of these brush-style motors in a high performance application can still be done successfully.

Recent advancements in field programmable gate array technology allow digital servo amplifiers to achieve current loop bandwidths of 3 to 5 KHz. This high bandwidth enables a 1 KHz velocity loop or greater. The capabilities of such a system coupled with the right motors can achieve and even exceed that of earlier systems, while offering the wear and power handling advantages of brushless technology.

For example, in an electronic assembly machine at Universal Instruments, a component placement head needed to operate faster. This placement head is on the Radial Lead Inserter. The previous method of control was pneumatic, which limited the machine’s capabilities for several reasons including, but not limited to: environmental factors, compression time variances, valve actuation variation, and exhaust limitations.

To compensate for these variances, the old system used deceleration hydraulic shock absorbers, proportional cushioned air cylinders, intensifiers, and special exhaust reclassifying mufflers to remove atomized oil that could not be exhausted to the air.

In
this stamping press application the old method used a conventional
servomotor and gearbox coupled to the feed roll with a belt. The
Cartridge DDR™ mounts directly on the feed roll and eliminates the
gearbox, belts, pulleys, and mounting structure to hold it all
together. It was installed in less than 10 minutes. Accuracy went from
0.002 in. with the geared servo to 0.0005 in..

Changing to a servo system was not without challenge, but the use of a Danaher Motion special R-series motor met the application requirements without the need for shock absorbers, special valves, or other pneumatic parts. Since this machine was part of a sequence of operations, the consistency of move time and acceleration allowed other functions to initiate earlier, increasing the cycle rate as well. Life tests revealed other improvements. The lack of shock decreased the wear on some components, significantly increasing machine reliability and uptime. Set-up times for the

machine build were reduced. When evaluated in combination, the brushless motor and amplifier were more cost effective than the previous scheme.

This system was first modeled in VisSim which reduced the evaluation time. Prior to the simulation, no motor appeared to fit the application due to envelope constraints and performance needs. Using the model with a custom motor and standard amplifier, the application was deemed worthy of continuation. The result is the patented Radial Lead 8XT from Universal Instruments.

Danaher Motion
www.danahermotion.com

:: Design World ::

BEI launches new high-speed linear encoder line

Goleta, CA – The rugged LN linear encoder provides fast, accurate and repeatable position feedback for a wide range of motion control applications.  The LN, an inductive linear encoder, is not subject to the speed limits imposed on its optical counterparts.  The encoder’s sealed read head completely surrounds the scale, eliminating the risk of the critical gap between sensor and scale varying with speed.  With onboard digital signal processing (DSP) capability, the LN boasts traverse times of up to 20 meters per second.  According to BEI, this is twice the speed available from most glass or magnetic linear encoders.

Standard measuring resolutions of 0.5 µm to 10 µm are available.  Scale measuring lengths range from as small as 2 inches to as long as 36 feet.  The LN linear encoder operates between 5 and 28 VDC and is equipped with either line driver or open collector outputs.  Universal mounting adapters and a variety of standard electrical interfaces make them easy to integrate into your control system.

BEI Industrial Encoder (IED) is an operation of Custom Sensors & Technologies (CST). IED manufactures optical encoders and associated electronics for the industrial market. IED is the market-leading brand of encoders in North America. CST is a division of Schneider Electric. CST was formed from the combination of BEI Technologies, Kavlico and Crouzet.  CST provides sensors, controls and actuation products to the industrial, transportation and military/aerospace markets.

About Schneider Electric
Schneider Electric is the world’s power and control specialist. Through its world-class brands, Merlin Gerin, Square D and Telemecanique, Schneider Electric anticipates and satisfies its customers’ requirements in the residential, building, industry and energy and infrastructure markets. With 88,670 employees and operations in 130 countries, Schneider Electric generated sales of €11.7 billion in 2005 through 13,000 distributor outlets.

For more information on any of BEI’s products, contact:
Scott Orlosky, Sales and Marketing Manager

BEI – Industrial Encoder
Custom Sensors & Technologies
7230 Hollister Avenue
Goleta, CA 93117
Tel : 800-350-2727 x240
Fax: 805-968-3154
Web: www.beiied.com
e-mail: sorlosky@beiied.com

SICK STEGMANN Goes 3D

DAYTON, OH – SICK STEGMANN, INC. has created a comprehensive and interactive online catalog of 2D and 3D configurable product models using SolidWorks 3D PartStream.NET®.  This new functionality allows customers, regardless of their design format, to configure, view and download 2D and 3D CAD drawings directly into their designs to check for fit and function.  This promises to significantly reduce product search and configuration times for improved time to market.

“There is an ever-increasing demand for better, faster, more flexible machines, and we are delighted to offer this service to our customers to help them satisfy the demands of their customers,” says Scott Hewitt, President of SICK STEGMANN, INC.

SolidWorks product models are available for SICK|STEGMANN’s complete family of absolute and incremental encoders, length measuring systems and motor feedback systems.

About SICK STEGMANN, INC.
SICK STEGMANN, INC. is a wholly owned subsidiary of SICK AG in Waldkirch, Germany.  SICK|STEGMANN is a world leader in the design and manufacture of incremental, absolute and linear encoders, as well as motor feedback systems.

SICK STEGMANN, INC., 7496 Webster Street, Dayton, OH 45413; (800) 811-9110; (937) 454-1956; fax: (937) 454-1955; email: sales@stegmann.com; or visit www.stegmann.com.

:: Design World ::

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