FAQ: What are recirculating linear bearings?

Linear ball and roller bearings can be broadly divided into two categories—recirculating and non-recirculating—depending on whether or not the rolling elements actually flow (or circulate) through the bearing housing. In order to understand what a recirculating linear bearing is, let’s first take a look at bearings that don’t recirculate. Non-recirculating linear bearings Non-recirculating bearings have […]

Linear Motion Tips

7 Twitter accounts that make science fun!

It’s probably safe to say that those of you who follow this site (myself included) are science geeks. Whether it’s archaeology, astronomy, or biology, we’re fascinated by the latest discoveries across all realms of science and technology. And for staying on top of these developments, there’s no better platform than Twitter. Most leading scientists and […]

Linear Motion Tips

ETEL expands linear motor lLine

As engineers expand their range of machines to a point where a larger payload is required, an upgrade of their linear motors may be necessary. So, to make their design process easier, ETEL has added extra ironcore linear motor lengths to each of their different widths. These new lengths are compatible with existing 50, 70, […]

Linear Motion Tips

Servo motor or stepper motor? How to choose

The overwhelming majority of linear motion applications (with the exception of pneumatically-driven types) use either a stepper motor or a servo motor to provide torque to the driving mechanism, which is typically a ball or lead screw, rack and pinion, or belt and pulley system. And unlike other components involved in linear motion, when choosing a motor, […]

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Linear actuators: belt driven vs. rack and pinion driven

Belts and rack and pinions have several common benefits for linear motion applications. They’re both well-established drive mechanisms in linear actuators, providing high-speed travel over extremely long lengths. And both are frequently used in large gantry systems for material handling, machining, welding and assembly, especially in the automotive, machine tool, and packaging industries. Timing belts for linear […]

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New Profile Rail Linear Recirculating Bearings from Lintech

Lintech’s MR, ARC, and HRC Profile Rail Linear Recirculating Bearings incorporate two or four rows of recirculating balls arranged in a 45 degree contact angle with the raceway. The rigidity under moment and torsional loads is increased by this design. Larger ball size is used to enhance the load capabilities. This design offers equal loading in all […]

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How to estimate your linear actuator needs with minimal application data

Choosing linear motion components during the development phase of a project has been a source of frustration for designers and application engineers for decades—especially when it comes to complex subassemblies such as linear actuators. Consider for a moment the influence that a linear actuator has on the overall machine design. First of all, in an actuator, […]

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When do you need a ball screw?

The gap is narrowing between applications that require ball screws and those that are suitable for lead screws, and it’s becoming more difficult for engineers and designers to determine which technology is best for their machine. Advances in lead screw designs and materials have given them higher load capacities and better positioning accuracy, making them a sound choice […]

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The top 5.5 linear motion stories of 2016

As a writer and editor, it’s always fun (and sometimes surprising) to look back at the end of the year and see what articles our readers were most interested in. And for you, our readers, it offers the chance to take a quick look at what are, at least to some of your peers, important topics […]

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When is static load capacity important?

When sizing a recirculating bearing, most designers and engineers focus on bearing life, which is based on dynamic load capacity. This is the load at which a linear recirculating bearing will, with 90 percent certainty, achieve the targeted service life before fatigue occurs. Static load capacity, on the other hand, is the force that causes permanent […]

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How to choose linear guide accuracy

When choosing a recirculating linear guide, there are several criteria that need to be specified, including size, preload and accuracy. And although the term “accuracy” is often used in a generic sense, when referring to recirculating ball or roller guides, it designates five characteristics: Height tolerance of the rail and block assembly Permissible difference in height between […]

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New multi-axis positioning family from PI

High-end industrial and research applications rely on precision motion stages and systems to execute mission-critical procedures and processes. PI, a leading provider of nanopositioning and motion control solutions, has developed its new family of linear, rotary, and Z-axis stages to meet those demanding requirements. Meet the L-310 vertical stage, the L-611 rotary stage, and the […]

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FoodStream Pillow and Flange Blocks: FDA/USDA and 3A-Dairy Compliant

FoodStream electroless nickel plated pillow and flange blocks from LM76 are FDA/USDA/3A-Dairy compliant linear motion components. They complement LM76’s line of FDA compliant bearings, scraper seals, and shafting. FoodStream off-the-shelf pillow and flange blocks are ideal for use in processing and packaging food, producing pharmaceuticals, the BioPharma industry, and in medical devices. Inch size FoodStream […]

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How to choose linear guide preload

When choosing a recirculating linear guide, one of the key criteria in the specification is preload. Linear guide preload eliminates the clearance between the bearing block and the rail, which increases rigidity and reduces deflection when external loads are applied. To achieve preload, manufacturers use balls (or rollers, in the case of roller bearings) whose diameter is […]

Linear Motion Tips

FAQ: What is stick-slip?

Stick-slip, also referred to as “stiction,” is the bane of engineers and machine builders who need smooth, precise motion. Simply put, it’s the jerkiness that can plague both plain and recirculating linear bearings when they transition from standstill to motion. Here’s why stick-slip happens… When two objects slide against each other, friction works against their motion. […]

Linear Motion Tips

The good old days…they were terrible!

That was the mantra of my Technology and Society professor in college. And in many cases, I have to agree with him. While we like to romanticize the “good old days,” when things were simpler and more straightforward, how many of us would really want to go back and work in the era of slide rules […]

Linear Motion Tips

Drive nut runs on threaded shaft

Amacoil-Uhing model RS drive nuts provide smooth backlash-free linear motion in machine design. Unlike a screw, the RS drive nut runs on a smooth shaft. This eliminates the potential for debris to become trapped in threads which could then clog or jam. If material does fall onto the shaft, it is easily removed by wiping the […]

Linear Motion Tips

Linear actuators: the make vs. buy decision

With the range of linear actuators on the market, it’s becoming easier for machine builders and end users to find a standard or “customized standard” product that meets even the most unique application requirements. But there are still times when it makes sense, from a financial or technical standpoint, to design and build an actuator […]

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What is a PV rating?

When discussing bearing life, what comes to mind for most engineers is the standard L10 bearing life equation. But this equation was developed for bearings with rolling balls. (A similar equation exists for bearings that use rollers rather than balls.) For plain bearings, which have no rolling elements, determining the suitability of the bearing for a […]

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Guide systems that turn corners

The shortest distance between two points may be a straight line, but some applications dictate moving in curved sections and around corners. When two or more axes are combined, as in a Cartesian or gantry system, a method of control called contouring can be used to create radii and round the corners of traditional rectilinear coordinates. […]

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How to shrink the size of a linear actuator

Linear actuators come in a wide range of sizes, but over the past several yeas, manufacturers have been emphasizing more and more compact footprints. But no matter how small the actuator, the addition of a motor can make the overall size of the complete system too large for space-constrained applications. Some manufacturers are addressing this issue […]

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New Air Spring product line for demanding industrial applications

ITT Inc. announced today that it is introducing a new Compact Automation and Turn-Act Air Springs product line that provides air actuation for linear motion control. These highly durable, air-tight pneumatic actuators are the ideal solution for demanding industrial applications, including the pulp and paper, lumber mill and automotive assembly industries. With products designed for fast and affordable ease of repair, […]

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Can stack linear actuator provides exceptional performance

Portescap introduces the next generation of high power density Can Stack Linear Actuators, the 20DBM. These 20 mm linear stepper motors offer an optimized design ideal for applications demanding high linear force. The new 20DBM features an optimized magnetic circuit which provides improved performance over existing designs The 7.5 degree step angle provides finer incremental […]

Linear Motion Tips

Linear systems for nanopositioning

When we talk about linear motion, we typically discuss applications where the travel distance is at least a few hundred millimeters, and the required positioning is in the range of a few tenths of a millimeter. And for these requirements, guides and drives with recirculating bearings are a good fit. Case in point, the lead […]

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The world’s largest gantry robots

Gantry robots, by design, tend to be large systems, capable of moving hundreds or thousands of pounds over long distances. Characterized by having two base axes for extremely high load capacity and rigidity, the most common drive mechanisms for gantry systems are belts, rack and pinion systems, and chains, with linear motors being used in special cases where […]

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