Gear sizes are typically specified by one of two designations: module or diametral pitch. While both specifications define the size of the gear teeth, module and diametral pitch are calculated differently, with module (sometimes referred to as metric pitch) being the metric sizing standard and diametrical pitch being the Imperial (inch) sizing method. Standard modules for […]
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Getting straight on roller screws
Knowing the differences between the several kinds of roller screws can help determine the best fit for an application. Michael Boudreau, P.Eng. Application Engineering Manager Rollvis S.A. Planetary roller screws – also referred to as satellite roller screws – have long been the primary choice for applications that involve heavier loads and higher forces than […]
Ball spline preload: How, why, and when it’s applied
Like other linear motion components where rolling elements ride in raceways, ball splines can be supplied with preload. In the case of a ball spline, the main purpose of preload is to reduce angular backlash — clearance in the rotational direction — when torque is applied. Without preload, ball splines have a small amount of […]
What’s the difference between moment and torque in linear motion applications?
In linear motion, we often deal with applications that involve forces applied at a distance from a linear guide — referred to as cantilevered, or moment, loads. In these cases, we’re concerned with guide’s moment load capacity, or its ability to resist rotating. But we also deal with components that should rotate when a force […]
Smart mechatronics add capabilities to linear motion applications
Today’s manufacturing system OEMs and automation end users are constantly seeking technology advancements to help make their lives easier. Industry 4.0 innovations have spurred a new class of smart technologies that combine digital electronics and communication interfaces for more sophistication, functionality, and ease of use. By Richard Hansen • Senior automation engineer | Bosch Rexroth […]
New direct-drive linear modules from PI
PI’s two new series of direct-drive linear modules are geared for machine builders and system integrators. The V-855 and V-857 product families were designed for high-load and high duty cycle industrial precision motion applications where traditional actuators or linear slides with lead-screw or timing-belt drives are not precise, robust or reliable enough. The maintenance-free and […]
What is ball screw whip and why does it happen?
Ball screws are often the drive mechanism of choice in applications that require high thrust forces with excellent positioning accuracy and repeatability. But one of the drawbacks of ball screw technology is that speed is inversely related to length — the longer the ball screw shaft, the more likely it is to whip, like a […]
What is a 7th axis (also known as an RTU) and when is it used?
Linear Cartesian and gantry robots are used extensively in automation, particularly for tasks such as pick and place and assembly. But for applications that require movements such as changing the orientation of a part or navigating around complex obstacles, the robot of choice is often the 6-axis articulated robot. Despite their dexterity, the reach of a […]
Linear slide with maintenance-free voice coil motor features nanometer precision
PI extends its large offering of nanometer precise, fast focusing stages with the addition of its new V-308 nanopositioning slide for vertical applications providing 7 mm of Z-travel and 10 nm incremental motion, making it suitable for OEM and research applications in the life science, semiconductor, and material science fields. The novel design combines long […]
When does open-loop stepper control still make sense?
Stepper motors are inherently open-loop devices, able to make precise moves without feedback regarding motor position. But one of the drawbacks of using stepper motors in some applications is that if steps are lost (or gained), the system has no way to detect this. The resulting discrepancy between the actual position of the motor and […]
