Precision agriculture is the discretization of farming — defined as the analysis of highly variable (and often unpredictable) landscapes to: • Break larger agricultural fields into smaller discrete sections • Quantify the characteristics (such as soil composition, light, and seed spacing) of each section • Adapt to the variations between sections with automated farm equipment […]
Track roller (cam + wheel) guides
What to consider when specifying a linear slide
Here are some considerations when specifying a linear slide for a new or existing application. By Mike Quinn • LM76 When a design engineer has fully defined a linear-motion application’s requirements regarding travel length, speed, force, and accuracy as well as repeatability, the next question to answer is this: Does an off-the-shelf linear slide (or […]
What are fixed and floating bearings in the context of linear motion?
There are two instances when the terms “fixed bearing” and “floating bearing” are used in linear motion: to describe the support bearings used on ball and lead screws, and to describe linear guides mounted in parallel. And while the meanings of the terms are the same in both situations, their applications are different in each […]
Mechanical properties of materials: stiffness and deflection
In a previous post, we looked at the stress-strain curve and its relationship to various aspects of material strength — tensile strength, yield strength, and fracture strength, for example. And while we often think of materials and structures in terms of strength, technically, “strength” is a measure of how much force a material can withstand […]
What is curvilinear motion and when is it used?
In single-axis motion systems, travel is typically either linear (in a straight line) or rotary (in a partial or complete circle). But some applications call for a system that combines straight sections of motion with curved sections — referred to as curvilinear motion. Curvilinear systems generally take one of two forms: simple, constant-radii sections (such as […]
What are Hertz contact stresses and how do they affect linear bearings?
Linear bearings that use balls or rollers to carry a load are subjected to Hertz contact stresses — a type of material stress that plays a significant role in determining the bearing’s load capacity and fatigue life. When two surfaces of different radii are in contact and a load is applied (even an extremely small load), […]
Basics of cam followers (including those for linear motion)
Cam followers are power-transmission devices with a rotary bearing core that bears load while serving as the interface between independently moving machine sections. Applications include those on rotary indexing tables and turntable conveyors, long-stroke robot transfer units (RTUs), and an array of highly customized machinery. The outer diameter (OD) of the cam-follower bearing assembly is […]
Motion Trends: Linear bearings help some CNC machine builders trim cost
Axes on CNC machines to allow spindle movements are mission critical — requiring high accuracy. But doors and other linear axes have different design requirements — with forgiveness and ruggedness being priority instead. Now, linear bearings from Rollon Corp. help some CNC machine builders trim cost and improve reliability by satisfying these unique design requirements. […]
Linear motion trends in slides: Robotics and mobile designs lead the charge
Demand for simple-to-install and pre-integrated linear-slide systems continues unabated … especially in applications only recently automated. Here’s the perspective of Matt Mowry, North American market manager for drylin products at igus: “We’ve supplied fully assembled and customized linear-slide tables … complete with motors and accessories. We’ve also supplied custom-extruded linear profiles and bearing liners to […]
Take the burden out of managing misalignment in linear motion systems
No one wants a linear bearing to fail prematurely. While many factors can threaten a bearing’s expected life, designers of industrial machines must especially guard against alignment errors between the bearing rails and moving elements. Not only is misalignment one of the most common causes of bearing failure, it is also among the most costly […]
