Choosing a shaft for a traditional linear ball bushing is relatively easy — choose the appropriate diameter, material, and hardness, check the dimensional accuracies and tolerances, and if the shaft is unsupported, perform a beam deflection calculation. But because spline shafts can withstand both radial and torque loads, it’s important to ensure the shaft strength […]
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How to calculate bearing life for a ball spline
A ball spline is much like a linear ball bushing and shaft, but with axial grooves along the outer diameter of the shaft and the inner diameter of the nut. These grooves prevent rotation of the bearing (referred to as a spline nut) and allow the ball spline to transmit torque. Because a ball […]
What is stepper motor resonance and how can it be avoided?
The discrete, step-by-step movements that give a stepper motor its accurate positioning capability can also lead to some undesirable performance characteristics — namely, vibration and audible noise due to resonance. Stepper motors naturally exhibit small vibrations with each step, due to the inertia of the moving rotor, which causes the motor to slightly overshoot (or, […]
New ball screw selection tool streamlines online product selection
Thomson Industries, Inc., has launched a new online selector tool that simplifies and streamlines the purchasing experience for its precision ball screws. The tool helps design engineers zero in on the right part quickly, access a 3D model with just a click, view pricing and lead times, easily share orderable product specifications and take advantage […]
Nanopositioning controller for piezo stages boasts 270-W peak power, nanometer-level precision
A high-power version of PI’s (Physik Instrumente) E-727 family of multi-axis piezo nanopositioning controllers provides 270 W of peak power – close to 10X of the standard version. The enhanced performance is useful for dynamic, nanometer-level precision motion and positioning applications, such as FSM (fast steering mirrors) in free space optical communication and laser material […]
What are the differences between incremental and sine-cosine encoders?
Encoders that provide incremental position measurements (whether rotary or linear) output two signals, or channels, typically termed “A” and “B,” to provide position and direction information. These output signals can be in the form of analog sine and cosine waves or in the form of digital square waves. Those that produce digital output signals are typically […]
Linear actuators automate shampoo-bottle filling with less drips
Consider the equipment that fills shampoo bottles. Such filling machines use conveyors to transport empty bottles to sensor-tracked wait positions. Then they insert shampoo-dispensing nozzles into the bottles and slowly raise those nozzles as the liquid rises during dispensing. Holding a constant distance between the nozzle ends and liquid surfaces prevents the shampoo from foaming. […]
Industrial gas springs help in fight against COVID-19
Gas springs, also called gas dampers, tension springs, gas-pressure springs depending on the setup and context, are compressed-air or oil cylinders that install in motion designs to damp forces and return kinematic linkages and more complicated assemblies to default positions. Gas springs work through a piston on the end of a rod that protrudes from […]
How to calculate linear ball bushing life (and how it differs from other life calculations)
The standard life calculation for linear ball bearings is widely known as: L = bearing life (m) C = rated dynamic load (N) F = applied dynamic load (N) But linear ball bushings often experience operating conditions that aren’t accounted for in the general bearing life equation. To account for these adverse conditions, the life calculation […]
Round-rail linear guide or profile-rail linear guide?
In this article, we outline how to choose a linear guide for your application and environment. By Lindsey Brimage and Eric Schultz | Thomson Industries Ian Miller | Motion Industries Canada Designers of linear motion systems often find themselves weighing the pros and cons of round versus profile (also known as square) linear guides. Many […]
