Thursday, 05 February 2015 15:34

New Sealed Linear Actuators For Lighter Loads

Our SLS sealed linear stages have just become more versatile with the introduction of a compact model intended for lighter loads.

The SLS Light measures just 80 x 120-mm, or 60-mm less than our SLS Medium model. The Light version has maximum dynamic payloads of 15 kg for the direct drive linear motor variation and 30 kg for the ball screw version—versus 30 and 100 kg for the comparable SLS Medium models.

Integrated Lip Seal. Both sizes of SLS sealed linear stages feature a proprietary linear lip seal design that integrates seamlessly with the stage’s anodized aluminum housing. Made from a ruggedized polyurethane elastomer, the seal resists chemicals, temperature extremes and mechanical wear. The seal can also be replaced in minutes without the disassembling the stage—or even removing the payload in most cases.

Linear Actuator Performance. As you might expect, SLS Light has lower continuous force capabilities and maximum load capacity than the beefier Medium models. For example, SLS Light offers continuous linear forces of up to 120 N in the linear motor version, while the SLS Medium provides up to 300 N. Ballscrew continuous linear forces are same for both SLS Light and Medium at 1400 N.


Other than the differences in dimensions, payload and continuous forces, SLS Light sealed stages perform very much like the SLS Medium models:

  • Speed reach 4 m/ second for linear motor models. Ballscrew models can achieve 0.2 m/s with a 10-mm lead, which is slightly slower than the Medium’s 0.5 m/s maximum.
  • Accuracy is just ±2.0 μm in the linear motor version and ±4.0 μm in the ballscrew version.
  • Bi-directional repeatability is ±0.5μm and ±1.0μm for the linear motor and ballscrew versions, respectively.

Many Uses. Applications for the SLS Light Sealed Linear Stage include any application in which contaminants can threaten the smooth operation of a linear actuator. These applications include laser machining, welding, semiconductor and machining.

For more information on SLS sealed linear stages, visit






Published in Bell-Everman News
Wednesday, 04 February 2015 16:08

Simple Linear Stage Features New Drive Mechanism

If you find that direct drive or ballscrew-driven positioning stages are overkill for your application, you now have a simpler option. Our new ServoSpline™ positioning stages feature a unique drive mechanism that provides backlash-free motion and simplified control.

Modern rack-and-pinion. ServoSpline represents a rethinking and extension of a classic rack-and-pinion design.  In this case, there are two sets of elastomeric racks located on the four underside edges of the stage’s moving platform. The pinion consists of perpendicular, direct-driven helical splines the extend under the full length of the platform. Attached directly to ServoSpline’s motors, these steel splines are vertically offset so that one meshes with the rack in the x-axis and the other in the y-axis. Simple motion commands can position the stage in x- and y-axis by independently driving the two splines.

Technical advantages. ServoSpline is not intended to replace high-fidelity stages in applications with the most stringent requirements for accuracy, repeatability. Nor is it meant for heavily loaded applications. Instead it comes into play when you need a reliable stage that easy to deploy. ServoSpline’s technical features include:

  • No backlash. ServoSpline’s urethane elastomer rack offers a bit of compliance and very closely conforms to the shape of the helical spline. This tight fit and small amount of “give” eliminate backlash altogether.
  • Long wearing. The urethane elastomer used in the rack has been formulated for its wear properties. What’s more, only a small portion of the rack comes in contact with the steel splines at any given stage position, which further minimizes wear potential.
  • Easy to implement. The motor driven crossed splines can deliver the stage to any x-y coordinate with very simple motion commands. ServoSpline also follows our embedded motion system philosophy, so you can basically just bolt it onto your machine and expect it to run.

Applications. We’ve already applied ServoSpline to 3D printing and automated assembly applications as well as dispensing, engraving, additive manufacturing, biomedical titer plate indexing and pipetting for diagnostic equipment, but it can serve in a wide variety of machines that need motion stages that are easy to implement.




Published in Bell-Everman News