What is a Linear Stage Device?
A linear stage or translation stage is a component of a precise motion system used to restrict an object to a single axis of motion. The term linear slide is often used interchangeably with "linear stage", though technically "linear slide" refers to a linear motion bearing, which is only a component of a linear stage. All linear stages consist of a platform and a base, joined by some form of guide or linear bearing in such a way that the platform is restricted to linear motion with respect to the base. In common usage, the term linear stage may or may not also include the mechanism by which the position of the platform is controlled relative to the base.
It’s a positioning device that increases high-precision motion while decreasing runout. More simply, this stage is used to restrict an object to a single axis of motion. The level of precision a linear stage provides is crucial in industrial and scientific operations, from photonics instrumentation to semiconductor manufacturing. Your options when it comes to selecting a linear stage range from more cost-effective products to more complex, high-performance models with air-bearing capabilities.
How Does a Linear Motion Device Works?
Typically, objects can rotate along any of three axes, giving the object six degrees of freedom: three rotational and three translational. The linear stage restricts five of these axes, allowing the object to move on only one translational axis. When used properly, the linear stage provides a superior finished product quickly and efficiently.
The stage is comprised of a platform and base that are conjoined by a guide or linear bearing. This joining restricts the platform to linear motion. A linear stage also commonly utilizes a stepper motor. A stepper motor is a brushless, synchronous electric motor that can convert digital pulses into mechanical shaft rotations. A lead screw or worm gear drive are often accompanied by a stepping motor to further linear motion control. For best results, a step motor can be used in conjunction with a stepping motor driver in micro step mode.
Guide types
Linear stages consist of a platform that moves relative to a base. The platform and base are joined by some form of guide which restricts the motion of the platform to only one dimension. A variety of different styles of guides are used, each with benefits and drawbacks making each guide type more appropriate for some applications than for others.
What is Linear Stage Device Made For?
Manual linear translation stages are designed to provide precise, high-resolution travel over any combination of the three linear degrees of freedom. More importantly, however, they constrain any form of movement in the other angular or linear degrees of freedom: pitch, yaw, roll, as well as x-, y-, or z-axis translation. They are frequently used in applications such as microscopy, metrology, optical fibre alignment, optical delay lines, interferometry, or wherever exact linear position is required. Industries that utilize linear stages include research, bio-medical, life sciences, astronomy, metrology, semiconductor, and more.
Rollers
- Benefits
- Inexpensive.
- Drawbacks
- low load capacity, poor accuracy, short lifetime.
- Applications
- Optics lab stages, drawer slides.
Cylindrical sleeve
- Benefits
- High load capacity, unlimited travel, inexpensive.
- Drawbacks
- Susceptible to binding if bending moments are present.
- Applications
- Radial arm saws, scanners, printers.
Flexure
- Benefits
- Excellent accuracy, no backlash, no wear (infinite lifetime).
- Drawbacks
- Short travel (limited by flexure range), low load capacity, expensive.
- Applications
- Optic fibre alignment.
Recirculating ball bearing
- Benefits
- Unlimited travel, relatively inexpensive.
- Drawbacks
- Low load capacity, quick to wear, oscillating positioning load as bearings recirculate.
Dovetail
- Benefits
- Highest load capacity, unlimited travel, long lifetime, inexpensive.
- Drawbacks
- High positioning force required, susceptible to binding if bending moments are present, high backlash.
- Applications
- Machine shop equipment (ex. mill and lathe tables).
