MINISCALE PLUS is an optical incremental distance measuring system.

SCHNEEBERGER has released the MINISCALE PLUS optical incremental distance measuring system for designers who have to fit high-precision linear technology with integral distance measurement in small spaces.

Based on the MINIRAIL linear guideway system, the system combines guidance and measurement functionality in a highly integrated design. The compact miniature package also simplifies installation.

Measuring 9.2mm x 17mm x 16.1mm, nearly twelve of the smallest members of the MINISCALE PLUS range can fit in a single matchbox.

The small size results from integration of the measuring sensor in the carriage, which eliminates the need for additional installation space, as well as the cost of a separate distance measuring system.

MINISCALE PLUS has a measuring scale laser-marked on the guide rail and an optical sensor integrated into the carriage. A flexible circuit board connects the sensor to the interface module that handles signal processing.

MINISCALE PLUS meets client requirements for higher resolution and provides a choice between analogue and digital interface modules.

Structure and operation

The high-precision measuring scale forms part of the surface of the hardened rail and has a scale increment of 100µm.

A sensor illuminates the measuring scale and captures optical signals, which are conditioned by analogue or digital electronics in the interface module for subsequent processing.

Measurement takes place directly on the guideway, significantly reducing the risk of alignment errors. SCHNEEBERGER guarantees consistent accuracy due to vibration and shock immunity of the MINISCALE PLUS.

Locating the measuring scale directly on the rail reduces the need for analysis of thermal expansion and complex compensation routines in the related controller.

MINISCALE PLUS works reliably over an extended service life. The maximum acceleration of the tiny speedster is 300m/s² at a maximum speed of 5m/s.

The rail, carriage and balls are made from through-hardened, corrosion-resistant steel and ball re-circulators are made from POM.

Miniature guideways can be used at temperatures from -40 to 80°C, and have a cleanroom class rating of ISO:7 or ISO:6.

Maximum linearity deviation over a length of 1m is 10µm, with 5 µm also available on request. The repeatability is 0.1µm unidirectional and 0.2 µm bidirectional.

MINISCALE PLUS is delivered ready to install, and there is no need for additional components or machining for installation, which is required with glass scales.

Separate calibration of distance measurement is not necessary. Signals are available to the user on a 9-pin Sub-D connector, which enables users to choose their cable type for connection to the machine controller.

Highly diverse applications

The miniature measuring system is suitable for use in constrained spaces, which are often found in optical devices for medical technology.

For demanding applications requiring a defined preload or displacement force on the guideway, SCHNEEBERGER offers matched sets of carriage and rail.

Other custom adaptations, such as specific carriage heights or special lubricants, and a range of accessories are available. The MINISCALE PLUS option is available for the entire MINIRAIL range.