Linear Digital Measuring Device for Long Lengths

Product Announcement from Specialty Motions, Inc.

Linear Digital Measuring Device for Long Lengths-Image

Specialty Motions, Inc. Introduces a Versatile, Accurate Linear Digital Measuring Device for Long Lengths -

  • Allows users to measure up to 35’ in length accurately and easily using machine tool quality parts and technology.
  • Acts like a large linear caliper with a versatile digital readout.
  • High Accuracy - to the 4th DECIMAL

Specialty Motions, Inc. (SMI) a leading manufacturer of linear actuators and linear motion systems, has developed a simple but elegant method for measuring long-length materials such as linear shafting, carbon fiber tubing, wire cables or long sheets of wood, metal, cording or plastic in a variety of diameters and shapes.  In Its standard form, the Linear Digital Measuring Device (LDMD) can be made as a single piece unit to measure materials, in any increment, up to lengths of 136” and is consistently accurate within .003”.  The LDMD can be ordered in longer sizes as a joined rail system and single piece encoder up to 465” (38’) measurable lengths for custom needs.  It is simple to set up and simple to use.

A durable and rugged precision measuring tool, the LDMD operates on a highly efficient linear recirculating ball bushing bearing arrangement, where straight-line travel as well as pitch, roll and yaw are kept to a minimum to ensure accuracy within .003”.  The LDMD can be zeroed by sliding the carriage to the “home” position and touching a button on the digital readout (DRO).  The unit is now set at zero. To measure, slide the carriage away from “home” to allow the work piece into position then return the carriage, allowing the unique articulating tooling arm feature to make contact with the end of the work piece. The DRO gives you a length dimension in large, easy-to-read numbers to the fourth decimal place; much like a very large caliper at machine tool accuracy.

The DRO can be switched to display in inches or millimeters on the fly.  It is capable of absolute and/or incremental readings, allows for an offset for end of arm tooling adjustments and has linear and segmented error compensation capabilities. The DRO uses an RS232 connection method for data acquisition and remote PC features and printing. The DRO is expandable to accommodate multiple axis of motion if desired, such as to automate the optional MDS stand or rolling table.

“We took our knowledge of linear motion and combined it with our knowledge of encoding and created a machine tool quality measuring device” said Tom Corey, SMI President.  “The Linear Digital Measuring Device came from our own need to precisely measure long lengths easily, quickly and accurately on the shop floor, under harsh and varying conditions.  After looking at the market and finding nothing to meet our demanding needs, we created the LDMD to be easy to use, adaptable, rugged and reliable.”

The patent-pending LDMD is constructed using a proprietary extrusion for rigidity and consistent thermal expansion properties.   Simple mounting options allow it to be used horizontally, vertically, or laterally and can operate at high traverse speeds up to six feet per second without skipping count.  The IP67 rated encoder is fully submersible, shock-resistant and can be used in harsh environments.  The linear encoder is also designed to minimize the effects of thermal expansion and will grow linearly along with the extrusion to minimize twisting, bowing and distorting of other scales and systems.  The robust carriage and rail arrangement make it very durable and adaptable.

With no contact or wear items, LED’s or glass scales to break or burn out; the linear encoder requires no cleaning or maintenance and offers a long life.  An unlikely out-of-adjustment condition can be quickly resolved using gauge standards and/or laser positioning and adding error compensation adjustments.  Each linear encoder is serialized, and SMI offers traceability to ISO 10012-1 offering machine tool quality results.

Highly versatile, the LDMD comes with a unique quick change tooling arrangement featuring precision end plates, tooling pin locators, articulating tooling arms and V-block adapters and custom tooling.  It can be mounted on an optional rolling table or stand to allow for quick and easy setup from job to job.  The stand can be automated with lift tables and foot-pedal controls allowing adaptability for large and small diameter work pieces.

Linear measurement of long-length work pieces has never been easier or handled with greater precision.

About Specialty Motions, Inc

Established in 1990, Specialty Motions, Inc is a supplier of the factory automation components, devices and actuators as well as electro-mechanical assemblies for medical, optical, photonics, robotics and aerospace industries and equipment, among others.

Our linear actuators and linear motion systems include complete integrated automation devices engineered to OEM application needs and specifications.

For more information about the LDMD from SMI, please contact: or phone (951)735-8722 or visit us on the web at