• MMS Youtube
  • MMS Facebook
  • MMS Linkedin
  • MMS Twitter
5/3/2006 | 1 MINUTE READ

Laser Measurement Enables Closed-Loop Centerless Grinding

Facebook Share Icon LinkedIn Share Icon Twitter Share Icon Share by EMail icon Print Icon

This laser measurement system not only measures ground part diameters, but can also signal a grinder's control to make process adjustments on the fly.


Facebook Share Icon LinkedIn Share Icon Twitter Share Icon Share by EMail icon Print Icon

Routine part measurement adds no value to workpieces. It does, however, offer a means to track machining accuracy so that equipment can be adjusted to ensure that parts are produced to tolerance. If a process could adjust itself on the fly, then it would be unnecessary to interrupt production to make such adjustments manually. According to Freedom Technologies, headquartered in East Glastonbury, Connecticut, such a closed-loop centerless grinding process is possible with its Grindline laser measurement system.

The Grindline system allows non-contact laser measurement of ground part diameters ranging from 0.004 to 3.15 inches to 1-micron accuracy. Based upon that measurement data, the system’s software can then signal the grinder’s control to make the necessary adjustments (such as re-positioning wheels as they wear) in real time.

The system can be used with both through-feed and plunge-type centerless grinders. Its main components include a parts conveyor, part cleaning fixture, laser micrometer and dedicated controller. The conveyor receives parts as they exit the centerless grinder and transports them to the cleaning fixture. This fixture uses compressed air to clean parts prior to laser measurement. After cleaning, the conveyor delivers the parts to the laser micrometer to measure their diameters as they pass in front of the beam.

For each new job, users enter a nominal diameter, tolerance control band and out-of-spec tolerance limits. The control band is a safe range within the out-of-spec tolerance limits that allows shops to perform trending analysis. Users can specify the number of times the measured part diameter is permitted to fall outside the control band before the software signals the machine to make the necessary adjustments.

Users can also set up discrete measurement zones to find localized errors that may be caused by a chipped wheel or other similar problem. For example, a 6-inch-long part could be divided into six individual measurement zones along its length. The Grindline software will average the diameter measurements for each zone, rather than over the entire part length, to catch the small error. The software can also determine overall shaft straightness, as well as generate a detailed statistical report for each job.

The Grindline T-Series is designed for through-feed centerless grinders in which parts will have only one nominal diameter. The P-Series can measure multiple diameters for parts ground on plunge-type centerless grinders. Both versions are self-calibrating and can automatically compensate for fluctuating environmental conditions.

Hand holding a crystal ball

We’d rather send you $15 than rely on our crystal ball…

It’s Capital Spending Survey season and the manufacturing industry is counting on you to participate! Odds are that you received our 5-minute Metalworking survey from Modern Machine Shop in your mail or email. Fill it out and we’ll email you $15 to exchange for your choice of gift card or charitable donation. Are you in the U.S. and not sure you received the survey? Contact us to access it.

Help us inform the industry and everybody benefits.


  • Creep-feed Grinding Is A Milling Process

    Because creep-feed grinding is essentially a milling process, why not use a VMC? A grinding machine supplier describes how a VMC platform can make creep-feed grinding more effective.

  • Double-Disc Grinding On The Move

    The double-disc grinding process is consolidating its position in automotive applications but is moving into other industries. Double-disc grinders are now easier to operate, and they have added capabilities for control flexibility, precision process control, faster changeovers, and grinding of nontraditional materials.

  • Centerless Grinding: Not Magic!

    Achieving consistent and quality results from the centerless grinding process requires an understanding of the basic fundamentals. Most application problems associated with centerless grinding derive from a misunderstanding of the basics. This article explains why the centerless process works and how to use it most effectively in your shop.