18,000 RPM Air Bearing Spindles for Image Scanning in Harsh Conditions

The Challenge

Design an inspection system for a European high-speed rail system – that must function accurately in harsh conditions while moving 75 mph.

The Design Solution

Custom Rail Air Bearing
Imaging Spindle

We designed a set of three high-speed air bearing spindles that were synchronized for the 3-dimensional image scanning and inline inspection. To inspect the track, switches, tunnels and bridges for potential maintenance issues, the system was mounted on a dedicated rail car traveling at 75 mph allowing the spindles to create a 3-D image of the rail every 10 cm (less than 4″).

To achieve the necessary rotational speeds of 18,000 rpm, the design incorporated individual direct drive brushless DC servo motors and encoders on each of the ultra-precision air bearing spindles. To simulate the most extreme conditions, each spindle was tested, including vibration testing to 10 G’s, after being stored in a freezer overnight and then run at 180°F continuously for over 8 hours.

System Feature Summary

  • Synchronized ultra-precision air bearing spindles
    • Aluminum construction for low inertia
    • Individual direct drive brushless DC servo motors
    • High resolution rotary encoders
    • 50 mm clear apertures through the spindles
    • 45° fold mirrors
  • Vibration isolation platform
  • Multi-axis controller
  • Capacitance probe monitoring system


Thank you for your interest in ABTech’s ultra-precision measurement tools and services.
Please tell us a little about what you need to accomplish and we will be in touch to discuss any of the additional details that will help you choose your best option.

Thanks a lot for your help. Your rapid, informative correspondence was invaluable. Hopefully I won't be bothering you with any further questions, but it's good to know you're willing. (following remote technical support provided for system installed at the South Pole) Morgan HedgesPost-doctoral Research Associate
Princeton University
Made in the U.S.A of U.S. and imported parts

Every product we sell exemplifies our company-wide commitment to "Pride in Precision" craftsmanship. To that end, all of our products are designed, manufactured, and tested exclusively by ABTech at our New Hampshire facility.

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