Join ASPE

<<Back

Tutorial – Precision Metrology of Rotary Axes

Grigg 132
8:00 AM – 12:00 Noon

Dr. Eric Marsh (KLA)
Dr. Ir. Henny Spaan (IBS Precision Engineering)
Dr. Byron Knapp (Professional Instruments Company)
Dr. Jimmie Miller (UNC-Charlotte)

This tutorial covers the fundamental concepts of measuring spindle motion: 1) explanations and examples of the error motion, stiffness, and thermal growth of precision spindles; 2) terminology for defining the behavior of spindles used in instruments, measuring machines, machine tools, and rotating equipment of all kinds; 3) instrumentation available for measuring the various parameters of spindle performance; and 4) hardware demonstrations of spindle measurements and data analysis.

Measurement of multi-axis machining center rotary tables is a special topic covered this year. The tutorial will provide an understanding and application of fundamental metrology principles specific to the testing and improvement of 5-axis machine tool accuracy. Issues related to multi-axis metrology will be explained in detail with a focus on three types of measurements: 1) machine acceptance (ISO 10791-6); 2) rotary table position and compensation; and 3) dynamic analysis.

The tutorial includes hardware and software demonstrations of spindle metrology systems. Key course concepts will be shown on actual precision bearings.


Dr. Eric Marsh received his doctoral degree from the Massachusetts Institute of Technology for his work with Professor Alexander Slocum’s Precision Engineering Group. His graduate research focused on reducing vibration in semiconductor process equipment and machine tools. Until his retirement from Penn State University in 2022, Eric worked with an amazing group of young engineers within the multidisciplinary field of precision engineering. Their primary focus was on spindle metrology, ball bearing metrology, and spindle-based instrumentation for monitoring diamond turning and precision grinding. These three research areas share the common theme of accurate measurement of an axis of rotation. Their investigations involved many different issues associated with spindles, including sensors, data acquisition, signal processing, structural design, and dynamics. Their work showed spindle error measurement repeatability of better than 0.2 nm on ultraprecision air bearing spindles. In 2022, Eric began a second career at KLA, makers of semiconductor process monitoring tools.


© Minneboo Fotografie Nicole Minneboo

Dr. Ir. Henny Spaan is founding president & CEO of IBS Precision Engineering; a Dutch company which works with companies and research institutes world-wide to enable the manufacture of leading edge products or instruments where ultra-precision is critical. As experts in metrology (the science of measurement) IBS delivers technology solutions for ultra-precision measurement, motion control or applications demanding the ultimate in geometrical accuracy.

In 1990, Henny graduated from Eindhoven University in the Mechanical Engineering department. He obtained his PhD in 1995 in the Precision Engineering Group of Prof. Peter Schellekens on Machine Tool Software Error Compensation. Henny started his engineering company in 1993 whilst completing his PhD.

He holds several patents on machine tool error calibration and compensation techniques; air-bearings and metrology on ultra-precision machines. He has led multiple EU and national funded projects and is active in standardization within ISO (TC213: Metrology). As a member of CIRP, ASPE and EUSPEN (since its founding year), he is a former Board member of ASPE and was euspen President from 2009-2011. And he is currently serving on the VDMA – EMINT board.

In 2013 he received the Rien Koster Award for his significant contribution to the field of mechatronics and precision technology in the Netherlands.


Dr. Byron Knapp has over twenty years of experience in the design and development of precision manufacturing systems and precision machine design. He received his BS, MS and PhD degrees in Mechanical Engineering at The Pennsylvania State University under Professor Eric R. Marsh. Byron has been a Senior Engineer at Professional Instruments Company for 15 years where his focus has been on air bearing spindle characterization using finite element and modal analysis, nanometer-level spindle metrology, and occasional forays into oil hydrostatic spindle testing. Byron is an active member of the international precision engineering communities of ASPE and euspen.


Dr. Jimmie Miller received his doctoral degree in (nano/precision) engineering from the University of Warwick UK under the primary direction of Dr. Robert Hocken (UNC Charlotte) along with Dr. Stuart Smith (UW) and Dr. Keith Bowen (UW). He has worked full-time since 1993 as a Research Engineer at the University of North Carolina at Charlotte, including roles as the Chief Engineer and Deputy Director of the Center for Precision Metrology. He holds four patents in manufacturing/metrology. He also teaches a graduate class in machine tool metrology, which includes a hands-on practicum that can be taken remotely in conjunction with a four-course graduate certificate series. He also holds degrees in Electronics Engineering (AAS), Math (BS), Physics (BS) and Microelectronics (MES). Jimmie has been involved with ASPE since 1990, serving on the ASPE Board from 2016-2018. He is a regular reviewer for the Precision Engineering Journal. He also authored the chapter entitled Metrology in the book Basics of Precision Engineering (2018)