Research at the Precision Engineering Center
Part acceptance based on dimensional inspection by comparison to tolerance specifications is influenced by the static and dynamic errors in the inspection instrumentation, typically a Coordinate Measuring Machine (CMM). Traditional calibration artifacts are used to determine static influences due to machine geometry. The goal of this project was to design and fabricate a calibration artifact that will test a CMM both statically and dynamically. The artifact developed is a diamond turned, electroless nickel plated, 17-4PH stainless steel ring gauge (150 mm ID, 200 mm OD, 25 mm thickness). Sinusoidal features (5µm amplitude) were machined on the inside and outside diameter of the ring using a fast tool servo. The feature wavelength varies linearly along each surface between the longest wavelength (6.4 mm) and shortest wavelength (0.4 mm) without discontinuities. A reference flat was also machined on the ID and OD. The dynamics of a CMM under a specific set of measurement conditions can be found by computing a transfer function between a measurand of the ring gauge and the accepted “true” shape of the gauge. This allows an operator to devise a measurement strategy for a part that does not exceed the dynamic capabilities of the CMM and to predict the error in a measurement.
The following faculty, students, and PEC affiliates are involved in this project:
| Faculty | Students | Affiliates |
| Thomas A. Dow Alex Sohn Ken Garrard |
Karalyn Folkert | BWXT Y-12, LLC |
