# Three-dimensional runout characterisation for rotationally symmetric components

## TL;DR

This paper introduces a new method for accurately measuring 3D runout in rotationally symmetric components using virtual instrumentation.

## Contribution

A novel 3D runout characterization method compatible with existing standards is proposed.

## Key findings

- The method uses four standard profile measurements to generate a 3D runout vector.
- An evaluation technique quantifies instrument errors independently from input deviations.

## Abstract

Rotationally symmetric components (such as gears and axels) are ubiquitous to modern devices, and their precision manufacture is necessary to keep costs and manufacture time down, as well as reduce waste and possibly hazardous component failure. The manufacturing errors, which affect the shape in the rotation axis, are grouped together into the common term “runout". Here we present a potential updated standard for characterising the runout of rotationally symmetric machined parts in three-dimensions, and evaluated using virtual instrumentation, enabling an accurate characterisation of the three dimensional (3D) surface deformation of a part from minimal surface information. For any 3D characterisation method to be widely adopted by the science, technology, engineering, and mathematics community, it must be fully compatible with previous methods and standards. As such, the proposed method produces a 3D runout vector based on four standard profile measurements. To evaluate the efficacy of the proposed runout method, a technique for evaluating the errors of commonly used virtual instruments has been developed. This evaluation technique produces a single-valued quantification of the deviation of the instrument outputs compared to the input parameters, decoupled from the errors on the instrument itself.