Experimental Study of the Volumetric Error Effect on the Resulting Working Accuracy—Roundness

Abstract

Currently, various types of software compensations are applied to machine tools. Their aim is to increase the working accuracy of the tools. The improvement in working accuracy is then further assessed according to the increase in the dimensional and shape accuracy or the surface quality of the workpiece. This publication describes the effects of the volumetric accuracy of a machine tool on the working accuracy of a workpiece, where total roundness (RONt) is evaluated in multiple cuts. In the experiment, two test workpieces are manufactured on a three-axis milling machining centre. The first is made using a standard machine setup while the second with activated volumetric compensation. The LaserTRACER self-tracking laser interferometer is used to compensate for volumetric accuracy. In the second part, verification measurements are performed with a Ballbar, where roundness error is evaluated according to ISO 230-4. Then two test workpieces are machined, and, in the last part, measurement is performed on Talyrond 595S roundness measuring equipment. Finally, the results are analysed and the dependence between the volumetric accuracy, the circularity error of the machine and the working accuracy of the CNC machine tool is established, represented by the RONt of the workpiece. This paper presents new and unpublished relations between the volumetric accuracy of the machine tool and the RONt of the workpiece.

Geometric Error-Based Multi-Source Error Identification and Compensation Strategy for Five-Axis Side Milling

“…However, unlike this study, the object equipment they studied was a small three-axis machine tool, and they considered less types of errors than this study. In comparison with their study, Similar to the present study, Holub, M. et al described a new, complex approach for verifying the dependence between the geometric, volumetric, and working accuracy of CNC machine tools in 2020 [20]. In their research, an improvement in the volumetric accuracy of a small three-axis machine tool by 70% resulted in an up to 58% improvement in circularity in an unloaded state, measured according to ISO 230-4, and a 40% improvement in the RONt of the workpiece under the finishing conditions of machining.…”

Possibilities of a Hybrid Method for a Time-Scale-Frequency Analysis in the Aspect of Identifying Surface Topography Irregularities

“…It is a precise measurement system; the operating principle of which is based on the method of measuring changes in the radius (radial method) with a rotary table. Talyrond 365 is commonly used in the bearing industry to analyze the quality of production of cylindrical elements [ 50 , 51 ]. On the other hand, the deviation of roundness and waviness of bearing rollers is of key significance, since its excess values cause the generation of additional vibrations of the rolling bearings.…”

Optimizing dynamic measurement accuracy for machine tools and industrial robots with unscented Kalman filter and particle swarm optimization methods

“…The telescoping ballbar, first proposed and patented by Bryan in 1982 [3], revolutionized the measurement of radial changes in circular motion using an accurate linear scale sensor. Since their introduction, ballbars have been extensively applied in circular tests [4,5], calibration of rotary axes [6,7], assessment of the thermal or geometrical behavior of five-axis machine tools [8,9], kinematic calibration of parallel kinematic machines [10], and industrial robots [11]. As an efficient automated tool conforming to ISO 230-4 standards, the telescoping ballbar excels in error detection in machine tools and industrial robots, ensuring precise error identification [12].…”