On log rotation precision

Logs are rotated and centered for maximal raw material usage and, thus, best economic yield for sawmills. Accuracy and precision of log rotation systems have not, however, kept pace with the development of modem cutting machines and production control systems. Average rotation errors up to, and more than, 20 degrees have been recorded. Our studies indicate that rotation errors can be reduced by improving the operation of rotation and centering mechanism. The log rotation is also influenced by a multitude of other factors, such as data transmission and conveyor system structure. The purpose of this study has been to investigate how well the optimized log rotation command, measured and analyzed by 3D-log scanners at the saw house log infeed, is materialized in the log rotation and positioning mechanism before the primary saw machine. The results show that there is much room for improvement, in both mechanics and data transmission systems in this most basic and important stage of cutting logs.