Whilst the increasing size of AG, SAG and ball mill presents certain design issues common to all these ball mill types, certain issues are more relevant to the design of ball mill since: Ball mill are generally smaller in diameter relative to their lengths when compared with AG and SAG units; Ball mill has comparatively high charge densities when compared to AG and SAG ball mill; and Ball mill are rubber lined more often than AG and SAG ball mill .The progressive increase in the size of ball mill has led to an ongoing requirement for more accurate and reliable analysis of ball mill structures for a number of reasons :Those very large ball mill with geared drives typically use large outstand gears, The ball mill can have a significant effect on the stresses in the main ball mill structure. Consequently, these gears need to be modelled as part of the main ball mill analysis, in sufficient detail to establish the effect of the gear and gear loading on the ball mill structure. Separate nalysis of the gear structure is usually carried out.