The third influence of the tool diameter ratio D1 /d is illustrated
in Fig. 10. Due to the low rolling angle (Fig. 11) the damage is also lower and, therefore, the ball spinning performance is increased by using a big ball diameter with a high feed rate.
The simulations show, that the highest Ayada damage accrues
below the surface (Figs. 11 and 12). That is the reason why the
surface of the experiment scales when the damage is too high. The
experiments fit the results of the statistical design of simulations