As shown in Table 2, the relationship of the drill point angles of the twist drill and drilling forces is very irregular and complex to make the analytical model; it is needed to use the powerful predicting methods for empirical modeling.
In order to make the model of drill point angles for minimizing drilling forces, in this paper, MGGP method is adopted using the measurement data of Table 1 as training data.
The grinding tests were conducted using Biglide parallel machine and the drill point angles were measured to prepare the input values.
TABLE 4: PAIRED SAMPLES CORRELATIONS MESIO-DISTAL WIDTH OF SIX ANTERIOR TEETH AT MESIO-LABIO-INCISAL POINT ANGLE TO DISTO-LABIO-INCISAL POINT ANGLE
More over statistically significant correlation ex-isted for each pair between right side anterior maxil-lary teeth and left side anterior maxillary teeth as measured from contact point to contact point and measured from mesio-labio-incisal point angle to disto-labio-incisal angle as shown in Table 3 & 4.
Mesio-distal widths of each of the six anterior teeth was measured from contact point to contact point and from mesio-labio-incisal point angle to disto-labio-incisal point angle in this study which is its uniqueness as no other study of this kind is seen in literature.
Figures 22, 23 and 24 show the radial distance (r), the observation point angle ([phi]) and the channel angle ([theta]) effects on the peak of electromagnetic field components generated by inclined lightning channel, respectively while the basic current assumptions are obtained from Table 1.
Whilst Figure 23 shows that by increasing the observation point angle ([phi]) to 90 degrees, the peaks of electromagnetic fields have a downward trend until about 90 degrees when they are increased almost symmetrically with the first half.
Due to inclined lightning channel, the observation point angle ([phi]) is an effective factor for the evaluation of electromagnetic fields.
For example, the M 5 drill sharpener grinds point angles
from 90 deg to 190 deg, with clearance angles ranging from 0 deg to 30 deg.