Drill point geometry

The drill point geometry is important in terms of making a damage-free hole in PMCs. The optimisation of drill... 

The trepanning tool reduces the thrust force and torque during drilling of GFRP composites as compared with the twist drill. The torque behaviour was similarly influenced by the drill point geometries and the feed rate. A decrease in the feed rate reduces the thrust force, which can reduce the... 

Thrust force for different drill point geometries... 

The ANN topology was adopted as a predictive tool. The cutting speed, feed rate, drill diameter and drill point geometry were nsed as the input parameters. The drilling-induced damage was the output. The maximum absolute error for training patterns was found to be 12.7 per cent and the minimum was 0.1 per cent, and for most cases the error was less than 5 per cent. The maximum absolute error for testing patterns was found to be 13.19 per cent and the minimum was 0.35 per cent (Mishra et al., 2010). 

An ANN predictive approach was developed with inputs as the drill point geometry, the feed rate and the cutting speed with residual tensile strength of composite with drilled holes as the output. The maximum absolute error for testing... 

Variations on conventional drill point geometry are aimed at reducing cutting forces and selfcentering capability and include four facet, helical, Racon, Bickford and split point. 

Center drilling usually required before drilling unless special drill point geometry used. 

Table 2 Common point geometries of twist drills (Konig and Klocke 1999 Heinemann 2004)...

To enable grid test points to be translated to exactly the correct target location on the product, it is important that each translator pin fall into the correct sequence of holes while the fixture is being assembled. If sufficient intermediate guide plates are employed, then the geometry of drilled holes can be so arranged that a virtual tunnel is created for each... 

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