Beside the twist drill, the effects of various drill geometries were rarely discussed in analytical fashion. This study presents a comprehensive analysis of delamination in use of various drill types, such as saw drill, candle stick drill, core drill and step drill. In this analysis, the critical thrust force at the onset of delamination is predicted and compared with the twist drill. © 2003 El...

To overcome strong drilling force and over high temperature during orthopedic surgery, the four medical drills with different geometrical shapes by using superhard materials were designed. The bone drilling temperature field of superhard drill was theoretical analyzed. Results showed that brazed step drill has the most ideal drilling temperature. It controls the maximum bone temperature below 4...

The conservation technologies and traditional techniques were evaluated at Adaptive Research Farm Gujranwala Pakistan during Rabi 2007-2008 and 2008-2009. The sowing techniques evaluated were broadcasting (T-1), Rotary Tillage Drill (T-2), Zero Tillage Drill (T-3) and Rabi Drill (T-4). Rotary Tillage Drill showed significantly high germination count (220.50 m -2 ) followed by Rabi Drill (211.50...

The dynamic model of a drill in drilling process was proposed and investigated in this study. To assure a good drilling quality, the vibration variation on the drill tips during high speed drilling is needed to be investigated. A pre-twisted beam is used to simulate the drill. The moving Winkler-Type elastic foundation is used to characterize the tip boundary variation in drilling. Due to the v...

The present work deals with developing a fuzzy back propagation neural network scheme for prediction of drill wear. Drill wear is an important issue in the manufacturing industries, which not only affects the surface roughness of the hole but also influences the drill life. Therefore, replacement of drill at an appropriate time is of significant importance. Flank wear in a drill which depends u...

This paper presents a new thermal model for bone drilling with applications to orthopaedic surgery. The new model combines a unique heat-balance equation for the system of the drill bit and the chip stream, an ordinary heat diffusion equation for the bone, and heat generation at the drill tip, arising from the cutting process and friction. Modeling of the drill bit-chip stream system assumes an...

The analysis of drill cutting angles is important for the design of high-performance drill geometry. The cutting angles along the cutting edge of a drill are determined by the combination of its flute and flank surfaces. This paper examines the analysis of both flute and flank surface models and the evaluation of drill cutting angles. A new mathematical model for an arbitrary drill flute face i...

Drilling is the most frequently employed operation of secondary machining for fiber-reinforced materials owing to the need for structure joining. Delamination is one of the serious concerns during drilling. Practical experience shows that an eccentric twist drill or an eccentric candle stick drill can degrade the quality of the fiber reinforced material. Comprehensive delamination models for th...