Page 103 - Demo

101GENERAL PURPOSE DRILLINGDR-TWISTThe DR line of holemaking tools is designed to provide an economical solution, suitable for all types of materials. These tools are designed primarily for semi-finishing operations and exhibit a high level of accuracy, even when subjected to interrupted cut machining conditions, or while drilling stacks or sloped surfaces. Furthermore, with the right edge geometry these tools can easily perform an angular penetration holemaking operation, drilling into the material and exiting with flat burr-free exit.These tools are known to be less susceptible to unstable machining conditions, making them ideal for unbalanced holemaking operations associated with vibration. An optional use of DR drills is for removing material from deep cavities %u2013 similar to the plunger%u2019s function. The material removal rate is lower than that of the plunger, but the tooling cost is also lower. In interrupted cutting, it is recommended to reduce the machining conditions by 50%.Attached is a sketch and the calculations required for the correct overlapping sidestep pattern which must be employed so the drill will function properly and fully cover the surface to be removed.P = %u221aZ2 %u2212 L2Z = 2R %u2212 XL = R %u2212 X/2ZXPX2LLRL