Less grinding, first of all, "do not rub", get the drill, that is, grinding, certainly blind grinding. This is a very important step to lay a solid foundation for grinding the next step only when you put a good position before sharpening. The teacher in the demonstration process, according to the methods and skills of practice summed up in simple formulas form explanation and demonstration, students often listen to understand, to do the normal operation demonstration, step by step action demonstration, slow motion model, so that the students easy to accept. Here the use of four formulas to guide the grinding process. Better effect.
A bit, including a cutter rod, a cutter rod tip, tip two is located in a main plane (C - C) on the cutting insert (5, 5 '), the cutting blades (5, 5') have in common second planes (E - E). The orientation of the short cutting edge center. The blade forms a point like center, the cutting edge is used to enter the workpiece, and thereby the bit is aligned. Two chip grooves (6, 6 ') are arranged on the cutter bar, and the chip removing slots (6, 6') extend from the tip to the end. In any section along the bar, the flutes are located are diametrically opposed to each other's position in the flat tube, flat tube and two common edge edge in the pipe on both sides of the belt plane (F F) 90 degrees extension, wherein the knife rod has a maximum in the rigid plane. The orientation of the second plane (E E) of the center cutting edge is approximately 90 degrees with respect to the main rigid direction (F F) of the blade plane or the bottom of the cutter bar.
According to the different workpiece, the grinding method is different, the same material of different thickness, grinding method is also different. Refer to the formula: edge wheel surface on the drill shaft straight, oblique angle by the back edge out front, grinding back, up and down swing tail don't tilt.