Sharpening drill main master a few tips

1, the edge of the grinding wheel surface to settle .
Grinding bit before the first bit of the main cutting edge of the grinding wheel surface placed on a level surface , that Plate Compactor  is, to ensure the contact edge grinding surface, the blade to be ground . This is the bit position of the first step and the wheel relative to the position and then slowly to gracefully by grinding the surface .
2, the bit axis oblique to the surface with the wheel angle of 60 ° .
This angle is the angle of the drill front , then the angle is wrong, will directly affect the size and angle drill main cutting edge shape and chisel edge angle . This is the bit line and the wheel axis of the positional relationship between the surface , taking the line 60 ° , this angle is generally more accurate to see . Here we note that the relative levels before the drill grinding and angular positions , both overall plans , do not neglect to settle edge gracefully degree angle , or the angle to gracefully while ignoring settle edge .
3 , followed by the grinding edge back .
After contacting wheel edge , from the cutting edge to the back of the main mill , that is from the drill edge first came into contact with wheels, then slowly down along the entire flank wear . Drill cut can gently touch wheel , the first for a smaller amount of sharpening , and observe the spark uniformity, timely adjustment of hand size of the pressure , but also pay attention to the drill bit cool , not be allowed to wear too much, causing discoloration edge , and to the edge annealing . Discovery edge temperature is high, the drill should be promptly cooled .
4 blade to swing up and down the drill , drill the tail can not be warped .
This is a standard drill grinding operation , the main cutting edge to swing up and down on the wheel , that is, the front of the hand grip drill evenly to the surface of the wheel of the drill bit up and masonry drill bits  down. The hand grip part can not swing , but also to prevent the rear handle to the upturned , that can not drill the tail above the horizontal centerline Gao Qiao Yu wheel , otherwise it would blunt edge , not cutting . This is the most critical step drill bit worn good or bad, and this has a great relationship . In almost worn when started from the edge , back angle and then gently rub a bit so that the back is more smooth some of the edges .
5, to ensure cutting edge right axis symmetrical on both sides slowly repair .
After grinding the side edge , and then grind the other side of the blade , blade must ensure that the axis of the drill in the middle of both sides of the blade to be symmetrical . Experienced master will look toward the light drill tip symmetry , proceed slowly grinding . After the drill cutting edge angle is generally 10 ° -14 °, posterior horn of the big, the cutting edge is too thin , powerful vibration when drilling , triangular or pentagonal orifice was the chip acicular ; posterior horn of the small, axial force when drilling large, easy to cut , cutting force increases, the temperature rise hole saw blades  big , drill severe fever , not even drilling . Angle after angle grinding suitable Feng-Jian pairs, two-edged symmetrical , drilling , drill chip light, no vibration, aperture is not expanded.
6 , two after a good grinding of larger diameter drill bit drill grinding also pay attention to Feng-Jian .