​Drills

- Jan 30, 2018-

           Drills are tools used to drill through-holes or blind holes in solid material and re-hole existing holes. Drill commonly used mainly twist drill, flat drill, center drill, deep hole drill and set of drill. Reamers and countersinks, although they can not be drilled in solid materials, are customarily classified as drill bits.

Instructions 1, the drill should be installed in a special package, to avoid vibration collide with each other. 2, when used, remove the drill bit from the box should be installed into the spindle collet chuck or automatically replace the drill bit magazine. Use it back into the box. 3, measuring the diameter of the drill to use a tool microscope and other non-contact measuring instruments to avoid contact with the cutting edge and mechanical measuring instrument was bruised.

4, some CNC drilling machine using the positioning ring Some CNC drilling machine does not use the positioning ring, such as the use of fixed ring installation of the depth positioning must be accurate, such as the use of the positioning ring drill bit installed on the spindle elongation to be adjusted Consistent, multi-spindle drilling more should pay attention to this point, to make each spindle drilling depth to be consistent. If inconsistent it is possible to drill bit to the table or can not drill through the circuit board scrapped. 

5, usually 40 times stereo microscope can be used to check the drill cutting edge wear. 

6, should always check the concentricity of the spindle and the collet chuck and collet chuck clamping force, poor concentricity will cause a small diameter drill broken drill and large aperture and so on, the clamping force is not good will cause the actual speed and Set the speed does not meet, between the chuck and the drill slip. 

7, the fixed handle bit chuck on the spring chuck length of 4 to 5 times the diameter of the drill handle to clamp. 

8, should always check the spindle presser foot. The presser foot contact surface should be horizontal and vertical to the spindle can not be shaken, to prevent the drill cut and cut holes.

9, Drilling machine's vacuuming effect is better, vacuuming wind can reduce the bit temperature, while taking away the dust to reduce friction to produce high temperature. 10, the substrate stack including the upper and lower backing plate to drill in the workbench in a hole positioning system of a slot positioning jail, flat. The use of adhesive tape to prevent the drill bit drilling tape stuck to the drill bit chip, resulting in chip removal difficulties and broken drill. 11, order the manufacturer's drill, factory inspection to sampling 4% of its compliance with the provisions. And 100% with 10 to 15 times the microscope to check its nicks, abrasions and cracks. 12, timely grinding drill bit, bit can increase the use and re-wear the number of drill bit to extend the life and reduce production costs and costs. Usually measured by a tool microscope, the depth of wear should be less than 0.2 mm over the full length of the two main cutting edges. When grinding to wear to 0.25mm. Ordinary shank drill bits can be resized three times and undercut bits can be resharpened two times. Turning over the hole quality and precision of its drilling will decline, will result in scrapped PCB products. Overturn effect is counterproductive.

13, when due to wear and its wear diameter decreased by 2% compared with the original, the drill scrapped. 14, the drill bit parameter settings Under normal circumstances, manufacturers have provided a factory production drill bit drilling speed and speed parameters table, the parameter is only a reference, the actual process but also through the actual use of workers come to a meet The actual situation of the bit speed and speed parameters, usually the actual parameters and reference parameters are different but not much difference. 15, bit sharpening, should try to twist the two major cutting edge grinding symmetry, so that the two main cutting edge of the radial force offset each other to prevent bit deflection and aperture expansion.