Grinding Steps Of Twist Drill Bits On APE40

APE40 is a kind of drill grinding machine with full functions, and it is very easy to operate. Furthermore, it is mainly used to grind step drills, tap and other various commonly used drills.

Grinding twist drill bits(point angle 90°-140°）

1. Position the tool holder head setting the required grinding angle on the external graduated scale 10 and lock it in position using lever33. 2. Enable oscillation of the head, so that pin 7 is in position B and tighten the lever locking screw 8. To achieve good grinding results it is essential that the screw is tightened. 3. Place green cam No.2 into the 1:2 ratio cam holder for right-hand bits and red cam No.1 for left-hand bits. 4. Prevent the chuck from rotating by inserting the positioning key 19 into the green phasing notch for right-hand bits indicated by D and R, or into the red phasing notch for left-hand bits indicated by S and L. These notches are the starting point for correctly phasing the tool with respect to the cam. 5. Put the Morse Cone onto the shake of the bit and then insert it from the rear of the chuck. 6. Clamp the bit in the self-centering chuck and then loosen it slightly so that the bit can rotate for correct positioning. (NOTE: Cylindrical shaft bits are held directly by the 6 jaws self-centering chuck that guarantees a concentric grip directly on the shank.) 7. Turn the bit so that the cutting edge rests on the step of the template 17 in correspondence to the value of the diameter of the bit to the ground. Bits with a diameter greater than 16 are always positioned on 16. Right-hand bits: Template step facing upwards, green, letters D and R. Left-hand bits: Template step facing downwards, red, letters S and L. 8. Clamp the bit. 9. Move the positioning template away and disengage the positioning key 19 tightening the knob 41 to allow the chuck to rotate. 10. In order to obtain a normal rake angle adjust the lever 4 until a value approximately equal to the diameter of the bit to the ground is shown on the index 8. To obtain a greater rake angle, position the index on a higher value. In order to obtain a lower rake angle, position the index on a lower value. 11. Using handwheels 11 and 13 bring the grinding wheel into the operating position and start the motor by pressing the start button 35.