Correct grinding geometry with weaknesses in the drill orientation

However, a sticking point is the orientation of the drill, which decides on the grinding result (including clearance angle). The device is able to align the drill reproducible but:

The drills are not aimed directly at the cutting edge, but about 5 mm behind (in the direction of drill shank). Thus, both the twist angle and the design of the chip (and dirt) have influence on the direction.

It would make a difference if the drill from the Ausrichtstelle with 30 degrees to the top "weiterwendelt" or with 27 or 45 degrees. Depending on the angle of twist (5 mm behind the vagina despite the same clamping position) are the main cutting directly aligned quite different at the cutting edge. And this difference in orientation causes a distinctly different grinding results. There are also tolerances in the clamping length, which I could not avoid due to the somewhat elastic plastic parts.

Apparently, the device has been developed in USA and therefore potentially on the basis of standards that apply there for drills. In a rolled drill DIN and 30 degrees helix angle I get anyway by default no clearance angle ground. In some reviewers have stated and I agree as to. The 500 X allows fortunately the adjustment of the clearance angle on the drill orientation. So I got the drill eventually honed well.

With the described knowledge, you can see the correct setting at least visually check. On the end face of the chuck there is a mark which can be compared with the orientation of the main cutting edges. A once found optimal alignment can be made again and again - regardless of the angle of twist.

The acquisition has thus paid off. Precise Bohrerschleifvirrichtung is not to have by far for a prize of this magnitude.