Clearance angle
to max minus
Prism rest to
Pos.
A1
1 7
1 5.2
WEB THINNING OF DRILLS
Lock points
A:
Lock point for cutter, carbide drill.
crossfacet shape, four surface shape
B:
Lock point for back or free
sharpening
C:
Lock point for web thinning
Keep the prism support, as described before. Turn the clearance angle adjustment to 1
(see picture below). Fix the turning mechanism in hole
C
of the fixation plate (see picture
below). Shift the complete prism tretle to the left stop, adjust on mark
A1
.
By using the motor- and prism feed, grind inside the drill behind the drill cutting edge.
Note the graduation No. on the prism feed scale and go back for
3 complete
turns. Do
not chance the position of the motor feed. Open the clamping lever, reverse the prism, fix
again and thin the web of the other side.
A
B
C