Instruction Manual
Section Five
slightly loosen the Hand-Nut on the BA940 toothrest that holds the toothrest
cross arm and blade rigid, and move the cross arm and blade slightly toward
the high tooth, reclamping the Hand-Nut. Grind the next two teeth and
check them again. When height is within tolerance, continue to sharpen the
primary relief on all teeth until they appear sharp.
E. Grind the secondary clearance, as explained in Chapter 3, but with the follow
ing modification. Since the stagger tooth cutter has differing axial rake angles
for each helix direction, it is necessary to grind one set of teeth completely,
then the other Select a tooth and mark its center with a pencil, using the
height gauge. Place the mark on the centerline level of the cutter. Rotate
the cutter above or below this mark for desired secondary clearance by wheel-
head movement, or move the toothrest by using a micrometer toothrest, its
blade positioned against the same tooth Swivel the table 2 to 6 degrees de
pending on the axial rake. The Wheelhead should be in horizontal position
(zero degree tilt)
F. If it is necessary to grind the side teeth ( to reduce cutter width, for example )
place the cutter on an adapting arbor and mount it in a universal workhead.
The set-up and procedure are similar to grinding the side teeth of a straight-
tooth milling cutter, or the face of a shell end mill (see pages 38 or 44). Refer
to Photo 29. Teeth are leveled with a gauge; then the workhead spindle is
locked. Mount the toothrest assembly on either the workhead or the table,
using the spring-loaded micrometer blade. Grind one set of teeth at one setting
'primary and secondary ); then reverse the cutter on the arbor and grind the
other set. By means of the swivel table, place about
½
degree back taper on
the primary clearance to create a larger cutter width at the periphery of cutter.
CHAPTER 7
Angular Cutters
I.
PREPARATION FOR SHARPENING THE PERIPHERY
(SEE PHOTO 30 AND 31)
PHOTO 30 PHOTO 31
A. The set-up for sharpening an arbor-mounted angular cutter is the same as that
for sharpening the periphery of a plain milling cutter, except that the table
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