Instruction Manual
Section Five
and is not intended to compete with production spiral grinders that grind
by template or sine bar camming methods.
PHOTO 69 PHOTO 70
(a) Mount the universal workhead to the left side of the grinder as
shown in Photo 69. To facilitate toothrest placement, it may be
helpful to off-set toward the machine front the workhead base from
the table center. Mount the cutter shank or arbor in the workhead.
(b) Mount a straight wheel about 5 or 6 inches in diameter, such as the
K. O. Lee PV5FH60 or PV7GM46. Mount a wheel guard. Since
the back side of each tooth forms an angle with the tooth face, it
will be necessary to dress the periphery of the wheel relative to its
side at this angle. This angle is a straight line always at an angle
relative to the mill axis which is moved along the length of the flute
describing a helical plane which is the tooth back. Sight along the
mill's axis from the right side of the table in order to determine the
approximate angle. The wheel periphery should be wide enough to
cover the tooth back. Use the diamond dresser to create the angle
on the wheel periphery. Use the abrasive wheel dresser or other
means to dress a small radius on the wheel edge at its largest diam
eter side. The radius size is not important as it will break down in
the f l u t i n g process, but it must assist in recreating the original
gullet, radius, and rake on the tooth face. It is the curved periphery
of the wheel edge that generates the radius and curved rake of the
cutting face.
(c) Place the straight wheel at an angle relative to the cutter axis which
will be slightly greater than the actual cutter helix. Some experi
mentation is necessary to place the wheel side, corner radius, and
peripheral angle so that it will correspond to the tooth face, gullet
radius, and preceeding tooth back. Once the alignment of the wheel
to the cutter has been made, do not move the machine Crossfeed.
(d) Since rapid lowering of the Wheelhead will take place during the
grinding, it is necessary to set the fixed toothrest on the front saddle
surface rather than on the Wheelhead. A special t-slot block (SUCH
AS THE B670T SHOWN IN THE PHOTO) or other adapting plate
which can hold the base of the universal toothrest is needed. Adjust
the crossarm so that the fixed blade of the small micrometer rest is
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