6.
Set stop finger so that it will pick up the cutter
before the cutter engages the grinding wheel. See
Always adjust the centers so that the cutter can
rotate freely and yet not have any play or looseness. If the
cutter fits loosely on the centers it will be impossible to get
an accurate grinding job.
GRINDING SPUR BITS
1.
Set up grinder with work-head.
2.
Swing work-head to the right.
3.
Swing work-head up to a vertical position. See
illustration No. 25.
4.
Next select the collet necessary to mount spur bit
into collet head.
5.
Select a straight grinding wheel of the proper
thickness and dress the corners so that the
grinding wheel matches the end of the spur bit.
See drawing illustration No. 24.
6.
Re-adjust work-head as needed to permit grinding
ILLUSTRATION NO. 23
wheel to clear through end of spur bit and give
GRINDING A SPIRAL PLANER CUTTER
proper clearance.
7.
Make sure that the point of contact between stop
7.
Turn on grinder motor and grind one half of the
finger and cutter as well as between cutter and
end of spur bit by feeding grinding wheel down
grinding wheel are very close together. Caution it
onto the snug bit. See illustration No. 25. Be sure
is very important to get stop finger to contact the
to back up on feed handle to take slack out of feed
work piece as near to the same point that the
screw.
grinding wheel contacts the work. That is, if the
stop finger is too far ahead of the grinding wheel,
the cutter will drop off of the stop finger too soon
at the end of the grinding stroke. This will cause a
bell shape to be ground on the end of the spiral If
the stop finger is placed too far behind the
grinding wheel, the cutter will engage the grinding
wheel before the stop finger can pick it up.
8.
Turn on grinder motor and take a very light pass
on the cutter. Check the contact between grinding
wheel and cutter.
GENERAL NOTES ON GRINDING STRAIGHT AND
SPIRAL CUTTERS
In some cases, after grinding the cutter, the stop finger is
adjusted down a small amount and the cutter is re-ground.
This procedure will leave a narrow land on the cutter. The
land should be from 1/32 to 1/16 wide, see Illustration No.
18. This grinding procedure will produce a primary and
secondary clearance angle.
ILLUSTRATION NO. 24
DRESSING GRINDING WHEEL TO MATCH SPUR BIT
When grinding spiral or straight planer knives
always keep a light pressure on the cutter with your hand
so that the cutter will track on the stop finger. That is,
rotate the cutter against the stop finger and keep a light
pressure on the cutter as it travels along the stop finger.
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