Plain Milling Cutters (Helical Teeth)
of the work. Raise or lower the wheelhead a pre-
determined amount to give the correct clearance angle.
Follow the steps listed here to sharpen plain milling
To determine the amount to raise or lower the wheel-
cutters with helical teeth:
head, multiply the clearance angle (in degrees) by the
diameter of the wheel (inches) and then multiply this
1. Remove all accessory equipment from the
product by the constant 0.0087.
When you use a cup wheel, mount the tooth rest on
2. Clean the table and the bottoms of the
the wheelhead. Position the center of the cutter in the
same plane as the tooth rest. Then, raise or lower the
wheelhead the proper amount to give the desired
3. Mount the footstocks on the table. Allow just
clearance. To determine the amount to raise or lower the
enough space between them to accommodate the
wheelhead, multiply the clearance angle (in degrees) by
mandrel with a slight amount of tension on the
the diameter of the cutter (in inches) and then multiply
this product by the constant 0.0087.
Some tool and cutter grinders have a tilting wheel-
4. Swivel the wheelhead to 89°. (This allows the
head or a clearance setting device. Where you use a
end of the cutter to clear the opposite cutting face when
tilting wheelhead, simply tilt the wheelhead to the
you use a cup-type wheel.)
desired clearance angle. If you use a clearance setting
5. Mount the wheel and the wheel guard.
device, follow the steps listed here.
6. Use a dressing stick to thin the cutting face of
1. Clamp a dog to the mandrel on which the cutter
the wheel to not more than 1/8 inch. Use a diamond
truing device to true the wheel.
2. Insert the pin on the side of the dog into the hole
7. Use the centering gauge to bring the wheelhead
in the clearance setting plate that is mounted on the
axis into the same horizontal plane as the axis of the
3. Loosen the setscrew in the clearance setting
plate and rotate the cutter to the desired setting
8. Mount the cutter on a mandrel. (A knurled
(graduations found on the clearance setting plate).
sleeve on the end of the mandrel will help the mandrel
maintain an even, effective grip while you grind the
4. Tighten the setscrew.
5. Remove the dog.
9. Mount the mandrel between the footstock
When you grind the teeth of end mills, side milling
centers, preferably in a position so that the grinding
cutters, or stagger tooth cutters, use the graduated dials
wheel cuts onto the cutting edge of the teeth.
on the workhead to set the clearance angle.
10. Mount the plain tooth rest holder (with a
rounded tooth rest blade) on the wheelhead.
CUTTER SHARPENING SETUPS
11. Place the centering gauge on top of the
Tool and cutter grinders vary in design and in the
wheelhead and the tip of the gauge directly in front of
type of accessory equipment; however, most tool and
the cutting face of the wheel, and then adjust the tooth
cutter grinders operate in the same way. By using only
rest blade to gauge height. (This brings the blade into
the standard workhead, footstocks, and tooth rest blade
the same horizontal plane as the footstock centers.)
holders, you can sharpen practically any cutter. In fact,
you can sharpen most cutters by using essentially the
12. Traverse the saddle toward the wheelhead until
same method. Study the following sections, use a little
one tooth rests on the tooth rest blade; then lock the table
ingenuity and forethought, and you will be able to
sharpen any cutter that may be sent to your shop.
13. Let a cutter tooth rest on the tooth rest, and then
The following sections cover the sharpening of
lower the wheelhead until the desired clearance is
various types of cutters in various depths of detail. We
shown on the clearance setting plate. If you have no
have provided more detail in the explanation of how to
clearance setting device, calculate the distance to lower
sharpen a plain milling cutter with helical teeth because
the wheelhead using the method described earlier in this
this method is basically used to sharpen many other