Echo 73710S - Manual (Page 9)

6
Sharpening Cutting Teeth
The carbide cutting teeth should stay sharp for two
to four hours of normal operation. It is possible to
manufacture harder cutting teeth, but these are more
likely to shatter or chip. A person familiar with
sharpening carbide should use the following
instructions to sharpen the cutting teeth after every
two to four hours of operating time.
Instructions for Sharpening Cutting Teeth
(See figures 5a - 5d, pg. 9.) The cutting teeth will
last longer if you maintain the original contour of the
tip as closely as possible during grinding. Duplicate
all clearance and relief angles. Be sure to leave
adequate steel to support the carbide.
Dry grinding is suggested when sharpening to
reduce the chance of cracking from insufficient
coolants. Dry grinding also allows better visibility and
longer wheel life because you will have better control
of your grinding action.
Move cutting teeth constantly when in contact with
the grinding wheel surface to reduce heat
concentration which may damage the teeth. This
method will reduce uneven wheel wear.
Use a silicon carbide grinding wheel for the carbide
portions of the teeth. You can grind the steel portions
of the teeth with a carbide wheel, but the wheel will last
longer if you use an aluminum oxide wheel for the steel
portions.
The following wheels are recommended:
• Silicon carbide 60 grit for carbide.
• Aluminum oxide 24 grit for steel.
Caution: Always use a guard over the grinding
wheel.
Never place the cutting teeth in water immediately
after grinding; this may crack the carbide tip. Although
carbide is many times harder than steel, it does not
have the same thermal characteristics.
Sharpening Cutter Teeth
Sharpening Cutter Teeth