Echo SG340 Owners Manual v.4 - Manual (Page 13)

STUMP GRINDER 9
ENGLISH
SERVICE & MAINTENANCE
Before inspecting or servicing any part of this machine, shut off power source,
and make sure all moving parts have come to a complete stop.
WARNING
5.3 sHarPen CuTTInG TeeTH
The carbide cutting teeth stay sharp for approximately
two to eight hours of operation. a person familiar with
sharpening carbide should use the following instructions
to sharpen the cutting teeth when they become dull.
To ShaRPEN ThE CaRBIdE TEETh:
1. Remove cutting teeth from cutter assembly by
removing the 1/2" bolt and washer from the spindle on
bottom disk and the twelve (12) 3/8" x 3/4" carriage
bolts and nylock nuts. See diagram below.
5.4 sHarPenInG GuIDe
• 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 due to better grinding action control.
• use a silicon carbide grinding wheel for the carbide
portions of the teeth. grinding the steel portions of the
teeth with a carbide wheel is possible, but the wheel
lasts longer if an aluminum oxide wheel is used for
the steel portions. The following wheels are recom-
mended:
• Silicon carbide 60 grit for carbide.
• aluminum oxide 24 grit for steel.
• 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. Refer to diagram below.
• Never place the cutting teeth in water immediately
after grinding; the carbide tip may crack. Carbide is
many times harder than steel, but does not have the
same thermal characteristics.
Position tip as shown here to sharpen. Use a side-to-side
motion while grinding to keep original radius. 15°
11°
Sharpen
this surface
2. grind teeth to sharpen, maintaining original angles.
duplicate all clearance and relief angles. The cutting
teeth last longer if the original contour of the tip is
maintained as closely as possible during grinding. Be
sure to leave adequate steel to support the carbide
(see below).
3. Replace sharpened cutting teeth on spindle.