Echo 72928 Instruction v.3 - Manual (Page 2)

Chipper Blade Replacement Kit
SHARPENING THE CHIPPING
BLADES
Chipper blades consist of two edges. When the first edge
dulls, inspect the blade to ensure the second edge is in
good condition. if so, flip the blade and tighten to the
proper torque to use the second sharp edge. after both
edges are dull, sharpen the chipper blades.
Double Edged Blade (PN 71122)
Double Edged Blade (PN 70739).
The chipper blades will eventually become dull, making
chipping difficult and adding extra strain on the machine.
CHECk THE SHARPNESS OF THE BLADES EvERy
5 - 15 HOURS OF OPERATION AND SHARPEN AS
NEEDED.
Your blades need to be sharpened if:
•
machine vibrates severely when material is fed into the
chipper.
• small diameter branches do not self-feed.
• Chips discharge unevenly or have stringy tails,
especially when chipping green branches.
Before you sharpen the chipping blades, check for perma-
nent damage. Replace the blade if:
•
There are cracks, broken corners or nicks greater than
1/8" (see below).
• The base of the cutting edge is worn or has been re-
sharpened so that it no longer extends past the chipping
slot (see below).
The blades can be ground on a bench grinder or by a
professional.
1. never sharpen or grind the mounting surfaces of the
blades. This will cause the edge to roll and the blade will
be damaged, resulting in poor chipping performance.
2. Regrind the angled edge of the chipping blades to 45
degrees. Make sure some type of fixture is used to
correctly hold the blade at the proper angle.
3. Be careful when grinding so that the blade does not
become overheated and change color. This will remove
the heat-treated properties.
4. Use short grinding times and cool with water or some
type of liquid coolant.
5. Remove an equal amount off each blade to maintain
rotor balance.
6. small imperfections such as nicks and burrs on
the flat side of the blade will not affect the chipping
performance of the machine.
7. For blades that have been repeatedly sharpened,
ensure that the sharpened surface extends past the
chipping slot opening. if it does not extend past the
opening, the blades should be replaced.
NICK GREATER
THAN 1/8”
CRACK
GREATER
THAN 1/8”
BROKEN
CORNER
NEW
BLADE
CHIPPER
DISC
CHIPPING
SLOT
CHIPPER
DISC
BLADE IS
TOO SHORT,
MUST BE
REPLACED
CHIPPING
SLOT
45˚
SHARPENED
SURFACE
MOUNTING SURFACE
(DO NOT GRIND)
.38
SHARPENED
SURFACE
MOUNTING SURFACE
(DO NOT GRIND)
45°
.25
MOUNTING SURFACE
(DO NOT GRIND)
MOUNTING SURFACE
(DO NOT GRIND)
SHARPENED
SURFACE
SHARPENED
SURFACE
IMPORTANT