Echo 72928 Instruction v.3
6” Chippers CH6670H (76624), CH611DH
(76628), CH6993H (76635), 74624 & 74628:
Instructions
SUBJECT: CHIPPER BLADE
REPLACEMENT KIT
FITS MODELS: ALL 4.5", 6", 8" & 9"
CHIPPERS
WARNING
The chipping blades are sharp! Use care when working
on the machine to avoid injury.
WARNING
Before inspecting or servicing any part of this machine,
shut off power source, disconnect spark plug wire from
spark plug and make sure all moving parts have come
to a complete stop.
The Chipper Blade Kit contains new parts for replacing
worn or damaged blades for your chipper. Follow the steps
below to replace the chipping blades.
REPLACING THE CHIPPING BLADES
4.5” Chippers:
Remove the two 3/8" x 5-1/2" bolts securing the 1.
deector or discharge tube to the chipper housing and
loosen the 5/16" ange nuts on the weldment bolts.
Remove the two 3/8” retaining bolts holding the access 1.
cover to the main frame assembly.
Tilt the access cover over to allow access to the 2.
rotor.
Rotate the disk until a blade is accessible. 3.
Install a punch into the hole in the disk to hold the disk 4.
in place.
Remove the security lock nuts (on back side of chipper 5.
disk) and the at head screws holding the blades to the
disk. Remove old blades and install the replacement
blades with new hardware. Torque to 120 Ft-lbs.
To access the remaining blades, remove the punch, 6.
rotate the disk 90 degrees and reinstall the punch.
6", 8” and 9” Chippers CH6614 (71620),
CH6614H (72620), CH8540 (71854), CH9540H
(72854), 74824, CH911DH (72928), 72942,
CH500H (74500) CH800H (74800), 72884,
CH922DH (74950), CHF9540H (76854),
CH6670H (76824), CH8993H (76835):
Remove the two 3/8” retaining bolts holding the access 1.
cover to the main frame assembly. Tilt access cover
over to allow access to the rotor.
Rotate the rotor so that the bolts holding the chipping 2.
blade are accessible.
Install the disk lock by removing the plastic bearing 3.
cover beside the chipper chute.
Remove the deector.2.
Rotate the chipper disk until the hole on the chipper 3.
paddle is aligned with the hole on the chipper
housing.
Install a punch or screwdriver into the holes. One of 4.
the bolts from removing the chipper deector can also
be used to lock the disk.
Remove the security lock nuts (on back side of chipper 5.
disk) and the at head screws holding the blades to the
disk. Remove old blades and install the replacement
blades with new hardware. Torque to 120 Ft-lbs.
Replace the deector or discharge tube and resume 6.
chipping.
Chipper Blade Replacement Kit
Install a punch through the hole in the rotor shaft and 4.
the matching hole in the bracket mounted to the rotor
bearing front side to lock the rotor in place.
Remove the security lock nuts (on back side of chipper 5.
disk) and the at head screws holding the blades to the
disk. Note that the Orchard Chipper (CHF9540H) does
not have security lock nuts holding the blades.
Remove old blades and install the replacement blades 6.
with new hardware.
Torque to 25 Ft-lbs for Orchard Chippers (CHF9540H) 7.
and to 120 Ft-lbs for all other chippers.
Secure the access cover to the main frame and resume 8.
chipping.
PN 73579-00
Rev. 031308
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
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.
SHARPENING THE CHIPPING
BLADES
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.
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 permanent damage. Replace the blade if:
• There are cracks, broken corners or nicks greater than
1/8" (see below).
2. Regrind the angled edge of the chipping blades to 45
degrees. Make sure some type of xture 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 at 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.
• 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).
Double Edged Blade (PN 71122)
Double Edged Blade (PN 70739).
Chipper Blade Replacement Kit
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