Echo 71825 - Manual (Page 12)

10
Service and Maintenance
Sharpening Chipper
Blades
See Figure 7
WARNING: Before inspecting or servicing any part of the machine, shut off
the power source, disconnect the spark plug wire from the spark plug, and
make sure all moving parts have come to a complete stop. The chipping
blades are sharp! Use care when working on machine to avoid injury.
WARNING: The rotor assembly has a lock mechanism. When working on
the rotor assembly, use the lock mechanism at all times. Remove plastic
bearing cover under chipper chute. There is a hole in the rotor jack shaft
and a matching hole in the bracket mounted to the rotor bearing front side.
Install a punch through the rotor shaft and bracket to lock the rotor in
place.
Check the engine oil, and change the oil and filter as recommended in the
manual. Service and replace the air cleaner as recommended.
The chipper blades dull, making chipping difficult. The chipper blades are two
edged. When the first edge dulls, flip the blade to use the sharp second edge.
After both edges are dull, sharpen the chipper blades. It is recommended that
the chipper blades are sharpened every 5-15 hours of chipper operation. To
remove the chipping blades for sharpening:
1. Remove the two 3/8 inch retaining bolts holding the access cover to main
frame assembly.
2. Tilt access cover over to allow rotor access. Rotate the rotor so that the
bolts holding a chipping blade are most accessible.
3. Remove the two hex head bolts holding the blade itself. Repeat for all four
blades. The four chipping blades have two edges per blade and can be
reversed one time each before sharpening. Reinstall chipping blades and
proceed with chipping.
To grind the angled edge of the chipping blade to 45 degrees (see figure 6):
Grind the blades on a bench grinder or have them sharpened by a professional.
Be careful when grinding so that the blade material does not get too hot and
change color–this will remove the blade's special heat treated properties. Use
short grinding times and cool with water. Try to remove an equal amount off
each blade to maintain balance. Replace the chipping blades and tighten bolts
to 75 ft. lbs.
0.38
45 ⋅⋅⋅⋅⋅
Sharpening
Edges
t
s
t t
Figure 6
Figure 7