Echo Bear Cat 70520 - Manual (Page 14)

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3.1 Removing Discharge Screen
1. Remove the discharge screen by removing the two
5/16 inch retaining bolts from the bottom of the
screen.
2. Pull the bottom of the screen outward. This will
cause the screen to rotate off the lip on top and fall.
3. To reinstall the discharge screen, place the top lip of
the screen into the slot under the top slope.
4. Rotate the screen so that the bolt holes align with
the holes in the chipper base and the plate butts
against the kicker bar.
5. Reinstall bolts and torque to proper specs.
3.2 Sharpening Chipper
Blades
The chipper blades will eventually become dull, making
chipping difficult. 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 discharge screen by removing the 5/16
inch retaining bolt and pulling the screen outward.
2. Romove the access cover on the chipper chute side
of the machine.
3. Rotate the rotor so that the bolts holding the chipper
blade are most accessable.
4. Remove the two hex head bolts holding the blade
itself. Repeat for all four blades.
Grind the angled edge of the chipping blade to 45
degrees (see figure 6): Grind the blades on a slow-speed
wet grinder if possible, or have them sharpened by a
professional. If you use a bench grinder, be careful when
grinding so that the blade material does not get too hot
and change color–this will remove the blade's special
Service and Maintenance
Before inspecting or servicing any part of the
machine, shut off the engine, 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.
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 20 ft. lbs.
NOTE: Never sharpen or grind on the back side of the
chipper blade. This will cause the edge to roll and the
chipping blade will be damaged, causing poor chipping and
feeding of material. Small imperfections, nicks, burrs, etc.
on the flat side of the blade will not affect performance of
the machine.
3.2.1 Chipping Blade Sharpening
Tips
Poor chipping performance is usually a result of dull
chipping blades. If your chipper's performance has
decreased, check for the following symptoms:
• Severe vibration when feeding material 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:
• The blade is cracked (especially around the bolt
holes) or the edges are too deeply chipped to be
ground smooth.
• The base of the cutting edge is worn or has been
re-sharpened so that it is too close to the rotor
chipping slot.
45 0
6
S E C T I O N 3