Echo Bear Cat 70580S - Manual (Page 12)

9
Check the engine oil, and change the oil and filter as
recommended in the manual. Service and replace the air
cleaner as recommended.
3.1 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. Rotate the rotor so that the bolts holding the chipper
blade are most accessable.
3. Remove the two hex head bolts holding the blade
itself. Repeat for the second blade.
Grind the angled edge of the chipping blade to 45
degrees (see figure 7): 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 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.
3.1.1 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.
3.1.2 Setting Chipping Blade
Clearance
The chipping blades should clear the chipper block
located directly under the chipper chute by 1/16
inch to 1/8 inch. To adjust the blade clearance,
proceede as follows:
1. Remove the lower belt guard and the discharge
screen. Remove plastic cover from the rear rotor
bearing.
2. Loosen the set screws holding the lock collar on the
front and rear bearings.
3. Use a punch and hammer to to tap the lock collars
in a direction opposite of normal rotation so that
they rotate and can be removed.
4. Using a rubber mallet tap the end of the rotor shaft
to obtain 1/16 to 1/8 of an inch clearance (See
figure 8). The blade clearance can be viewed
through the discharge opening. Rotate the rotor and
check the cleanance on both chipping blades.
Service and Maintenance
S
E C T I O N
3
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.