Echo Bear Cat 70554S - Manual (Page 14)

11
Service and
Maintenance
Caution: 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.
Engine Models: 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.
3.1.1 Removing the Chipping Blades
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 accessible.
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 4-7, pg. 18): 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. After sharpening, 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 the performance of the machine.
3.1.2 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.
3.1.3 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, proceed 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 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 4-8, pg. 19). The blade clearance can be
viewed through the discharge opening. Rotate
the rotor and check the clearance on both chip-
ping blades.
S E C T I O N 3