Echo Bear Cat 75111 - Manual (Page 22)

Page 16 Bear Vac Pro Operator’s Manual
CHIPPER BLADE
5/16" FLAT
WASHER
5/16" X 3/4"
BOLT
ACCESS COVER
5/16" FLAT
WASHER
5/16" NYLOCK
NUT
REMOVING THE CHIPPER BLADES
Service & Maintenance
Chipper blades must always be kept sharp! It is
recommended they are sharpened approximately every 8
hours of chipping operation, or when branches no longer
self feed. If the blades aren’t sharp severe vibration and
difficulty in chipping will develop.
To remove the chipper blades:
1. Start by removing the chipper blade access cover by re-
moving the 5/16” bolt and washer.
2. Using a block of wood, or a screwdriver, secure the rotor
so it is not able to spin.
3. From the bottom, remove the 5/16” bolts holding the chip-
per blades onto the rotor.
4. Replace, reverse, or sharpen the blades.
5. Reinstall the 5/16” bolts and tighten to 20 ft/lbs of torque.
Flip the blade or regrind the angled edge of the chipping
blades to 45 degrees. (refer to figure below) The blades can
be ground on a bench grinder or by a professional. Make
sure some type of fixture is used to correctly hold the blade
at the proper angle. Be careful when grinding so that the
blade does not become overheated and change color. (This
will remove the heat-treated properties) Use short grinding
times and cool with water or some type of liquid coolant.
Try to remove an equal amount off of each blade to maintain
rotor balance.
Never sharpen or back grind the flat side of the chipping
blade. This will cause the edge to roll and the chipper blade
will be damaged, resulting in poor chipping performance.
Small imperfections such as nicks, burrs, etc. on the flat
side of the blade will not affect the chipping performance of
the machine.
SHARPENING THE CHIPPER BLADES
Fig. #19, Access panel removal
Fig. #20, Chipper blade sharpening
45°
SHARPEN TO A 45° ANGLE.
FLAT SIDE
NEVER SHARPEN OR BACK GRIND THIS SIDE -
POOR FEEDING AND CHIPPING WILL RESULT.