Warning, Warning 5.2 chipper blades – Echo 7812086 Owners Manual v.2 User Manual

Page 18

Bear Cat Owners Manual

SERVICE & MAINTENANCE

BEFORE INSPECTING OR SERVICING ANY PART OF THIS MACHINE, SHUT OFF POWER SOURCE, REMOVE KEY,

DISCONNECT THE BATTERY CABLES AND MAKE SURE ALL MOVING PARTS HAVE COME TO A COMPLETE STOP.

WARNING

5.2 CHIPPER BLADES

The chipper blades will eventually become dull, making chipping

difficult and adding extra strain on the machine. Poor chipping

performance is usually a result of dull chipping blades. It is

recommended that the blades be sharpened every 5 - 15 hours

or if your chipper’s performance has decreased. Check for the

following symptoms and sharpen the blades if needed.

Severe vibration when feeding material into the chipper.
Small diameter branches do not self-feed.
Chips being discharged are small, 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:

There are cracks, broken corners or nicks greater than 1/8"

(Figure 5.1).
The base of the cutting edge is worn or has been resharp-

ened so that the edge extends less than 1/16" above the

rotor chipping slot.

1.
2.
3.

5.2.1 REMOVING THE BLADES

Raise the rotor cover using the rotor cover jack (Section 4.4)

and secure with the lockup pin (Figure 4.2).
Rotate the disk until a chipper blade is accessible.
Secure the disk to prevent movement while removing the

chipping blades.
Remove the three 5/8" x 3" bolts and nuts holding the

chipper blade to the disk and remove the blade; repeat for

remaining blades.
Inspect blades to see if cracks or nicks are visible. If cracks

are present, replace the blades. If nicks can not be removed

by sharpening blade, replace the blade.

2.
3.

WARNING

Chipping blades are sharp! Use caution when working on

machine to avoid injury. Secure the chipping disk before

inspecting, removing or installing chipper blades.

Figure 5.1 - Causes for Replacement

1/8"

5.2.2 SHARPENING THE BLADES

Never sharpen or grind the mounting surfaces of the blades.

This will cause the edge to roll and the blade will be damaged,

resulting in poor chipping performance.
Regrind the angled edge of the chipping blades to 45 degrees

(Figure 5.2).
The blades can be ground on a bench grinder or by a pro-

fessional.
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.
Remove an equal amount off each blade to maintain rotor

balance.
Small imperfections such as nicks and burrs on the flat side

of the blade will not affect the chipping performance of the

machine.
For blades that have been repeatedly sharpened, ensure

that the sharpened surface extends past the chipping slot

opening. If it extends less than 1/16" above the opening,

the blades should be replaced.

5.2.3 INSTALLING THE BLADES

Secure the disk to prevent movement during installation.
Place a blade on the disk and attach with three 5/8" x 3"

bolts and nuts. Torque to 230 Ft-lbs. Repeat for remaining

blades.
Lower the rotor cover using the rotor cover jack (Section

4.4).
Secure the rotor cover to the chipper housing using two 1/2"

x 1-1/4" bolts, nuts and washers.

1.
2.

Figure 5.2 - Double Edged Blade

MOUNTING SURFACE
DO NOT GRIND

MOUNTING SURFACE

DO NOT GRIND

SHARPENED
SURFACE

45˚

.63