Echo 71854 - Manual (Page 19)

PTO CHIPPERS 17
6.1 sHarPening cHiPPer blades
service & mainTenance
Warning
Before inspecting or servicing any part of the machine,
disengage PTO 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.
Section
Warning
The rotor assembly has a lock mechanism. When
working on the rotor assembly, use the lock mechanism
at all times. remove plastic bearing cover under the
chipper chute. There is a hole in the rotor jack shaft
and a matching hole in the bracket mounted to the ro-
tor bearing front side. install a punch through the rotor
shaft and bracket to lock the rotor in place.
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 two 3/8 inch retaining bolts holding access
cover to main frame assembly.
2. Tilt access cover over to expose rotor. rotate the ro-
tor so that the bolts holding a chipping blade are most
accessible.
3. remove the two hex nuts holding the blade itself.
repeat for all four blades. The four chipping blades
have two edges per blade and can be reversed one
time each before sharpening. if both sides have not
been used, remove and reverse the chipping blades.
reinstall chipping blades and proceed with chipping.
To grind the angled edge of the chipping blade to 45
degrees (see figure 6.1): 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 120 ft-lbs. close cover and replace bolts.
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 chip-
per.
• Small diameter branches do not self-feed.
• Chips discharge unevenly or have stringy tails–espe-
cially 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.
6.2 seTTing blade clearance
The four-edged chipping anvil located directly behind the
chipper chute should clear the chipping blade by 1/16
inch to 3/16 inch. The chipping anvil is adjustable and
reversible.
To adjust:
1. lift rotor access cover and expose rotor. loosen the
three 1/2 inch bolts that hold the chipper anvil to the
frame.
2. Measure the amount of clearance between chipping
blade and chipping anvil from inside of housing.
3. Adjust inward or outward to desired measurement.
4. Tighten bolts on chipping anvil to 75 ft. lbs. and resume
operation.
Figure 6.1, Sharpening the chipper blades
6