Echo 72620 - Manual (Page 17)

6 INCH CHIPPER 13
SERVICE & MAINTENANCE
BEFORE INSPECTING OR SERVICING ANY PART OF THIS MACHINE, SHUT OFF POWER SOURCE,
ANd MAKe suRe All MoVINg PARts hAVe CoMe to A CoMPlete stoP.
Warning
5.2 chiPPer blade mainTenance
Warning
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 rotor bearing front side. Install a punch through
the rotor shaft and bracket to lock the rotor in place.
1. Remove the two retaining bolts holding access cover
to main frame assembly.
2. tilt access cover over to allow rotor access. Rotate
the rotor so that the bolts holding a chipping blade are
most accessible.
3. Remove the two 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.
Figure 5.1, Sharpening the chipper blades
45˚
SHARPENED
SURFACE
MOUNTING SURFACE
(DO NOT GRIND)
.38
SHARPENED
SURFACE
MOUNTING SURFACE
(DO NOT GRIND)
The chipper blades will eventually become dull, making
chipping difficult and adding extra strain on the machine.
checK The sharPness of The blades everY
5 - 15 hours of oPeraTion and sharPen as
needed.
Your blades need to be sharpened if:
•
Machine vibrates severely when material is fed 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:
•
there are cracks, broken corners or nicks greater than
1/8" (see below).
5.3 removing The blades
NICK GREATER
THAN 1/8”
CRACK
GREATER
THAN 1/8”
BROKEN
CORNER
• The base of the cutting edge is worn or has been re-
sharpened so that it no longer extends past the chipping
slot (see below).
NEW
BLADE
CHIPPER
DISC
CHIPPING
SLOT
CHIPPER
DISC
BLADE IS
TOO SHORT,
MUST BE
REPLACED
CHIPPING
SLOT
The blades can be ground on a bench grinder or by a
professional.
Never sharpen or grind the mounting surfaces of the 1.
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
2.
degrees (Figure 5.1). 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
3.
become overheated and change color. this will remove
the heat-treated properties.
use short grinding times and cool with water or some
4.
type of liquid coolant.
Remove an equal amount off each blade to maintain
5.
rotor balance.
Small imperfections such as nicks and burrs on
6.
the flat side of the blade will not affect the chipping
performance of the machine.
For blades that have been repeatedly sharpened,
7.
ensure that the sharpened surface extends past the
chipping slot opening. If it does not extend past the
opening, the blades should be replaced.
5.4 sharPening The blades