Maintenance; Sharpening The Saw Chain - Makita UC3050A Bedienungsanleitung

MAINTENANCE

CAUTION:
Always be sure that the tool is switched off and
•
unplugged before attempting to perform inspection
or maintenance.
Always wear gloves
•
inspection or maintenance.
Never use gasoline, benzine, thinner, alcohol or
•
the like. Discoloration, deformation or cracks may
result.
Carry out the maintenance work described below at
regular intervals. Warranty claims will be accepted only
if these operations have been performed regularly and
properly.
Only maintenance work described in this instruction
manual may be performed by the user. Any other work
must be carried out by MAKITA authorized service
centers.
Cleaning the chain saw
Clean the saw regularly with a clean rag. The handles,
in particular, must be kept free of oil.
Checking the plastic housing
Carry out regular visual inspections of all parts of the
housing. If any parts are damaged, have them repaired
immediately and properly in MAKITA authorized service
centers.

Sharpening the saw chain

CAUTION:
Always withdraw the mains plug and wear safety
•
gloves when performing work on the saw chain.
Fig.30
Sharpen the saw chain when:
− Mealy sawdust is produced when damp wood is
cut;
− The chain penetrates the wood with difficulty, even
when heavy pressure is applied;
− The cutting edge is obviously damaged;
− The saw pulls to the left or right in the wood. The
reason for this behavior is uneven sharpening of
the saw chain, or damage to one side only.
Sharpen the saw chain frequently, but remove only
a little material each time.
Two or three strokes with a file are usually sufficient for
routine resharpening. When the saw chain has been
resharpened several times, have it sharpened in
MAKITA authorized service center.
Sharpening criteria:
− All cutter length must be equal. Cutters of differing
length prevent the chain from running smoothly,
and may cause the chain to break.
− Do not sharpen the chain once a minimum cutter
length of 3 mm has been reached. A new chain
must then be fitted.
when performing any
− The chip thickness is determined by the distance
between the depth gauge (round nose) and the
cutting edge.
− The best cutting results are obtained with following
distance between cutting edge and depth gauge.
Chain blade 91PX: 0.65 mm
Fig.31
WARNING:
An excessive distance increases the risk of kick-
•
back.
− The sharpening angle of 30 ° must be the same on
all cutters. Differences in angle cause the chain to
run roughly and unevenly, accelerate wear, and
lead to chain breaks.
− The side plate angle of the cutter is determined by
the depth of penetration of the round file. If the
specified file is used properly, the correct side
plate angle is produced automatically.
− Side plate angle for each saw chain are as follows:
Chain blade 91PX: 80 °
Fig.32
File and file guiding
− Use a special round file (optional accessory) for
saw chains to sharpen the chain. Normal round
files are not suitable.
− Diameter of the round file for each saw chain is as
follows:
Chain blade 91PX: 4.0 mm
− The file should only engage the cutter on the
forward stroke. Lift the file off the cutter on the
return stroke.
− Sharpen the shortest cutter first. Then the length
of this shortest cutter becomes the standard for all
other cutters on the saw chain.
Fig.33
− Guide the file as shown in the figure.
− The file can be guided more easily if a file holder
(optional accessory) is employed. The file holder
has markings for the correct sharpening angle of
30 ° (align the markings parallel to the saw chain)
and limits the depth of penetration (to 4/5 of the
file diameter).
Fig.34
− After sharpening the chain, check the height of the
depth gauge using the chain gauge tool (optional
accessory).
Fig.35
− Remove any projecting material, however small,
with a special flat file (optional accessory).
− Round off the front of the depth gauge again.
16