Makita UC3520A Instruction Manual page 15

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. Should any parts be damaged, have them
repaired immediately and properly in a MAKITA
specialist repair shop.
Sharpening the saw chain
CAUTION:
Always withdraw the mains plug and wear safety
•
gloves when performing work on the saw chain.
Fig.26
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 behaviour 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 a
MAKITA specialist repair shop.
Sharpening criteria:
− All cutters must be of equal length (dimension a).
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.
− 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 a distance of 0.5 mm between cutting edge
and depth gauge.
Fig.27
WARNING:
An excessive distance increases the risk of
•
kick-back.
− The sharpening angle of 30 ° distance 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.
Fig.28
− The side plate angle of the cutter of 80 ° 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.
File and file guiding
− Use a special round file (optional accessory) for
saw chains, with a diameter of 4.5 mm, to sharpen
the chain. Normal round files are not suitable.
Fig.29
− The file should only engage the material on the
forward stroke. Lift the file off the material on the
return stroke.
− Sharpen the shortest cutter first. The length of this
cutter is then the gauge dimension for all other
cutters on the saw chain.
− 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.30
− After sharpening the chain, check the height of the
depth gauge using the chain gauge tool (optional
accessory).
Fig.31
− Remove any projecting material, however small,
with a special flat file (optional accessory).
− Round off the front of the depth gauge again.
Cleaning the guide bar and lubricating the
return sprocket
CAUTION:
Always wear safety gloves for this task. Burrs
•
present a risk of injury.
Fig.32
Check the running surfaces of the bar regularly for
damage. Clean using a suitable tool, and remove burrs if
necessary.
If the chain saw receives frequent use, lubricate the
return sprocket bearing at least once a week. Before
adding new fresh grease, carefully clean the 2 mm hole
on the tip of the guide bar, then force a small quantity of
multi-purpose grease (optional accessory) into the hole.
Cleaning the oil guide
Fig.33
− Clean the oil guide groove and the oil feed hole in
the bar at regular intervals.
New saw chains
Use two or three saw chains alternately, so that the saw
chain, sprocket and running surfaces of the bar wear
evenly.
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