Replacing The Sprocket - Makita DUC302RF2 Instruction Manual

Cordless chain saw

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Table of Contents

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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 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.

—

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 90PX: 0.5 mm

Chain blade 91PX: 0.65 mm

Chain blade 25AP: 0.65 mm

► Fig.28: 1. Cutting length 2. Distance between

cutting edge and depth gauge 3. Minimum

3 mm

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 90PX: 75 °

Chain blade 91PX: 80 °

Chain blade 25AP: 85 °

► Fig.29: 1. Side plate angle

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 90PX: 4.5 mm

Chain blade 91PX: 4.0 mm

Chain blade 25AP: 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.30

—

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.31

—

After sharpening the chain, check the height of the

depth gauge using the chain gauge tool (optional

accessory).

► Fig.32

—

Remove any projecting material, however small,

with a special flat file (optional accessory).

—

Round off the front of the depth gauge again.

Cleaning guide bar

► Fig.33

Chips and sawdust will build up in the guide bar groove,

clogging it and impairing oil flow. Always clean out the chips

and sawdust when sharpening or replacing the saw chain.

Cleaning the oil discharge hole

Small dust or particles may be built up in the oil dis-

charge hole during operation.

Small dust or particles built up in the oil discharge hole

may impair the oil discharge flow and cause an insuffi-

cient lubrication on the whole saw chain.

When a poor chain oil delivery occurs at the top of

guide bar, clean the oil discharge hole as follows.

Remove the battery cartridge from the tool.

Remove the sprocket cover and saw chain from the

tool. (Refer to the section titled " Installing or removing

saw chain ".)

► Fig.34: 1. Slotted screwdriver

Remove the small dust or particles using a slotted

screwdriver with a slender shaft or the like.

Insert the battery cartridge into the tool.

Pull the switch trigger to flow built-up dust or particles

off the oil discharge hole by discharging chain oil.

Remove the battery cartridge from the tool.

Reinstall the sprocket cover and saw chain on the tool.