User Manual

23
Sharpening the saw chain
Sharpen the saw chain when:
Mealy sawdust is produced when damp wood is cut; -
The chain penetrates the wood with difculty, 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 le are usually sufcient 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 - (A) must be equal. Cutters of different length prevent the
chain from running smoothly, and may cause the chain to break.
The chip thickness is determined by the distance between the depth gauge -
(round nose) and the cutting edge (B).
The best cutting results are obtained with following distance between cutting -
edge and depth gauge.
Chain blade 91VXL: 0.64 mm (0.025”)
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 le. If the specied le is used properly, the correct side plate angle
is produced automatically.
Proper angle for each saw chain are as follows: -
Chain blade 91VXL: 55°
File and le guiding
Use a special round le (optional accessory) for saw chains to sharpen the -
chain. Normal round les are not suitable.
Diameter of the round le for each saw chain is as follows: -
Chain blade 91VXL: 4.0 mm (5/32”)
The le should only engage the cutter on the forward stroke. Lift the le off -
the cutter on the return stroke.
Sharpen the shortest cutter rst. Then the length of this shortest cutter -
becomes the standard for all other cutters on the saw chain.
Guide the le as shown. -
The le can be guided more easily if a le holder (optional accessory) is -
employed. The le 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 le diameter).
After sharpening the chain, check the height of the depth gauge using the -
chain gauge tool (optional accessory).
Remove any projecting material, however small, with a special flat le -
(optional accessory).
Round off the front of the depth gauge again. -
B
A
55°
30°
90°
30
4/5