Dolmar PS-7900 - Manuel (Page 28)

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Files and how to work with them
Sharpen using a special file holder with a saw chain round
file. Normal round files are not appropriate for this work. See
"Accessories" for the order number.
File the first cutter half with a 7/32" (5.5 mm) dia. round saw-chain
file, then switch to a 3/16" (4.8 mm) dia. file.
The file should cut only when pushed forwards (arrow). Lift the
file when leading it backwards.
First sharpen the shortest cutter. The length of this cutter is then
the standerd for all other cutters of the chain.
New saw teeth must be filed to the exact same shape as the
used teeth, including on their running surfaces.
Always guide the file horizontally (10
° to the guide bar).
E
The file holder makes file guidance easier. It is marked for the
correct sharpening angle of 25° (keep the marks parallel with
the chain when filing, see illustration) and limits the cut depth
to the correct 4/5 of the file diameter. See "Accessories" for the
order number.
4/5
F
After having sharpened the chain, the height of the depth limiter
must be checked by means of a chain gauge. See "Accessories"
for the order number.
Correct even the smallest excess height with a special flat
file (1). See "Accessories" for the order number.
Round off the front of the depth limiter (2).
D
C
The sharpening angle of 25° must be identical for all cutters!
Different angles result in a roughly, irregularly running chain,
increase wear and tear and cause chain beakage.
The front rake 60° of the cutter results from the cut depth of
the round file. If the proper file is used in the right manner, the
correct front rake will be obtained automatically.
25°