Clarke 6500685, Инструкция по эксплуатации и обслуживанию

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Either a cutting or scraping action can be used
when cutting at the circumference. The shaving
is removed like a peeling from a potato.
Scraping only, is used when cutting at the
diameter. The reason is obvious when you
consider that faceplate turning always requires
removal of wood across the grain. Wood does
not peel easily across the grain, and attempts
to use a cutting method will result in damage to
the work and throwing of the chisel by the work.
It follows that a cutting action is used for the
majority of spindle turning operations, whilst the
major ity faceplate tur ning is done by the
scraping method.
When a combination approach is to be used,
you will have to judge, by the feel of the work,
when to stop cutting and start scraping.
Never try to cut when it becomes difficult to hold
the chisel against the roughness of the wood
grain.
2.3 How To Position The Tool Rest for
Circumference Cutting
When cutting, the object is to pierce the outer
skin of wood to a certain desired depth, then to
hold the chisel steady, with the bevel edge
parallel to the work circumference, so that it will
peel off a shaving at this desired depth.
The only sure method of holding the chisel
steady is to rest the bevel against the work, as
shown in sketch 1.
When the tool rest is at
the proper height , the
chisel can be held with
the bevel pressed
against the work, and
the tool rest will act as a
fulcrum to support the
chisel against the
downward force of the
revolving work.
If the rest is placed too
low, so that the chisel is
held with the bevel out
from the work (Sketch
2), the cutting edge will
continue to dig deeper
into the work. It will dig
in until the “bite”
becomes so deep that
your hands have
difficulty holding the
14
chisel, then the
improper ly suppor ted
chisel will begin to
bounce, or chatter,
against the workpiece.
If the rest is placed too
low, the chisel must be
held extremely high to
position the bevel
against the work
(Sketch 3). Then the rest
loses most of its value as
a fulcrum, and the
downward force of the
revolving wor kpiece
tends to kick the chisel
back out of your hands.
If the rest is placed too
high, (Sketch 4) and the
chisel is correctly
positioned for cutting, it
strikes the workpiece
near the top where the
direction of force
exerted by the
workpiece is nearly
horizontal, and
kickback will again
result.
If the rest is placed too
far out from the work
surface (Sketch 5) then,
when correctly held,
the chisel is again too
high on the work. Also,
you have less leverage
on your side of the tool
rest, and it is even more
difficult to hold the
chisel.
With large diameter
work (Sketch 6), the tool
rest can be above the
workpiece centre line,
and somewhat out from
the work surface.
With small diameter
work (Sketch 7), the rest
should not be far from
the work surface. As
work grows smaller, the
rest should be
repositioned.