Spindle Turnings; Cutting Coves (Convaves); Making Long Convex Cuts; Plotting The Shape - Craftsman 351.217150 Operator's Manual

Variable speed wood lathe
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B_evel Tangent ToWork
Start
Finish
Figure 46
CUTTING
COVES
(CONCAVES)
This is the most difficult
single
cut to master
- but one of the
most
important
in good
wood turning.
First,
use pencil
marks
to indicate
the edges.
Then, rough out the cove, to within about _/8"of the desired fin-
ished surface, by scraping
with the gouge
or round nose chis-
el. If the cove is to be very wide, sizing cuts can be made to
plot the roughing
out. Once it is roughed out, the cove can be
finished
in two cuts, one from each side to the bottom
center.
At the start
of either
cut, gouge
is held with
handle
high
and the two sides
of blade held between
the thumb
and
forefinger
of tool rest hand, just behind
the bevel.
Position
the fingers
so that they are ready
to roll the blade
into cove.
Hold blades so that bevel is at 90 ° angle to the work axis
with point touching
the pencil
line and pointed
into work axis.
From this start,
depress
point slightly
to start cut, then
con-
tinue to move point down in an arc toward
the bottom
cen-
ter cove - at the same time rolling
chisel
uniformly
so that,
at the end of the cut, it will be fiat at the bottom
of the
cove. The object
is to keep the extreme
point of gouge
doing the cutting
from start to finish.
Reverse
these
move-
ments
to cut the opposite
side.
Pencil Mark
Figure 47
Coves
also can be scraped
to finish
using the round
nose
chisel
or a rattail
file. These
methods
do not generally
pro-
duce perfectly
curved
coves.
MAKING
LONG
CONVEX
CUTS
First, turn work down to approximate
size, using
sizing cuts
(as required)
to determine
various
diameters.
Finish
cuts
can then
be made
with either
skew or gouge.
If the skew is used,
the principles
of the operation
are the
same
as those
employed
in cutting
a bead - except
that
the curve
is longer
and may be irregular.
Use the extreme
heel throughout
- start
at longer
end of curve
(if curve
is
irregular)
and progress
toward
steeper
end.
If gouge
is used,
make cut in the same
direction.
Start with
the handle
well back of point - swinging
handle
in the
direction
of tool travel to overtake
the point,
if necessary,
when the steep
part of the curve
is reached.
Object
is to
have the extreme
point doing
the cutting
throughout
with
the bevel as tangent
to curve
as possible.
Figure 48 - Chisel Inclined in Direction of Cut
MAKING
LONG
TAPER
CUTS
Long taper
cuts are made
like long convex
cuts, with the skew
or gouge.
However,
the angle
between
the cutting
edge
and
handle
is kept constant
during
the entire
cut. The handle
is
not swung
around.
Always
cut downhill.
Do not cut too deeply
at the center
of
the taper.
SPINDLE TURNINGS
PLOTTING
THE SHAPE
Once the basic
cuts have been
mastered,
you are ready
to
turn out finished
work.
The first step is to prepare
a plan for the proposed
turning.
This can be laid out on a suitable
sheet of paper. The lay-
out should
be to full size.
Next, prepare
the turning
stock by squaring
it up to the
size of the largest
square
or round section
in your
plan.
The stock
can be cut to the exact length
of the proposed
turning.
However,
in most cases,
it is best to leave the
stock a little long at one or both
ends to allow for trimming.
Mount
the stock
in the lathe
and rough it off to a maxi-
mum-size
cylinder.
2v4" I II
II
31/j' II IIIIl'/""JJ J11/Z'' Tenon
141/4 ''
Sizing
Cuts
Figure 49
Now, project
your plan onto the turning
by pencil
marking
the various
critical
dimensions
along
the length
of the spin-
die. These
dimensions
can be laid out with an ordinary
ruler or by using a template.
Make the pencil
marks
about
VZ' long so they will be visible
when
the work is revolved
under
power. The lines can be quickly
traced
around
the
spindle
by touching
each line with the pencil.
After
marking,
use the parting
tool to make sizing
cuts at
all of the important
shoulders.
When
learning,
you will find
it best to make
sizing cuts to accurately
plot the various
diameters.
Experienced
wood
workers
can manage
with
fewer
such cuts at the important
shoulders.
Plan each
sizing cut so that it is in waste
stock and make
each cut deep
enough
so that there will be just enough
wood
left under the cut for the finishing
process.
Once the sizing
cuts have been
completed,
rough-out
the
excess
wood with a gouge.
Then,
proceed
with the finish-
ing process
by making
the various
types
of cuts required.
14

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