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RECOMMENDED
SPEED
Always
follow
recommended
speed
to do spindle
turning
depending
upon
the size and length
of workpiece.
ROUGH
FINISH
SQUARE
LENGTH
RPM
RPM
to 2"
1 to 12"
1300
2000
to 2"
to 24"
1100
2000
to 2"
to 38"
1000
2000
2 to 4"
1 to 12"
1000
1800
2 to 4"
to 24"
900
1600
2 to 4"
to 38"
700
1400
4" Plus
1 to 12"
800
1400
4" Plus
to 24"
600
1100
4" Plus
to 38"
400
800
DUPLICATE
TURNINGS
Identical
turnings
require
great accuracy
when plotting
the
work and performing
the various
cuts. Many methods
have
been
devised
to aid in perfecting
the work.
Use of Patterns
Professional
workers
generally
use a pattern or layout board. This
is a thin piece of wood or cardboard
upon which is drawn a full-
size half section
of the turning. The contour of the finished surface
is drawn first. Then, the diameters
at various critical points are
drawn to scale as vertical lines intersecting
the contour line.
By placing
the pattern
against
the roughed-out
cylinder,
you
can quickly
mark
the various
points of the critical
diameters.
•
To make
each sizing
cut, use outside
calipers
and set
these
by actually
measuring
the length
of the vertical
lines
on the pattern
which
represent
the diameters
desired.
Make
the sizing
cut down
to the proper
diameter
by using
the calipers
to determine
when the cut is finished.
•
After making
the sizing cuts,
hang the pattern
behind
the
lathe where
it will serve
as a guide for completion
of the
workpiece.
Figure
50
Using
a Template
and a Diameter
Board
When
many identical
turnings
are to be produced,
it is conve-
nient to have a prepared
template.
This can be made
of thin
wood or cardboard,
it is cut on a band saw or scroll saw to
have the exact contour
or the finished
turning.
The number
one finished
turning
can also be used as a template.
Attach
the template
to a board and then mount
the board behind
the
lathe,
on hinges,
so that the template
can be moved
down to
touch
the workpiece
and allow you to closely
observe
progress
of your work.
If a great many turnings
are being produced,
a diameter
board
will save the time used for resetting calipers.
This is simply a thin
board along the edge of which a number
of semicircular
cuts
have been prepared
to represent
all the various
caliper settings
required
for measuring
the sizing cuts. Each semi-circular
cut is
held against
the workpiece
instead
of using the calipers.
Figure 51
Using
a Template
Using a Diameter
Board
LONG
SPINDLES
A long turning
can be worked
in short
sections,
with joints
arranged
to be at shoulders
where
they will not be noticed.
•
Long
thin work that is likely to whip
while turning
should
be
supported
at one or two places
by a backstick.
This is easy
to make. A simple
backstick
consists
of a short
length
of
wood mounted
vertically
in an extra
tool rest and notched
so that it can be used to support
the spindle
from behind.
An improved
type, which
uses 2 roller skate wheels
to form
the notch,
also is shown.
•
Position
the backstick
against
a pre-tumed
portion
near the
center
of the spindle,
this portion
being at least YJ' over finish
size to allow for later removal
of any marks
made upon it.
•
Operate
lathe at a slower
speed
than
normal.
Lubricate
the
workpiece
at point of contact
with the backstick.
Use
beeswax
(preferred),
lard or grease.
•
After completing
the turning,
remove
the backstick
and fin-
ish off the original
point of contact.
Sand off any slight
burns
remaining
on workpiece.
Figure 52 - Use of Backsticks
CUTTING
DOWELS
Dowels
of any size can be turned
quickly
with the simple
jig
shown.
If the stock is prepared
as a split or quartered
turning,
half round and quarter
rounds
will be produced.
The jig uses a _/2"gouge
as the cutting
tool and will produce
dowels
up to 7/_6"diameter.
Make the jig from suitable
hard-
wood stock
as shown.
•
The hole through
the jig must be large
enough
at the side
to the left of the gouge
to allow passage
of the square
stock. At the right of the gouge,
this hole must be just the
diameter
of the finished
dowel.
Make
the jig so that you
can hold and guide
it by hand.
•
To start,
center
the stock
like a spindle
turning
and turn
down about
2" at the right end to desired
size.
Figure 53
15
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