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SPINDLE
TURNING
Spindle
turning is the term applied to all work done on a lathe in which
the stock to be worked upon is held firmly between the live and
dead centers. There are two methods in common use in wood turning:
first, the scraping or pattern-makers' method; and second, the cutting
method. Each has its advantages and disadvantages, but it is necessary
that both be learned in order to develop a well rounded turner.
Care should be exercised, however, that each method be used in its
proper place. The first is slower, harder on the cutting edge of
tools, and less skill is required to obtain accurate work; the second
is faster, easier on the cutting edge of tools, and the accuracy
of results obtained depends upon the skill acquired. As skill is
the one thing most sought for in high school work, the use of the
cutting method is advocated entirely for all spindle turning and,
with but few exceptions, for face-plate and chuck turning.
TO
CENTER STOCK
If the
wood to be turned is square or rectangular in shape the best way
to locate the center is to draw diagonals across the end of the
stock. The point of intersection locates the center.
CLAMPING
STOCK IN THE LATHE
Take
the live center from the spindle and with a wooden mallet drive
the spur deep into the wood. Never drive the wood onto the live
center while in the spindle because serious injury may be done the
machine by such practice. When extremely hard wood is being used,
it is a good practice to make saw cuts along the diagonal lines
and bore a hole at the intersection, thus allowing the spur to enter
the wood more freely. Oil the other end of the wood while holding
it in a vertical position, and give the oil a chance to penetrate
into the wood. Then replace the live center by taking the stock
and center and forcing it into the spindle by a sudden push of the
hand. The tail stock is then moved about ½" to 1" from the end of
the piece to be turned, having the tail spindle well back in the
tail stock. The tail stock is then clamped to the lathe bed. Turn
the tail stock hand wheel until the wood is held firmly. Work the
cone pulley by hand at the same time, so that
the cup or dead center will be forced deeply into the wood, so deeply
that the live center will not continue to turn. Now turn the dead
spindle back until the live spindle begins to turn freely and clamp
the dead spindle fast.
Fig. 3
ADJUSTING
THE TOOL REST
Horizontally
the tool rest should be set about ⅛" from the farthest projecting
corner of the wood and should be readjusted occasionally as the
stock diminishes in size. The vertical height varies slightly according
to the height of the operator. It is even with the center of the
spindle for a short person; ⅛" above for a medium person;
and ¼" above for a tall person. So long as the stock is in its square
form the tool rest should never be adjusted while the machine is
in motion as there is danger of the rest catching the corners and
throwing the stock from the machine. Also see that everything is
clamped tight before starting the lathe.
POSITION
OF THE OPERATOR
The operator
stands firmly on the floor back far enough from the lathe to allow
him to pass the tools from right to left in front of his body without
changing the position of the feet. It may be
found convenient to turn slightly, bringing the left side of the
body a little closer to the lathe. In no case, however, should the
tools be brought in contact with the body as the cutting operation
from right to left should be accomplished by a movement of the arms
alone and not the swaying of the body. (Fig. 3.)
HOLDING
THE TOOLS
All tools
should be held firmly but not rigidly. The right hand should grasp
the handle at the extreme end for two reasons: first, to give as
much leverage as possible so that the tool will not be thrown from
the hands in case it should catch in the wood; second, a slight
wavering of the hand will not cause as much variance in the cuts
as when held closer up to the rest. The left hand should act as
a guide and should be held over the tool near the cutting edge.
The little finger and the back part of the palm of the hand should
touch the tool rest thus assuring a steady movement. The left hand
should not grasp the tool at any time. (Fig. 3.)
USE
OF THE TOOLS IN SPINDLE TURNING
The correct use of the
various tools used in spindle turning will be explained in detail
as the steps are worked out in the sequence of operations on the
exercises in the next chapter.
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