WOOD TURNING
ADVANTAGES OF WOOD TURNING.--This is not, strictly, in the carpenter's
domain; but a knowledge of its use will be of great service in the
trade, and particularly in cabinet making. I urge the ingenious youth to
rig up a wood-turning lathe, for the reason that it is a tool easily
made and one which may be readily turned by foot, if other power is not
available.
SIMPLE TURNING LATHE.--A very simple turning lathe may be made by
following these instructions:
THE RAILS.--Procure two straight 2" × 4" scantling (A), four feet long,
and planed on all sides. Bore four 3/8-inch holes at each end, as shown,
and 10 inches from one end four more holes. A plan of these holes is
shown in B, where the exact spacing is indicated. Then prepare two
pieces 2" × 4" scantling (C), planed, 42 inches long, one end of each
being chamfered off, as at 2, and provided with four bolt holes. Ten
inches down, and on the same side, with the chamfer (2) is a cross gain
(3), the same angle as the chamfer. Midway between the cross gain (3)
and the lower end of the leg is a gain (4) in the edge, at right angles
to the cross gain (3).
THE LEGS.--Now prepare two legs (D) for the tail end of the frame, each
32 inches long, with a chamfer (5) at one end, and provided with four
bolt holes. At the lower end bore a bolt hole for the cross base piece.
This piece (E) is 4" × 4", 21 inches long, and has a bolt hole at each
end and one near the middle. The next piece (F) is 2" × 4", 14-1/2
inches long, provided with a rebate (6) at each end, to fit the cross
gains (4) of the legs (C). Near the middle is a journal block (7).
[Illustration: _Fig. 241. Frame details._]
CENTERING BLOCKS.--Next provide a 4" × 4" piece (G), 40 inches long,
through which bore a 3/4-inch hole (8), 2 inches from the upper end,
and four bolt holes at right angles to the shaft hole (8). Then, with a
saw split down this bearing, as shown at 9, to a point 4 inches from the
end. Ten inches below the upper end prepare two cross gains (10), each
an inch deep and four inches wide. In these gains are placed the top
rails (A), so the bolt holes in the gains (10) will coincide with the
bolt holes (11) in the piece A. Below the gains (10) this post has a
journal block (12), intended to be in line with the journal block (7) of
the piece F.
[Illustration: _Fig. 242. Tail Stock._]
Then make a block (H) 2" × 4", and 6 inches long. This also must have a
shaft hole (B), and a saw kerf (14), similar to the arrangement on the
upper end of the post (G); also bore four bolt holes, as shown. This
block rests between the upper ends of the lugs (C).
Another block (I), 2" × 4", and 6 feet long, with four bolt holes, will
be required for the tail end of the frame, to keep the rails (A) two
inches apart at that end.
THE TAIL STOCK.--This part of the structure is made of the following
described material:
Procure a scantling (J), planed, 4" × 4", 24 inches long, the upper end
of which is to be provided with four bolt holes, and a centering hole
(15). At the lower end of the piece is a slot (16) 8 inches long and
1-1/2 inches wide, and there are also two bolt holes bored transversely
through the piece to receive bolts for reinforcing the end.
A pair of cheekpieces (K), 2" × 4", and each 12 inches long, are mitered
at the ends, and each has four bolt holes by means of which the ends may
be bolted to the upright (J).
Then a step wedge (L) is made of 1-3/8" × 2" material, 10 inches long.
This has at least four steps (17), each step being 2 inches long. A
wedge 1-3/8 inches thick, 10 inches long, and tapering from 2 inches to
1-3/8 inches, completes the tail-stock.
THE TOOL REST.--This is the most difficult part of the whole lathe, as
it must be rigid, and so constructed that it has a revolvable motion as
well as being capable of a movement to and from the material in the
lathe.
Select a good 4" × 4" scantling (M), 14 inches long, as shown in Fig.
243. Two inches from one end cut a cross gain (I), 1-1/2 inches deep and
1 inch wide, and round off the upper edge, as at 2.
Then prepare a piece (N), 1 inch thick, 8 inches wide, and 10 inches
long. Round off the upper edge to form a nose, and midway between its
ends cut a cross gain 4 inches wide and 1-1/2 inches deep. The lower
margin may be cut away, at an angle on each side of the gain. All that
is necessary now is to make a block (O), 8 inches long, rounded on one
edge, and a wedge (P).
[Illustration: _Fig 243. Tool Rest._]
A leather belt or strap (Q), 1-1/2 inches wide, formed into a loop, as
shown in the perspective view (R), serves as a means for holding the
rest rigidly when the wedge is driven in.
MATERIALS.--Then procure the following bolts:
4-3/8" bolts, 10" long.
8-3/8" '' 6" ''
20-3/8" '' 5" ''
5-3/8" '' 9" ''
THE MANDREL.--A piece of steel tubing (S), No. 10 gage, 3/4 inch in
diameter, 11-1/2 inches long, will be required for the mandrel. Get a
blacksmith, if a machine shop is not convenient, to put a fixed center
(1) in one end, and a removable centering member (2) in the other end.
On this mandrel place a collar (3), held by a set screw, and alongside
of it a pair of pulleys, each 1-1/2 inches wide, one of them, being,
say, 2 inches in diameter, and the other 3 inches. This mandrel is held
in position by means of the posts of the frame which carry the split
journal bearings. This form of bearing will make a durable lathe, free
from chattering, as the bolts can be used for tightening the mandrel
whenever they wear.
[Illustration: _Fig. 244. Mandrel._]
The center point (1) is designed to rest against a metal plate (4)
bolted to the wooden post, as shown in the large drawing.
FLY-WHEEL.--It now remains only to provide a fly-wheel and treadle with
the communicating belt. The fly-wheel may be of any convenient size, or
it may be some discarded pulley or wheel. Suppose it is two feet in
diameter; then, as your small pulley is 2 inches in diameter, each
revolution of the large wheel makes twelve revolutions in the mandrel,
and you can readily turn the wheel eighty times a minute. In that case
your mandrel will revolve 960 revolutions per minute, which is ample
speed for your purposes.
The wheel should be mounted on a piece of 3/4-inch steel tubing, one end
having a crank 3 inches long. This crank is connected up by a pitman
rod, with the triangularly shaped treadle frame.
Such a lathe is easily made, as it requires but little metal or machine
work, and it is here described because it will be a pleasure for a boy
to make such a useful tool. What he needs is the proper plan and the
right dimensions to carry out the work, and his own ingenuity will make
the modifications suitable to his purpose.
The illustration (Fig. 245) shows such a lathe assembled ready for work.
THE TOOLS REQUIRED.--A few simple tools will complete an outfit capable
of doing a great variety of work. The illustration (Fig. 246) shows five
chisels, of which all other chisels are modifications.
A and B are both oblique firmer chisels, A being ground with a bevel on
one side only, and B with a bevel on each side.
C is a broad gage, with a hollow blade, and a curved cutting edge,
ground with a taper on the rounded side only.
D is a narrow gage similarly ground, and E is a V-shaped gage.
[Illustration: _Fig. 245._]
[Illustration: _Fig. 246._]
It may be observed that in wood-turning sharp tools are absolutely
necessary, hence a good oil stone, or several small, round and V-shaped
stones should be used.