The new dominion. [volume] (Morgantown, W. Va.) 1876-1904, 1884-03-01
Huge Circular Saws.


Huge Circular Saws.
The largest circular saw that has been
sent out of this city recently was exact
ly six feet in diameter. 1t was ordered
by match company and went to Mich
igan. Fifty-two teeth projected from
its rim. 1t is now revolving at the rate
of 672 revolutions minute, and is cap
able of making a ten-inch to twelve
inch cut with each revolution. 1t can
saw off a forty-foot plank, therefore, in
an infinitesimal portion Of minute,
though as a matter of fact the frame on
which the logs are fed to saw is adj
justed to move at about the speed at
which man can walk. At that rate
there is nothing but whirr and a
shrek to announce the journey OF a
logs length. This is not solid saw or
it would have more than one hundred
teeth.
1t is one of the new patterns in
which the teeth are separated from the
plate and can be inserted and removed
at pleasure. The teeth in the sort of
saw of which tins monster is speci-
men are little curved bits of steel
pointed like chisels at the cutting end.
They fit into round sockets cut out of
the edges of the saw plates, and their
little chisel blades project slightly be-
yond the circle of the plate. There are
various inventions in movable teeth for
circular saws, and in nearly all of them
the circle plays an important part 1t
looks purely ornamental, but in reality
it prevents the steel from splitting with
the grain.
Solid saws continue to be made in
great numbers, but the inventors Of the
movable teeth, different patterns of
which are made by all saw manufact-
urers, are deriving fortunes, because
new teeth can be replaced for few
cents and in a few minutes, and the
body of the saw remains the size it was
made. whereas solid saws have to be
newly filed and set and sharpened
every time they dull, process that
consumes time and requires the services
of a sawyer whose skill commands
good wages. Every cutting reduces
the size of the saw. A sevcnty-two
inch saw is big one even in Michigan,
where the sixty-six inch saw is in COM
mon use There these five and half
foot saws are run at speed of from
500 to 700 revolutions in Norway pine
logs, and they cut as deep with each
revolution as the monster above de-
scribed. The little chisel-bit teeth will
chew out pine during a whole working
day, and an entire set of dull ones can
be replaced next day in five minutes
for three cents tooth. Some of the
rcf Af no
was sent from Michigan TO the cstab-
lishment Of a great sawmaker in this
city. 1t was esteemed a.s a curiosity
1t was not dust at all, but a mass of
little pellets of wood, three-eighths of
an inch in thickness. The lumbermen
prefer to waste lumber in this way pro-
vided they get speed out of their tools.
These huge saws are used singly in
saving rough log into planks. After
ward the planks are reduced to desired
widths by edger saws, which are
smaller implements revolving together
at the proper distances one from the
other.
A saw maker must know whether or
not his customer wants to run his pur-
chase at a high rate of speed before the
saw is made. Saw makers, in dcvel-
oping disk of steel into a saw, ham,
mer It so as to leave either hard or
soft center. A saw that has soft CEN
ter will wabble in the middle If per-
son takes hold Of it by the edge and
shakes it. If it has hard center one
part will not shake more than another.
A saw with hard center, if driven at
high rate of speed, will not cut
straight. Its edge will wabble. But
if it has soft center, and is sent
around at rate of 700 or 800 revolu-
tons minute, the centrifugal force
straining at the center stiffens the saw
and keeps the edge steady. To the av-
erage mind it would seem that there has
been the same straining after ornament
al effect in the vertical saws, so odd are
the shapes of the teeth. But here, again,
the study has been solely to produce
strength and cutting power. Some of
the vertical saws have duh teeth alter
mating with the sharp ones. The dull
ones do not reach out quite so far as the
cutters. Their purpose is to clear the
sawdust from before the cutters.-M.
Y. Sun. IS