{
L
f
)
All control levers are shown on
the
illustration on the opposite page.
Eiecukai
Controls.
A single panel,
on
the
front
of
the lathe,
contains all
the
electrical controls within easy reach
of
the
operator.
A Dush-button oneratedstarterwithoverload
and
no-voltprotection
is
~tandard
equip'ment
on
all machines;
other
controlsavailable being
two speed, reversing
and
coolant
pump
rotary type switches.
(b)
HeadstocK.
Speed changes should only
be
made when
the
spindle
is
stopped.
The
standard machine incorporates a start/stop
mechanical clutch and brake operated via a
third
shaft by control
levers adjacent to gearbox and apron.
An
alternative electrical
control by similar levers and
third
shaft provides direct reverse to
the
spindle
in
addition
to
forward
and
stop.
A tV\'o-position front gear lever selects
the
high speed range when
in
the
right-hand
position and
the
low speed range
in
the left-hand
position and this, used in conjunction with
the
two position twin
selectors at
the
top
of
the headstock, gives a total
of
eight spindle
speeds" Freely siiding gears combined
"Nith
a direct reading speed
chart ensures effortless and instantaneous speed change.
Forward
or reverse rotation
of
the
feed gear train
is
obtained
by
a selector lever at the front
of
the headstock.
(c)
Norton
Feed
Gear
box.
Thirty-six
changes
of
threads
and
feeds are obtained
by
manipulation
of
the
tumbler
lever
in
conjunc-
tionwith the nvo adjacent compoundgear levers.
The
lever positions
are determined by reference to the direct reading screwcutting
and
feed chart.
For
changewheei combinations see charts on page
12.
An
additional
unit
can be supplied giving lever operated selection
of
English or
Metric
threads. A range
of
I5
Metric
thread pitches
from
0"5
to 7 mm. together with the standard range
of
4 to
60
TPI
is
directly available.
With
the
metric gearbox, 30 metric pitches are available having a
range from
0"2
to
7 mm. pitch. Extra change wheels can be
supplied for Metric/English conversion giving a
thread
range
of
4 to 60
TPI.
Change Wheel combinations are given on page 13.
(d)
Apron.
Instantaneous engagement
and
disengagement to
both
feeds
is
obtained by
the
trip
lever
of
the
drop
Olit
worm box situated
at
the
base
of
the
apron.
The
feed selector knob which
is
directly
below
the
cross slide handwheel should be
pushed
in for sliding
feeds and pulled out for surfacing feeds.
Engagement
of
the
leadscrew for screwcutting is by means
of
the
lever
at
the right
of
the
apron wpich is pulled
up
for engagement
and
pushed down for disengagement. Simultaneous engagement
of
leadscrew and feed
rod
is
prevented
by
interlocking control.
The
carriage may be locked
to
the
bed
by means
of
the hexagon
screw on the
right-hand
side
of
the carriage.
Exact repeat
of
leadscrew engagement
is
obtained with the screw-
cutting
indicator.
On
English models:
To
cut
even threads
per
inch, engage at any graduation.
To
cut
odd
tf-....reads
per
inch, engage
at
any
numbered
graduation.
To
cut
haifrhreads
per
inch, engage
at
graduations I
or
3.
To
cut
quarte:
threads
per
inch, engage
at
graduation
I-
On
Metric
models:
To
cut
·5, ·75,
I,
l"5,
2,
3 and 6 mm. P. engage at any graduation.
To
cut
r·25, 2"5, 5
and
10
mm.
P.
engage at any
numbered
graduation.
To
cut
4 mm. P. engage
at
graduations
60
or
120.
The
indicator dial cannot be used for metric, B.A.
and
other
special threads when a 4
TPI
leadscrew
is
fitted.
It
can be used for metric threads (divisible into
120)
when a 6 mm.
pitch
leadscrew is fitted,
but
not
for special threads, including
English
and
American.
For
all speciai threads
it
is
necessary to
maintain engagement
of
leadscrew and an electrical reversing
switch can be supplied for returning the carriage, enabling repeat
cuts to be taken.
(e) Slideso Cross slide
and
compound slide are fitted with friction
grip micrometer dials graduated to read
"OOI
in.
The
compound
slide assembly
is
arranged
to
rotate
through
360 degrees
on
the
graduated cross slide
and
locking is by means
of
the
two
nuts
on
the
swivel slide.
Micrometer
dials are also available to read
0·02
mm.
(f)
TailstocKo Clamping to
the
bed
is
effected by
the
lever
at
the
rear
and
spindle, quill locking
is
by means
of
the
pad
bolton top
of
the
tailstock.
9
