Logan 915 Instruction sheet

REVERSING

SWITCH

HEADSTOCK

•I

FIGURE

1-LOGAN

NO

.

920

FLOOR MODEL

11

" SWING QUICK CHANGE GEAR LATHE

2

.,

LOGAN

LATHES

The

cases

in

which

your

Logan

Quick

Change

Gear

Floor

Model

Lathe

is

delivered

contain

the

following:

l

Logan

Lathe

with

headstock.

tailstock.

and

carriage

mounted

on

the

lathe

bed

2-step V

type

motor

pulley

(screwed

to

base

of

lathe

crate)

Bag

tied

firmly to

lathe

bed

containing

l tool

post

tool

post

ring

l tool

post

screw

l tool

post

wedge

l tool

post

block

l tool

post

wrench

l

tailstock

wrench

2 60°

centers

l

Headstock

Adapter

Sleeve

l

knob

and

quill

Countershaft

assembly-floor

type

V Belt

(attached

to

countershaft)

Six

conductor

cable

(in

bag

attached

to

headstock)

Instruction

book

(inside

the

change

gear

guard)

Parts

List (inside

the

change

gear

guard)

Chip

pan

Set

of floor

legs

For

the

Bench

Model

Lathe

the

chip

pan

and

floor

legs

are

omitted

and

the

countershaft

assembly

will

be

the

bench

type

instead

of

the

floor

type.

Unpack

carefully

and

check

to

be

certain

that

you

have

removed

all

the

pieces.

After

removing

the

lathe

from

its

shipping

case,

clean

it

thoroughly

with

a stiff

brush

and

kerosene.

Then

cover

all

the

unpainted

surfaces

with

a film of

good

machine

oil to

prevent

rusting.

These

sur-

faces

should

be

covered

with

a film of oil

at

all

times

and

the

lathe

should

be

covered

with

canvas

when

not

in

use.

Setting

Up

the

Lathe

FLOOR MODEL.

Mount

the

lathe

on

the

chip

pan

and

the

floor

legs,

using

the

bolts

furnished,

and

attach

the

countershaft

assembly

to

the

rear

of

the

headstock

as

shown

in

Fig

.

2.

When

mo

unt

ing

t

he

l

athe

on

the

pan

and

legs,

notice

that

the

holes

in

the

pan

are

not

drilled

an

equal

distance

from

the

sides

of

the

pan

.

The

short

side

is

to

be

mounted

towards

the

back

of

the

lathe

to

keep

the

pan

from

interfering

with

the

motor.

Locate

the

lathe

on

a

solid

level

floor.

preferably

concrete

,

in

a

dry

well

lighted

location,

using

lag

screws

or

bolts

to

fasten

the

legs

to t

he

floor.

If

the

lathe

is

set

on

a con-

crete

floor,

mark

the

l

ocation

of

the

bolt

holes

and

drill

in

the

concrete

with

a

star

drill

setting

the

lag

screws

or

bolts

in

expansion

shields

or

in

melted

lead.

3

It

is

of

the

greatest

importance

that

the

lathe

be

level;

if

it

is

not. its

weight

will

cause

the

lathe

bed

to

be

twisted,

throwing

the

lathe

out

of true.

It

is

impossible

to

do

ac-

curate

work

on

a

lathe

that

is

not

level

and

the

lathe

will

be

damaged

beyond

repair.

When

the

lathe

is

in

position,

place

a

sensitive

machin-

ist's

level

on

top

of

the

lathe

bed

and

adjust

any

varia-

tion from

level

by

placing

thin

shims

under

the

feet.

Be

certain

the

lathe

is

level

across

the

ways

and

parallel

to

them,

both

at

the

headstock

and

tailstock

ends.

When

the

lathe

is

level

bolt

down

tightly

and

check

the

level-

ing

.

It

may

be

necessary

to

loosen

the

bolts

and add

more

shims

.

Remember

the

lathe

must

be

level

if it

is

to

perform

accurately.

BENCH MODEL.

Attach

the

countershaft

assembly

and

place

the

lathe

in

position

on

the

bench.

The

bench

for

the

lathe

should

be

31

to 33

inches

high

of

heavy

con-

struction

and

suitably

reinforced

for

steadiness

and

should

have

a

top

of

seasoned

wood

at

least

two

inches

thick.

We

suggest

that

the

top

either

be

doweled

or

that

4 or 5

steel

rods

with

end

nuts

be

run

crosswise

through

the

top

and

the

nuts

turned

tight.

pulling

the

boards

to-

gether.

Plane

the

bench

top

level

and

place

the

lathe

upon

it.

Mark

and

drill four

%-inch

holes

under

the

r.or-

responding

holes

in

the

legs

at

each

end

of

the

lathe.

Through

these

holes

place

four

machine

bolts

to

fasten

the

lathe

to

the

bench

and

to

aid

in

leveling.

Then

pro-

ceed

to

level

the

lathe

bed

with

shims

as

described

above

for

the

floor

model.

Mounting

the

Motor

The

Logan

Lathe

is

designed

to

be

powered

by

a 1750

RPM motor.

When

the

lathe

is

in

place

mount

the

motor

on

the

motor

bracket

beneath

the

countershaft.

Do

not

tighten

bolts

until

the

motor

position

has

been

adjusted.

To

adjust

the

motor

position,

align

motor

pulley

and

the

pulley

on

the

countershaft

by

moving

the

motor

until

the

two

are

in line.

Tighten

the

base

bolts,

but

do

not

place

the

belt

on

the

pulley

until

the

motor

wires

have

been

connected

and

the

motor

pulley

tested

for

direction

of rotation.

Connect

the

drum

revers

i

ng

switch

mounted

on

the

countershaft

with

the

motor

,

using

rubber

covered

6 con-

ductor

cable

in

accordance

with

the

wiring

diagram

pasted

on

the

inside

of

the

switch

cover.

Motors

furnished

by

Logan

have

a wiri

ng

diagram

packed

with

the

motor

to

assist

in

making

the

proper

connections.

Connect

the

motor

to

the

current

source.

The

motor

pulley

should

then

rotate

clockwise,

viewed

from

the

motor

pulley

end,

when

the

switch

is

in

the

forward

position.

Combined

switch

and

motor

wiring

diagrams

are

shown

on

the

last

page

of

this

booklet

for

use

with

the

motors

we

furnish.

We

recommend

the

use

of a

good

three

phase

motor

that

is

electrically

balanced

and

will

not

transmit

vibra

-

tion

through

the

belts

to

the

headstock,

causing

chatter.

Split

phase

motors

are

not

recommended

,

especially

where

fine

work

is

required.

Adiusting

the

Belts

The

belt

from

the

motor

to

the

countershaft

and

the

one

from

the

countershaft

to

the

lathe

are

easily

adjusted

for

tension

.

Neither

of

these

belts

should

be

too

tight.

the

tension

depending

on

the

load.

Excessive

belt

pressure

will

shorten

the

life of

the

belt,

place

a

strain

on

the

bearings

and

cause

a

loss

of

power

through

excessive

friction.

When

adjusted

for

normal

work

a

moderate

pressure

on

the

middle

of

either

belt

should

depress

it

about

l Y2

inches

.

The

motor

bracket

is

hinged

at

one

side

with

a

bolt

and

nut

adjustment

that

raises

or

lowers

it,

thereby

decreasing

or

increasing

the

tension

on

the

V belt.

The

V

belt

rides

in

a V

groove

of

the

two

step

motor

pulley

and

on

a flat

face

of

the

two

step

countershaft

pulley.

When

the

cone

pulley

guard

is

raised

,

the

countershaft

automatically

moves

toward

the

headstock,

thereby

releasing

the

tension

on

the

flat belt.

With

the

tension

released,

the

belt

may

be

easily

changed

from

one

step

to

another.

When

the

cone

pulley

guard

is

closed

the

belt

is

automatically

brought

into

tension

again

,

the

amount

of

tension

being

regulated

by

a

slotted

head

screw

located

at

the

rear

of

the

cone

pulley

guard.

Turning

the

screw

to

the

right

increases

the

belt

tension;

to

the

left

decreases

it.

The

Countershaft

The

countershaft

assembly

of

the

Logan

Lathe

is a

patented

development

that

is

a distinct

improvement

over

This

special

unit

assembly

is

carried

by

two

hinged

pins

attached

to a

bracke

t in

the

headstock

and

by

a

pedestal

to

the

floor

or

the

bench

giving

three

point

suspension

. To

prevent

vibration

being

transmitted

to

the

lathe

,

the

entire

assembly

is

insulated

by

rubber

at

all

points

of

contact.

The

two

hinge

pins

are

rubber

cushioned

and

the

cone

pulley

guard

rests

on

rubber

buttons.

Provision

is

made

to

adjust

belt

tension

4

GUARD

FOR

2-S

TE

P

ULL

E

YS

AND

V B

ELT

MOTOR CONTROl

SWITCH

RU

B

BE

R INS

ULATED

SU

PP

O

RT

GUARD

FOR

CO

NE

PULLE

YS

AND F

LAT

B

EL

T

RUBB

ER

TIPS

FIGURE

2-END

VIEW

OF COUNTERSHAFT ASSEMBLY

easily.

An

adjustable

motor

mounting

bracket

is

in-

cluded

in

the

assembly

. All

pulleys

and

belts

are

com

-

pletely

guarded,

yet

easily

accessible

. A

patented

tension

release

operates

automatically

when

the

cover

for

the

cone

pulleys

is

raised

to

permit

quickly

chang

-

ing

the

flat

belt

from

one

step

to

another.

And

finally

,

the

entire

assembly

is

designed

to

appear

as

a

stream-

lined

part

of

the

lathe.

Fig

. 2

above

illustrates

the

floor

model

lathe

and

countershaft

assembly

in

position

.

The

bench

model

uses

the

same

countershaft

design

adapted

for

bench

use

.

The

Headstock

The

headstock

of

the

Logan

Lathe

is

made

of

high

grade

gray

iron

and

is

totally

enclosed.

It

contains

the

headstock

spindle

and

bearings,

the

bull

gear,

the

cone

pulley

and

the

back

gears.

The

cone

pulley

is

turned

by

the

belt

from

the

countershaft,

and

thereby

turns

the

bull

gear,

or

transmits

its

power

through

the

back

gears

to

the

bull

gear

if

lower

speed

or

greater

power

are

desired.

High

carbon

mach

i

nery

steel

has

been

used

in

making

the

sp

i

ndle,

which

has

been

machined

and

ground

to a

fine finish.

The

nose

is

2¥4-in.

diam.

with

8-pitch

National

Form

threads.

~

MOTOR

DRIVE

GUARD

CONE

PINION

GEAR

FIGURE

3-HEADSTOCK

AND

COUNTERSHAFT

GUARD

CONE

COUNTERSHAFT

PUllEY

A

reducing

sleeve

permits

the

use

of a

No.2

Morse

Taper

Center.

The

1%-in.

hole

permits

work

as

large

as

l-in.

to

be

fed

through

the

spindle.

A

draw-in

collet

attach-

ment

taking

collets

up

to

l-inch

capacity

can

be

used

through

the

hollow

spindle.

The

spindle

is

mounted

on

two

New

Departure

precision

ball

bearings

which

are

sealed

in

grease.

The

use

of

ball

bearings

in

the

headstock

to

mount

the

spindle

is

advanced

design

that,

although

more

expensive,

gives

finer

results.

Ball

bearings

are

the

ideal

frictio.1

reducing

bearings-"nothing

rolls like a

ball."

Technical

advances

in

ball

bearing

manufacture

make

it

possible

now

to

obtain

special

pre-loaded

ball

bearings

of

extreme

pre-

cision

that

will

carry

the

loads

for

which

they

are

de-

signed

with

less

wear,

greater

accuracy

and

with

no

adjustment

required.

The

three-step

cone

pulley

and

the

cone

pmwn

gear

are

fastened

together

rigidly

and

revolve

freely

on

the

spindle.

For

direct

drive,

the

pulley

is

locked

to

the

large

bull

gear

which

is

keyed

to

the

spindle.

This

is

accom-

plished

by

means

of a

plunger-type

lock

located

on

the

side

of

the

bull

gear.

When

this

lock

is

"in"

the

pulley

turns

the

bull

gear

with

it;

when

"out"

the

pulley

and

the

cone

pinion

gear

turn

iree

of

the

bull

gear.

Should

it

ever

be

necessary

to

remove

the

headstock

spindle

the

following

procedure

should

be

followed_

First,

remove

the

take-up

nut.

the

spindle

gear,

Wood-

5

ruff

key,

collar,

and

bearing

grease

seal

in

the

order

named

from

the

left

hand

end

of

the

spindle.

Second,

remove

the

four fillister

head

screws

from

the

bearing

cap,

then

the

bearing

cap

and

grease

seal

from

the

right

hand

end

of

the

spindle.

Third,

loosen

the

set

screws

in

the

bull

gear

and

care-

fully

drive

the

spindle

with

a

wooden

mallet

toward

the

tailstock

end

of

the

lathe,

being

careful

to

hold

the

bull

gear

and

cone

pulley

parts

as

the

spindle

is

re-

moved

so

they

will

not

drop.

Important

Ball

bearings

can

be

ruined

by

improper

handling.

When

pressing

a

bearing

into

or

out

of

the

seat.

pressure

should

be

applied

to

the

outer

race

only,

but

when

pressed

on

to

or

off of

shaft,

pressure

should

be

applied

on

the

inner

race

only.

Bearings

should

be

carefully

kept

free of dirt

and

grit

and

except

in

extreme

cases

should

not

be

tapped

into

place

with

a he-mmer.

The

Back

Gears

FIGURE

4-BACK

GEAR DRIVE

The

back

gear

mechanism

on

the

Logan

Lathe

is

en-

closed

in

the

headstock

instead

of

being

located

in

an

exposed

position

as

in

the

usual

construction.

Also,

instead

of

having

to

reach

over

the

top

of

the

head-

stock

to

throw

a

back

gear

lever,

the

Logan

design

permits

controlling

the

back

gear

by

a

knob

on

the

front of

the

headstock.

The

back

gear

is

mounted

on

a

quill

which

turns

on

self-lubricating

bronze

bearings

on

an

eccentric

shaft.

The

knob

operates

a

rack

engaging

a

pinion

which

rotates

the

eccentric

shaft,

thereby

swing-

ing

the

back

gears

into

mesh.

When

the

knob

is

pulled

out,

the

back

gears

are

engaged

and

are

locked

in

posi-

tion

by

a

pawl

just

back

of

the

knob.

The

lock

is

released

by

pressing

the

pawl

with

the

finger.

The

cone

pulley

and

small

gear

turn

freely

on

the

spindle

and

are

locked

to

the

bull

gear

for

direct

drive

by

a

lock

located

in

the

side

of

the

bull

gear.

When

slower

turning

speed

or

greater

power

than

could

be

obtained

from a

direct

drive

is

required,

the

back

gears

are

used.

To

engage

the

back

gear

drive

first

pull

out

the

direct

drive

lock

so

that

the

cone

pulley

and

cone

pinion

gear

tum

free

of

the

bull

gear.

Then

engage

the

back

gears

so

that

the

power

is

transmitted

through

the

cone

pulley

and

cone

pinion

gear

to

the

large

back

gear,

and

from

the

small

back

gear

to

the

bull

gear.

The

bull

gear,

being

keyed

to

the

lathe

spindle,

turns

the

spindle.

Spindle

Speeds

MOTOR

COUNTERSHAFT

FIGURE

5-BELT

DRIVE

DIAGRAM

SPINDLE

OF

LATHE

The

following

table

shows

the

spindle

speeds

which

can

be

obtained

using

the

various

belt

positions

shown

in

Fig

.

5,

both

with

direct

drive

and

with

the

back

gear

drive.

Motor

Belt

Position

2

3

45

125

Spind

le Belt

Position

Back

Gear

Drive

Direct Belt

Drive

4 5 3 4 5

63 89 270 380 535

177 250 753 1060 1500

6

The

Lathe

Bed

The

bed

of

the

Logan

Lathe

is

an

extra

heavy

one-piece

casting

Df

hard

iron

containing

the

correct

proportion

of

steel

and

alloys

to

give

the

maximum

in

wear

and

to

withstand

all

strains.

Extra

width

(6-15 16"

across

SET

·

OYER

SCREWS

FIGURE

6-LATHE

BED

AND

TAILSTOCK

the

ways

)

extra

heavy

walls,

heavier

and

closer

spaced

box

type

cross

ribs

combine

to

give

greater

strength

and

a

more

solid

foundation

for

the

lathe

mechanisms.

The

accuracy

of

the

lathe

bed

and

the

ways

on

which

the

carriage

and

the

tailstock

are

mounted

is

of

primary

importance.

To

insure

extreme

accuracy

in

the

bed

two

prismatic

V-ways

and

two

flat

ways

are

employed.

They

have

been

planed,

milled

and

precision

ground,

giving

an

accurate,

heavy.

well

ribbed

bed

of

the

type

found

on

large

engine

lathes

.

In

order

to

retain

this

accuracy.

the

instructions

for

setting

up

the

lathe

emphasize

the

necessity

for

carefully

levelling

the

bed

both

across

and

parallel

to

the

ways.

With

proper

care

and

normal

use

there

will

be

no

appreciable

wear

on

the

bed

or

ways

of a

level

lathe,

but

the

surface

may

be

damaged

by

a

lack

of oil

or

by

abrasion

. Be

careful

not

to

drop

tools

or

work

on

the

ways

.

Keep

them

well

oiled

when

not

in

use,

wiping

them

off

and

re-oiling

before

continuing

work

and,

if

possible,

keeping

them

covered

during

filing

or

grind-

ing

operations.

STUD

LEfT

HAND

GEAR LEVER

THREADS

PER

INCH

48

A 7

2 4 A 8 9 10

11 11

Y2

12

13

14

24

B

16

18

20

22

23

24

26

28

2 4 c 3 2 3 6 4 0

44

4 6 4 8

52 56

24 D 6 4 7 2 8 0 8 8 9 2 9 6 1

04

112

24

E

128

144

160

176

184

192

208

224

LONGITUDINAL

TURNING

FEEDS

LEVER

POSITIONS

48

A .

1000

.

0888

.

0800

.0728

.

0696

.

0666

.0616

.

0572

IDLER

GEAR

24

A .

0500

.

0444

.

0400

.

0364

.

0348

.0333 .0308

.0286

24

8 .

0250

.

0222

.

0200

.

0182

.

0174

.

0166

.0154

.

0143

24

c

.0125

.

0111

.0100.0091 .0087.0083 .

0077

.

0072

24

D .

0062

.0055

.0050

.

0045

.

0043

.0041

.0038

.0036

24

E

.0031

.0027

.0025

.

0023

.

0021

.

0020

.

0019

.

0018

II II

II II II II II

FIGURE

7-THREAD

AND

FEED

CHART

ON

LOGAN QUICK CHANGE GEAR

LATHES

24

T

GEAR

IN

STUD

POS!TlON

!1'1

...

I

SCREW

GEAR

QUICK CHANGE

GEAR

LEVERS

feeding.

The

rate

of

feed

is

dependent

upon

the

speed

of

the

lead

screw.

It

is

necessary

in

operations

such

as

thread

cutting

to

set

the

rate

of

feed

in

a

definite

relationship

to

the

speed

of

the

spindle.

This

is

done

by

the

selection

of

gear

sizes

in

the

gear

train

together

with

the

setting

of

the

levers

on

the

quick

change

gear

box.

It

is

possible

to

obtain

48

different

threads

or

feeds

in

either

direction

on

the

Logan

Quick

Change

Gear

Lathe.

For

threads

from 8 to 224

per

inch,

inclusive,

the

change

gear

train

is

set

up

as

in

Fig. 8,

using

the

24

tooth

stud

gear.

A 48

tooth

gear

is

mounted

as

a

spacer

on

the

idler

gear

but

serves

no

active

purpose.

For

threads

from

4 to 7

per

inch

the

48

tooth

gear

is

mounted

in

the

stud

gear

position

and

the

24

tooth

gear

is

mounted

as

a

spacer

on

the

idler

gear.

FIGURE

8-CHANGE

GEAR TRAIN

ON

LOGAN QUICK CHANGE GEAR

LATHE

All

other

adjustment

for

the

various

thread

or

feed

re-

quirements

is

made

by

the

two

levers

on

the

quick

change

gear

box. Fig. 7

shows

a

reproduction

of

the

thread

and

feed

chart

mounted

on

the

gear

box

.

As

an

example,

assume

that

the

24

tooth

stud

gear

is

engaged

in

the

change

gear

train

(with

the

48

tooth

stud

gear

being

used

as

a

spacer)

and

that

it

is

required

to

cut

18

threads

per

inch

.

Locate

18

on

the

gear

chart.

Set

the

left

hand

lever

in

position

"B"

as

indicated

and

set

the

right

hand

lever

directly

under

the

column

in

which

18

appears.

Similarly,

if a

longitudinal

feed

of .0045

inches

per

revolution

d

the

spindle

is

required,

set

the

left

hand

lever

in

position

"D"

and

the

right

hand

lever

under

the

column

in

which

.0045

appears.

Power

Feeds

The

left

end

of

the

headstock

spindle

is

fitted

with

a

gear

for

the

transmission

of

spindle

power

through

a

gear

train

and

through

the

quick

change

gear

box

to

the

lead

screw

along

the

front of

the

lathe

which

is

used

in

power

7

Power

cross

feeds

are

.25

times

the

chart

figures

shown

for

power

longitudinal

feed.

The

feed

reversing

lever,

which

extends

from

the

gear

train

housing

has

three

positions-Up,

Down

,

and

Center.

When

in

the

center

position

the

two

gears

on

the

end

of

the

lever,

which

turn

on

bronze

bearings,

are

free

of

the

gear

train

and

all

power

feeds

are

disconnected.

When

"Up;'

the

lead

screw

turns

to

move

the

longitudinal

and

cross

feeds

in

one

direction

.

When

"Down:·

the

longi-

tudinal

and

cross

feeds

are

in

the

opposite

direction

.

The

alloy

steel

lead

screw

which

runs

along

the

front of

the

lathe

bed

has

an

Acme

thread

accurately

cut

with a

pitch

of 1

/a

inch

(8

threads

to

an

inch

)

and

is

mounted

at

each

end

in

a

bearing.

Clean

and

oil

the

lead

screw

frequently

to

maintain

its

accuracy.

The

Tailstock

The

tailstock

slides

on

a V

and

flat

way

0f

the

bed

as

illustrated

in

Fig.

6.

It

is

locked

in

position

along

the

bed

by

tightening

the

clamp

bolt

with

the

clamp

bolt

wrench

furnished

with

the

lathe.

The

tailstock

spindle

is

controlled

by

the

tailstock

hand

wheel.

Turning

the

wheel

in

a

clockwise

direction

brings

the

spindle

out

of

the

tailstock.

The

spindle

is

of

specia

l

steel

with

a

ground

finish

and

has

been

reamed

for a

No. 2

Morse

Taper

Center,

which

may

be

ejected

by

turning

the

tailstock

wheel

in

a

counter

clockwise

direc-

tion

until

the

spindle

reaches

the

end

of its

travel.

The

spindle

is

graduated

up

to 4

inches

in

sixteenth

inch

graduations

for

accuracy

in

boring

and

drilling.

Lock

spindle

in

place

by

turning

the

binding

lever

to

the

right. A

cup

and

quill

are

mounted

on

the

top

of

the

tuilstock. Fill

with

a

heavy

grease

or

a

mixture

of

white

lead

and

machine

oil to

be

used

to

lubricate

the

centers

when

work

is

mounted

between

them.

The

tailstock

may

be

set-over

11

'

16

inch

for

turning

tapers

by

loosening

the

tailstock

clamp

nut

and

adjust-

ing

the

headless

set

screws

located

on

either

side

.

To

align

the

tailstock

again

the

index

line

on

the

tail

stock

and

tailstock

base

will

indicate

the

approximate

posi-

ion.

To

obtain

the

exact

position

it

is

necessary

to

place

a

12

or

15

inch

check

bar

between

centers

.

Take

a

light

cut,

then

check

the

diameter

at

each

end

of

the

bar

with

a

micrometer.

If

there

is

a

variation

adjust

the

set-over

screws

until

the

diameters

at

each

end

are

the

same

after

a cut.

Lathe

Centers

The

headstock

spindle

is

ground

to

take

a

special

adapter

8

for a No. 2

Morse

Taper

Center.

The

tailstock

is

fitted

for a No. 2

Morse

Taper

Center.

FIGURE

9-60

DEGREE

C.ENTER

While

the

tailstock

spindle

should

be

kept

oiled

on

the

outside,

the

interior

should

be

dry

and

clean.

Be-

fore

placing

either

of

the

centers

in

the

lathe,

they

and

the

tapers

into

which

they

fit

should

be

wiped

free

of

oil

and

dirt, for

the

presence

of a bit of dirt

or

a

slight

film of oil will

interfere

with

the

accuracy.

HAND CROSS

F

EE

D

APRON

The

Carriage

FR

IG

ION

Cl

UTC

H POW

ER

FEED

LE

V

ER

FIGURE

1

0-CARRIAGE

The

carriage

of

the

lathe

is

made

up

of four

parts,

the

apron

assembly,

the

saddle

assembly,

the

compound

rest

assembly

and

the

tool

post

assembly.

Since

the

carriage

supports

the

cutting

tool

and

controls

its

action

it

is

an

important

unit.

APRON.

The

apron

which

is

suspended

from

the

front

of

the

saddle

contains

the

power

feed

mechanism

and

the

long

i

tudinal

hand

feed

together

with

the

threading

dial.

The

large

hand

feed

whee

l

on

the

front of

the

apron

moves

the

carriage

along

the

ways

by

means

of

gears

which

engage

a

rack

on

the

unders

i

de

of

the

front

way

.

The

powe

r

feed

l

ev

er

is l

ocated

in

the

center

of tl:e

apron

and

can

be

se

t in

th

ree

pos

iti

ons

.

When

"Up;'

the

apron

mechanism

is

set

for

power

longitudinal

feed;

when

"Down

:· for

power

cross

feed

,

and

when

in

the

central

position,

is

in

neutral.

To

engage

the

power

after

having

set

the

power

feed

lever

in

the

required

position,

the

fric-

tion

clutch

knob

located

immediately

below

is

turned

to

the

right.

Similarly,

it

is

turned

to

the

left to

disengage.

The

feed

reverse

lever

on

the

headstock

controls

left

or

right

longitudinal

feed,

and

forward

and

backward

move-

ment

of

cross

feed.

In

thread

cutting,

the

half

nuts

are

used

for

longitudinal

feed.

The

half

nut

lever

is

located

at

the

right

side

of

the

apron.

The

half

nuts

can

only

be

engaged

when

the

power

feed

lever

is

in

the

neutral

position,

and

also

the

power

feed

lever

cannot

be

engaged

while

the

half

nuts

are

engaged.

Power

is

fed

through

the

friction

drive

from

the

spline

in

the

lead

screw,

whereas

the

half

nuts

drive

from

the

lead

screw

thread

.

To

minimize

wear

and

thereby

retain

the

accuracy

of

the

half

nuts

and

lead

screw,

they

should

only

be

used

for

thread

cutting

.

The

threading

dial

on

the

right

end

of

the

apron

indicates

the

proper

position

in

which

to

engage

the

half-nuf

lever

during

threading

operations

so

that

the

tool

will

enter

the

same

groove

for

each

cut,

thereby

eliminating

the

need

for

reversing

the

drive

at

the

end

of

each

cut.

(Fig.

ll

Threading

Dial.)

When

cutting

even

numbered

threads,

the

half

nuts

may

be

engaged

at

any

point

on

the

threading

dial.

When

cutting

odd-numbered

threads

(5,

7,

9,

ll,

etc.

per

inch),

engage

the

half-nut

lever

when

the

outer

mark

is

in

line

with

either

the

mark

numbered

'T'

or

that

numbered

"2:'

When

cutting

half-numbered

threads

(

4Y2,

SY2,

6Y

2,

ll

Y2,

etc.).

engage

the

half-nut

lever

at

the

same

point

on

the

dial

for

each

cut.

The

saddle,

which

moves

longitudinally

on

the

front

V-way

and

the

back

flat

way,

has

been

machined

from

a

semi-steel

casting,

and

is

held

down

on

the

bed

by

gibs

which

bear

on

the

underside

of

the

front

and

back

ways.

These

gibs

are

adjustable

and

should

be

set

just

tight

enough

to

give

a fi

rm

sliding

fit

between

the

car-

riage

and

the

bed.

The

compound

rest

base

moves

across

the

top

of

the

.saddle

on

dovetailed

ways

to

form

the

cross

slide.

The

hand

cross

feed

is

operated

by

a

hand

wheel

at

the

end

of

the

cross

feed

slide.

This

slide

is

equipped

with

a

gib

which

may

be

ti

ghtened

by

adjustment

of

the

set

screws

on

the

outs

i

de

of

th

e sli

de.

The

cross

feed

gib

should

fit

snugly

and

shou

ld

be

adj

us

t

ed

whenever

play

develops.

The

cross

slide

is

moved

by

an

Acme

threaded

screw

mounted

in

self

lubricating

bronze

bearings

.

The

hand

wheel

of

the

cross

feed

is

of

polished

steel

and

is

cali-

brated

in

thousandths

of

an

inch

for

measurement

of

feed

when

a

defin

i

te

cu

t

is

to

be

taken

.

9

The

compound

rest

is

mounted

on

top

of

the

cross-slide

on

a

base

calibrated

in

degrees

from 0°

to

90°

in

both

directions

. Two

screws

with

tapered

plugs,

one

on

each

side

of

the

rest,

hold

the

base

in

position,

and

by

loosen-

ing

these

screws

the

rest

may

be

swivelled

to

the

de-

sired

angle

. Two

self-lubricating

bronze

bearings

are

mounted

in

the

bushings

of

the

rest

which

is

moved

over

the

slides

by

an

Acme

threaded

screw.

The

slide

is

dove-

tailed

with

qib

take-up

for

wear.

FIGURE

11-THREADING DIAL

The

compound

rest

motion

is

controlled

from

a

hand

wheel

by

which

the

tool

may

be

moved

into

the

work

for

short

tapers

.

The

compound

rest

handle

is

cali-

brated

for

measurement

in

thousandths

of

an

inch.

The

tool

post

fits

into

a T slot

in

the

compound

rest

and

holds

the

tool

holder

by

means

of a

square

head

screw.

Oiling

the

Lathe

The

design

of

the

Logan

Lathe

provides

for

correct

lubrication

with

a

minimum

of

attention

.

The

ball

bear-

ings

in

the

headstock

are

sealed

in

grease

and

require

no

further

lubrication

for

the

life of

the

bearing.

At

31

separate

points

there

are

self-lubricating

bronze

bearings,

where

in

ordinary

construction

plain

bearings

with

oil

holes

are

used

.

The

bronze

in

these

bearings

is

of

an

absorbent

texture

and

has

been

thoroughly

im-

pregnated

with

lubricant.

The

correct

film of

lubricant

is

constantly

maintained

at

the

bearing

surface

without

the

necessity

of

frequent

renewal.

Those

points

in

the

lathe

requiring

regular

lubrication

should

be

gone

over

every

time

the

lathe

is

used

and

in

a

definite

order

so

that

no

parts

will

be

missed

.

Use

a

good

machine

oil

no

heavier

than

SAE No.

10,

wiping

away

excess

oil

that

would

cause

dirt to

adhere

to

the

l

athe

. Do

not

attempt

to oil

the

lathe

while

it

is

running.

6

FIGURE

12-0ILING

DIAGRAM

Using a

long-spouted

can,

oil

the

following

points

each

time

the

lathe

is

used:

1.-2.

Two oil

cups

on

top

of

the

countershaft

bearings.

3.

The

spring

well

on

top

of

the

tailstock

.

4.

One

oil

cup

on

top

of

the

bearing

at

right

end

of

the

lead

screw.

5.

The

feed

reverse

lever.

(A

hole

has

been

drilled

in

the

base

of

the

lever

to

receive

oil.)

6.

The

bearings

on

each

of

the

change

gears.

7.

The

spindle

pulley

.

(Remove

the

headless

set

screw

on

the

3econd

step

of

the

pulley

and

oil

freely

before

using

the

back

gears.)

8.

Remove

set

screw

and

fill this oil ·

well

so

that

when

petcock

set

screw

(9)

is

removed,

oil

just

drips

out.

10

Keep

the

following

surfaces

clean,

free

of

chips

and

covered

with

a film

of

oil:

The

lead

screw.

The

cross

slide.

The

compound

slide.

The

lathe

bed

ways,

both

V

and

flat.

The

outside

of

the

tailstock

ram.

Spindle

taper

~rea.

A

small

amount

of

graphite

grease

should

be

kept

on

the

teeth

of

all

gears

in

the

headstock,

the

apron

and

on

the

teeth

of

the

rack

on

the

underside

of

the

front

way.

Lathe

Belts

The

Logan

Lathe

is

delivered

equipped

with

a flat

belt

of

web

and

rubber

composition

connecting

the

cone

pulley

on

the

lathe

with

the

countershaft.

A V Belt

is

also

furnished

to

connect

the

2

step

V

groove

motor

pulley

with

the

2

step

flat

face

pulley

on

the

counter-

shaft.

The

life

and

efficiency

of

both

these

belts

will

be

increased

by

keeping

them

clean

and

free

from oil

and

by

slipping

them

off

the

pulleys

to

release

the

tension,

if

the

lathe

is

to

be

unused

for

any

considerable

length

of time.

The

use

of a flat

belt

makes

removal

of

the

spindle

unnecessary

when

replacing

or

changing

the

belt

pro-

viding

an

endless

belt

is

not

required.

This

arrangement

has

two

distinct

advantages.

First.

the

belt

may

be

changed

quickly

and

easily

with

a

minimum

of effort.

for it

may

be

laced,

glued

or

hooked

on

the

spindle,

a

simple

procedure

when

compared

with

the

task

of

removing

the

spindle

and

slipping

an

endless

belt

over

it.

Second,

there

is

no

risk

of

losing

the

alignment

that

has

been

accurately

achieved

at

the

factory

through

the

use

of

precision

gauges.

Because

of

the

high

grade

materials

used

and

the

accurate

workmanship

in

assembling

the

headstock,

under

ordinary

circumstances

it

need

not

be

taken

apart

during

the

life of

the

lathe.

However,

should

you

desire

to

remove

the

spindle,

you

may

do

so,

as

was

explained

in

the

spindle

description

.

FIGURE

13-LACED

BELT

Fastening

the

flat

belt

over

the

spindle

pulley

is

a

simple

matter

and

may

be

done

in

any

one

of

the

following

ways.

The

belt, if

laced,

may

be

joined

by

either

gut

or

rawhide

throngs

as

follows.

When

the

belting

has

been

cut

to

the

desired

length,

square

the

ends

and

punch

ten

holes

as

shown

in

Figure

13.

Start

the

lace

through

holes

A

and

B,

pulling

both

ends

through,

working

one

to

the

right

and

one

to

the

left,

as

shown.

Do

not

cross

one

layer

of

lacing

over

another

on

the

pulley

side

and

do

not

allow

it

to

kink

or

turn

or

the

belt

will

not

run

smoothly.

Fasten

the

ends

as

shown.

If

round

gut

is

used

cut

shallow

trenches

between

the

holes

on

the

pulley

side

and

sink

the

gut

in

them.

II

PULLEY

SIDE

FIGURE

13A-GLUED

BELT

If

the

belt

is

to

be

glued,

make

allowance

for over-

lap

and

taper

the

overlap

at

each

end

so

that

ends

will

join

as

shown.

See

Figure

13A.

Double

belts

should

be

split

and

each

part

tapered.

Full

directions

are

usually

supplied

with

the

glue;

follow

carefully.

..-----

--

..-,-.-

-·-·

FIGURE

13B-BELT HOOK

The

simplest

and

quickest

method

of

fastening

belt

ends

is

by

means

of

wire

hooks,

as

shown

in

Figure

l3B

above.

A

number

of different

types

are

available

which

are

easily

attached

by

forcing

the

ends

of

the

hooks

through

the

belting

and

folding

them

over.

The

V Belt

supplied

is

a

standard

lf2

inch

endless

belt

which

is

easily

slipped

into

place

over

both

the

two

step

V

motor

pulley

and

the

2

step

flat

face

counter-

shaft

pulley.

Cutting Tools

There

are

a

great

variety

of

c~tting

tools

used

on

a

lathe

;

each

shape

being

adapted

to

the

work

to

be

done

and

the

finish to

be

left

on

the

metal.

Basically,

however,

all

employ

the

same

principle

for

all

operate

with

a

tearing

action.

The

cutting

edge

of

the

tool

tears

a

chip

from

the

work

and

breaks

it

into

separate

sec-

tions

as

shown

in

Picture

14.

.

I

Left

Hand

Turning

Tool

Round

Nose

Turning

Tool

Threading

Tool

Cut-Off

Tool"

Top

and

Side

View

)

f8.3o"

71

11

~IS"

l

E

)

1

t 1

?2

LATHE TOOL BIT SHAPES

Top

View

Working

Position

FIGURE

17

12

Side

View

Working

Position

Grinding

Angles

Back

Rake

Angle

______

__

_j

61

/2

o

Front

Clearance

Angle

..

7°

Side

Rake

Angle

_____

___

_18

°

Side

Clearance

Angle

..

8°

Lip

Angle

_____________

64

°

Back

Rax.,

Angle

_____

_16'12

°

Front

Clearance

Angle

..

7°

Side

Rake

Angle

__

_

________

_18

o

Side

Clearance

Angle

.... 8°

Lip

Angle

----------------

--------

64 o

Back

Rake

Angle

__________

16

1

~

0

Front

Clearance

Angle

..

7°

Side

Rake

Angle

_

_18

o

Side

Clearance

Angle

.... 8°

Lip

Angle

·······-·-···

___

64

°

Back

Rake

Angle

__________

16

1

/

2'

Front

Clearance

Angle

..

7°

Side

Rake

Angle

----·

··-

-

··

_18

°

Side

Clearance

Angle

.... 8°

Lip

Angle

······-···--------------64

'

Back

Rake

Angle

__________

16'12 o

Front

Clearance

Angle

_ 7°

Side

Rake

Angle

--·--------

·· oo

Side

C'earance

Angle

___

8°

Lipe

AnJle

--·------------------

82

°

Back

Rake

Angle

____________

0°

Front

Clearance

Angle

_ 5o

Side

Rake

Angle

______

_

______

0°

Side

Clearance

Angle

.. 10°

Lip

Angle

-----------------------

80°

Back

Rake

Angle

___________

0°

Front

Clearance

Angle

_ 5o

Side

Rake

Angle

..

________

o

o-

Side

Clearance

Angle

.

..

3°

FIGURE

14-CUTTING

ACTION

OF

TOOL

BIT

Because

of this

the

cutting

edge

of

the

tool

must

be

sharp

enough

to

separate

the

chip

from

the

work

with

a

minimum

of

power,

but

must

also

be

large

enough

to

support

the

cutting

surface

and

to

carry

the

heat

of

friction

away

from

the

point.

These

two

opposiflg

requirements

can

be

accomplished

by

carefully

work-

ing

out

the

angle

at

which

the

tool will

enter

the

work

and

the

angles

of

clearance

between

the

tool

and

the

work.

SIDE

RAKC.

ANGLE

CLEARANCE

ANGl-E:

(FRONT

C

LEARANCE

ANGLE:

FIGURE

15-CUTTING

ANGLES

Figure

15

above

illustrates

a

cross-section

and

a

side

view

of a tool bit

in

working

position

showing

the

names

of

the

various

angles

for

grinding

and

setting

the

bit.

For

efficient

performance,

each

of

the

angles

and

set-

tings

shown

should

be

specially

determined

for

the

particular

kind

of

material

being

worked

on

,

the

mate-

rial

the

tool bit

is

made

from,

the

cuttmg

speed,

the

kind

of

coolant

being

used,

if

any,

and

whether

rough-

ing, finishing,

parting

or

forming

work

is

being

done.

Figure

17

illustrates

the

seven

bit

shapes

commonly

used

and

the

working

position

of

each

with

the

correct

angles

for

an

average

cut

in

mild

steel

at

a

cutting

speed

of 80 feet

per

minute

using

high

speed

tool

steel

bits

and

machining

without

coolant.

In

shaping

the

bits

use

a

good

medium

grit

grinding

wheel

being

careful

not

to

burn

the

edges

.

Cool

the

bit

in

water

to

prevent

drawing

the

temper.

FIGURE

16-TOOL

HOLDER

A tool bit

holder

for

holding

1

/4-

by

1

/4-

inch

tool

bits

eliminates

the

use

of

large

and

more

expensive

tools of

high

speed

steel

and

also

holds

the

bit

at

an

angle.

13

This

angle

directs

a

large

portion

of

the

cutting

pressure

directly

toward

the

base

of

the

tool post.

When

using

the

tool

holder,

the

cutting

end

of

the

bit

should

be

clamped

as

close

to

the

end

of

the

holder

as

possible

and

the

bit

holding

end

of

the

holder

should

be

as

close

to

the

tool

post

as

possible.

This will

give

the

cutting

edge

rigid

support

so

that

the

action

of

the

work

will

not

force it

downward,

causing

chatter

and

possibly

breaking

off

the

bit.

Holding

the

Work

There

are

five

common

methods

of

holding

work

in

a

lathe;

between

centers,

in

a

chuck,

on

the

face

plate,

in

a collet,

and

on

a

mandrel.

MOUNTING

BETWEEN

CENTERS

Whenever

possible

the

work

is

turned

between

centers

as

this

method

is

most

accurate

and

permits

removing

the

work

from

the

lathe

and

replacing

it

without

affect-

~

ling

the

accuracy.

The

first

step

in

turning

between

centers

1s

to f\nd

the

center

of

the

ends

of

the

work

and

drill

center

holes.

This

operation

is

important

and

should

be

done

with

care.

If

square,

hexagonal.

or

any

other

regular

sided

stock

is

used

lines

may

be

scribed

across

the

ends

from

corner

to

corner,

the

point

of

intersection

being

the

center.

FIGURE

18-FINDING

CENTERS

8

0

If

round

stock

is

used

the

center

may

be

found

either

with

dividers

or

with

hermaphrodite

calipers.

When

using

dividers

open

them

to

approximately

half

the

diameter,

and

laying

the

stock

on

a flat

surface

place

one

point

on

the

work,

the

other

on

the

flat

surface,

and

scribe

a

line

along

the

end

as

shown

in

Fig. 18.

Turn

the

stock

a

quarter

turn

and

scribe

another

line

and

so

on

until

the

four

lines

are

drawn

as

shown.

If

the

dividers

are

held

at

the

same

angle

each

time,

the

center

of

the

small

square

formed

will

be

the

center

of

the

stock.

If

hermaphrodite

.

calipers

are

used

open

them

to ap-

proximately

half

the

diameter

of

the

stock

and

holding

the

bent

leg

on

four

quarter

points

of

the

circumference,

scribe

four

arcs

across

the

end,

forming a four-sided

central

figure.

The

center

of this figure will

be

the

center

of

the

stock.

Rubbing

chalk

on

the

ends

will

make

the

scribing

more

easily

seen.

When

the

center

of

the

stock

has

been

found,

place

a

center

punch

vertically

on

the

center

mark

and

strike

with

a

hammer,

making

an

indentation

sufficiently

deep

so

that

the

work

will

revolve

on

the

center

points

of

the

lathe.

The

stock,

especially

if

close

to finish size,

should

be

placed

in

the

lathe

and

the

center

tested

before

counter-

sin~ing_.

!his

is

done

by

revolving

the

stock

by

hand

~h1le

1t

IS

held

between

the

centers

and

holding

a

p1ece of

chalk

so

that

it will

touch

any

high

spots

on

the

work

If

the

chalk

encounters

high

spots

move

the

center

holes

toward

these

high

spots

by

placing

the

work

in

a

vise

and

driving

the

center

punch

toward

them

at

an

angle,

then

bringing

it

back

to a

vertical

position.

The

countersink

drill is

usually

used

in

drilling

center

holes

since

it

both

drills

the

hole

to

the

proper

depth

and

countersinks

at

the

proper

angle.

CHUCK

WORK

TAILSTOCK

FIGURE

20-COUNTERSINKING

CENTERS

The

countersink

drill is

mounted

in

a

chuck

in

the

headstock

spindle

and

the

work

held

with

the

tailstock

center

in

one

center

hole,

the

drill

in

the

other.

With

the

spindle

turning

at

about

600 R.P.M.

the

tailstock

ram

is

then

advanced

moving

the

work

into

the

drill

as

shown

in

Figure

20.

If

this

method

is not

used

the

center

holes

may

be

drilled

by

placing

the

work

in

a drill

press,

or

the

work

may

be

held

in

a

universal

three-jaw

scroll

chuck

and

the

countersink

drill

held

in

the

tailstock

in a drill

chuck.

When

this

method

is

used

the

end

of

the

shaft

should

be

faced

smooth

before

drilling

the

center

hole

When

drilled

and

countersunk

the

holes

should

be

deep

enough

to

prevent

the

points

of

the

lathe

center

touch-

ing

the

bottom,

and

the

tapered

sides

should

exactly

fit

the

60°

anqle

of

the

centers.

If

they

do

not

the

work

14

TAILSTOCK

FIGURE

21-MOUNTING

BETWEEN

CENTERS

will

not

turn

evenly

or

smooth

and

will

be

inaccurate.

A

correctly

drilled

and

countersunk

hole

is

shown

in

Figure

22.

Lubricate

the

end

centers

by

filling

with

heavy

grease

or

with

white

lead

thinned

with

machine

oil

or

light

cylinder

oil.

Place

the

end

of

the

work

in

a

lathe

dog

so

that

the

tail

of

the

dog

extends

beyond

the

end

of

the

work

and

into

the

slot of

the

face

plate,

without

interfering

with

the

headstock

.

center.

The

work

should

now

rest

firmly

on

both

centers

but

should

not

bind.

To

test

the

mount-

ing,

place

a

finger

on

the

tail

of

the

dog

and

move

it

back

and

forth

within

the

face

plate

slot. You

should

be

able

to

move

it

easily,

but

not

too

easily.

When

the

pressure

on

the

ends

has

been

adjusted

lock

the

tailpost

ram

by

turning

the

binding

lever

to

the

right.

CHUCKS

Two

types

of

chuck

commonly

used

are

the

3-JAW

UNIVERSAL CHUCK

and

the

4-JAW INDEPENDENT

CHUCK.

These

are

used

in

turning

the

work

that

can

not

be

readily

turned

between

centers.

See

Figure

23.

FIGURE

22-3

AND

4

JAW

CHUCKS

Some

chucks

mount

directly

on

to

the

spindle

nose,

while

others

are

bolted

to

an

adapter

plate

which

fits

on

to

the

spindle.

Before

mounting

a

chuck

or

face

plate

clean

the

spindle

shoulder

and

chuck

back

and

oil

the

threads

of

the

spindle

head

and

chuck

thoroughly.

o

Turn

the

:huck

on

by

hand,

being

careful

not to

spin

it

up

to

the

shoulder

as

it

may

jam.

Never

use

lathe

power

to

screw

a

chuck

on

or

off of

the

spindle.

The

chuck

can

be

loosened

for

removal

by

(1)

Engaging

the

back

gears

while

the

bull

gear

is

connected

to

the

spindle

pulley,

so

that

the

spindle

will not turn,

and

turning

the

chuck

by

placing

the

chuck

wrench

in

its

hole

and

pulling

on

it.

(2)

Placing

a

block

of

wood

be-

tween

the

chuck

jaw

and

the

lathe

bed,

engaging

the

back

gears,

and

turning

the

spindle

by

pulling

by

hand

on

the

belt

.

Take

care

in

removing

the

chuck.

You

may

damage

the

spindle

threads

or

you

may

damage

the

bed

ways

if

the

chuck

falls

on

them.

The 4-jaw

independent

chuck

is

recommended

if

the

lathe

is

to

have

only

one

chuck

as

it will

hold

square,

round

or

irregular

shaped

work

in

either

a

concentric

or

eccentric

position

.

Each

jaw

is

controlled

by

a

head

screw,

a

number

of

concentric

circles

scribed

on

the

face

permitting

the

approximate

centering

of

the

work

by

moving

all

jaws

to

:he

same

line

or

to

the

same

distance

from.

the

same

line.

The

work

is

then

revolved

by

hand

and

a

piece

of

chalk

held

lightly

against

the

work

to

mark

the

high

spots.

The

jaw

opposite

the

high

point

is

loosened

and

that

behind

it

tightened

until

the

work

is

centered.

The 3-jaw

universal

chuck

is

self-

centering,

all

jaws

working

from

one

screw

which

saves

time

and

trouble

in

centering

round

or

hexagonal

work

but

it

can

not

be

used

for

square

or

irregular

shapes.

The

4-jaw

chuck

can

be

adjusted

to

any

degree

of

accuracy

required.

3-jaw

chucks

are

usually

accurate

to

.003

when

new.

If

greater

accuracy

than

this

is

re·

quired,

the

jaws

may

be

shimmed

as

needed.

The

jaws

of

the

4-jaw

chuck

are

reversible,

while

an

additional

set

of

jaws

are

supplied

with

the

3-

jaw

chuck

for

internal

chucking

in

which

case

the

jaws

are

placed

inside

the

work

and

the

outside

turned.

DRILL

CHUCKS (Fig. 23A)

are

used

both

on

the

tailstock

of a

lathe

with

the

work

turning

and

on

the

headstock

of

the

lathe

with

the

work

held

.

Although

for

production

drilling

, a drill

press

is

generally

used,

there

are

many

small

jobs

of drilling,

reaming,

tapping,

etc.,

that

are

conveniently

handled

by

means

of a

lathe

drill

chuck.

15

A

B

FIGURE

23-LATHE

CHUCKS

THE CENTER REST CHUCK (Fig.

23B)

is

mounted

in

the

tailstock

by

means

of a

solid

tapered

arbor

which

replaces

the

center.

The

stationary

bronze

jaws

provide

an

accurate

support

for

turning

round

work

where

a

center

cannot

be

used.

E

,

[)

"~~

r

B

lJ

B

.

~

-

_.'"

'"~

·

::..

·

.i

'

-.i

·

::.

·

:.o;:.c.

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c

LATHE

HEADSTOCK

SPINDLE

FIGURE

24

-DRAW-IN

COLLET

ATTACHMENT

DRAW-IN COLLET CHUCK.

Small

work

that

must

be

very

accurate

is

mounted

in

a

draw-in

collet

placed

within

the

headstock

spindle.

The

assembly

consists

of a

draw-in

spindle

(A

in

Fig.

25)

threaded

at

the

right

end

to

receive

the

collet; a

tapered

closing

sleeve

(B);

a

split

holding

collet

(C);

spindle

nose

cap

(D);

and

spindle

nose

cap

wrench

(E).

The

tapered

closing

sleeve

fits into

the

headstock

spindle

and

adapts

it to

the

collet.

The

work

is

placed

in

the

split

end

of

the

collet

and

the

collet

closed

by

pressure

as

it

is

drawn

into

the

taper

by

the

draw-in

spindle

which

enters

the

headstock

spindle

from

the

other

end.

Never

use

a

collet

for

work

more

than

.005

inch

larger

or

smaller

than

its

rated

diameter.

Before

mounting

·

work

in

a collet,

all

parts-work,

collet,

spindle,

and

taper-

must

be

wiped

clean

and

dry.

When

removing

the

collet

assembly

unscrew

the

draw-in

spindle

a

couple

of

turns

and

press

the

collet

loose. To

remove

the

tapered

closing

sleeve,

unscrew

the

spindle

nose

cap

with

spanner

wrench

which

forces

the

sleeve

out

of

the

lathe

spindle

.

FIGURE

27-FACE

PLATE

FACE

PLATE

MOUNTING

Many

irregular

shapes

are

best

mounted

for

turning

by

clamping

to

the

face

plate

directly

or

by

fastening

to

an

angle

plate

which

in

turn

is

mounted

on

the

face

plate.

(Fig.

27)

Be

careful

in

bolting

down

not to

spring

the

work

on

the

plate

and

use

the

same

care

in

screwing

the

face

plate

on

the

lathe

spindle

as

described

for

mounting

chucks.

Heavy

work

mounted

off

center

should

be

counterbalanced

by

attaching

balancing

weights

to

the

opposite

edge

of

the

face

plate

. To

locate

the

work

accurately

on

the

face

plate

use

either

a

dial

indicator

or

a

center

indicator.

FIGURE

28-MANDREL

outer

surface

to

be

turned

instead

of

the

limited

surfac+

that

would

be

available

if

the

piece

were

held

in

a

chuck.

Although

mandrels

are

available

which

may

be

ex-

panded

to fit

the

.-

..

ole

by

forcing

out

grips

on

the

sides,

a

mandrel

is

usually

a

piece

of

steel

with

a

slight

taper

(.006

inches

per

foot)

the

ends

flattened

for

the

lathe

dog

and

the

piece

held

to

the

mandrel

by

friction.

When

mounting

the

work

it

is

advisable

to oil

both

the

mandrel

and

the

hole

to

prevent

the

work

"freezing"

on

the

mandrel.

In

driving

the

mandrel

out

of

the

work

do

not

use

a

steel

hammer

without

protecting

the

end

of

the

MANDREL

MOUNTING

mandrel

from

damage.

Make

sure

that

mandrel

is

Hollow

pieces

may

be

mounted

on

a

mandrel

and

the

driven

off

in

the

opposite

direction

than

that

from

which

mandrel

mounted

between

centers,

allowing

the

entire

it

entered

the

work.

Te1

minol

Box

i,.l

T2

f

yc2

Cl

!rJ

T4!

I I

Ll

L2

Terminal

lox

F4

yTSny

T7

Tfa

Til

Tl T 2

Tl

Ll3

LZ

Ll

. T7, T

II

T9

Tl T 2

T3

L2

Ll

3-I -

52-2M

Sw

itch

Boll

yr1-2

Leo

Cl

czy

!n-4

I

Switch

lox

iT

1·7

L.l<>

o-Ll

T2·11!

tr,.~

L2y

Switch

lox

Fig.

29

Motor

and

Switch Wiring Diagram

No. 1105 Motor

(Capacitor

type)

lf2

H.P. 115 volt,

60

cycle,

single

phase

No. 0639

Switch

(R-1144)

.

..

No.

1110

Motor

Vz

H.P.

220

volt,

60

cycle,

three

phase

No. 0636

Switch

(R-1143)

No.

1111

Mote::

% H.P. 220 volt,

60

cycle,

three

phase

No. 0636 Switch

(R-1143)

16

No. 1105 Motor

(Capacitor

type)

lf:z

H.P. 230 volt; .

60

cycle,

single

phase

No. 0639

Switch

(R-1144)

No.

1110

Motor

lf:z

H.P.

440

volt,

60

cycle,

three

phase

No. 0636

Switch

(R-1143)

No. 1115 Motor

(Capacitor

type)

3

/4

H.P.

115

volt,

60

cycle,

single

phase

No. 0639

Switch

<R-1144)

Terminal

lo•

Switch

...

T3

T4r

0

L.l<>

TZ

Tl

T41

C2

Cl Cl

L.~

I I

L.Z

Ll

Te,minol

lox

..........

rT

"J

r-

f-oTI

Llo

~

TJ

T7

Til

lTI

Tlz

T~

T3

L2y

J

3

11

Ll

T..-mtnol

lo•

Switch

...

~,..

Cll

A,.,

1..2"'

cz

Cll

lr.

cr.

T'f

1..1

y

I I

1..1

1..&

PR

LITHO

IN

U.S.A.

Logan 915 Instruction sheet

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