Machining: Lathes

Question 1

How is a lathe sized?

Answer 1

Determined by the largest diameter that can be supported over the ways and greatest length that can be supported between centres

Question 2

How is the weight of a lathe determined?

Answer 2

Rigidity of the bed/ ability to resist deflection

Question 3

What does the headstock house?

Answer 3

Spindle, bearings and belts

Question 4

What are the components of the carriage?

Answer 4

Saddle, cross-slide, compound rest and apron

Question 5

How far can a compound rest be swivelled?

Answer 5

360 degrees

Question 6

What is a steady rest?

Answer 6

Attaches to the ways
Has 3 adjustable jaws
Used with long thin pieces
supports at the end or in the middle

Question 7

What is a follower rest?

Answer 7

Keeps workpiece from deflecting
Supports in area of the cut
Mounts on the carriage
Has 2 contact points

Question 8

What is a taper attachment?

Answer 8

Allows lathe to cut taper by moving carriage and cross slide at the same time

Question 9

What are the two tapers on a headstock spindle?

Answer 9

D1 to align chuck
Morse taper to hold centre

Question 10

Milling machine taper is?

Answer 10

3.5 inch taper per foot

Question 11

Jacobs taper range is?

Answer 11

0.591-0.979 inch per foot

Question 12

How many tools does a quick change tool post hold?

Answer 12

One

Question 13

Multi position tool post is set in increments of?

Answer 13

15 degrees

Question 14

What requirements do tool holding systems have?

Answer 14

Must be held rigid
Must be adjustable
Be repeatable

Question 15

What are 4 tool holders?

Answer 15

Parting
Forming
Knurling
Boring

Question 16

What are the 2 types of Knurls?

Answer 16

Diamond and straight

Question 17

What are boring bars used for?

Answer 17

Machine inside diameters

Question 18

What centre turns with the headstock spindle?

Answer 18

Live centre

Question 19

What is the included angle on a live centre?

Answer 19

60 degrees

Question 20

What is the most accurate centre?

Answer 20

Solid dead centre

Question 21

What is a lathe dog?

Answer 21

Transmits power from the spindle to workpiece when held between centres

Question 22

What is a drive plate used for?

Answer 22

Flat disc that attaches to spindle, turns a lathe dog

Question 23

How do you size a chuck?

Answer 23

By the outside diameter

Question 24

Two types of chucks

Answer 24

3 jaw
4 jaw

Question 25

What is the difference between a 3 jaw and 4 jaw chuck?

Answer 25

3 jaw- has scroll plate which lines jaws up to run true
4 jaw-jaws are independent, must be dialed in

Question 26

Taper per foot on an arbor

Answer 26

0.006-0.008 inch taper per foot

Question 27

What is the metric cutting speed formula?

Answer 27

RPM=Cutting speed x 320 / diameter

Question 28

What is the imperial cutting speed formula?

Answer 28

RPM= Cutting speed x 4 / diameter

Question 29

What is feed rate measured in?

Answer 29

Mm or inches per revolution

Question 30

What feed rate is used for finishing?

Answer 30

0.002-0.005 inches per revolution

Question 31

What sets the depth of cut?

Answer 31

Cross feed dial

Question 32

How much does a direct reading dial move?

Answer 32

0.001 inch per increment
(On diameter)

Question 33

How much does an indirect reading dial move?

Answer 33

0.002 inch per increment
(Twice the radius)

Question 34

When roughing and setting depth of cut, how much should you leave for finishing?

Answer 34

0.030 inch

Question 35

What is the formula for calculating straight depth of cut?

Answer 35

0.6134 (constant) x pitch

Question 36

How much does knurling increase a diameter?

Answer 36

Up to 0.030’

Question 37

How to calculate Tailstock offset for an imperial taper

Answer 37

Taper per foot x overall length / 24