Machining: Lathes Flashcards
How is a lathe sized?
Determined by the largest diameter that can be supported over the ways and greatest length that can be supported between centres
How is the weight of a lathe determined?
Rigidity of the bed/ ability to resist deflection
What does the headstock house?
Spindle, bearings and belts
What are the components of the carriage?
Saddle, cross-slide, compound rest and apron
How far can a compound rest be swivelled?
360 degrees
What is a steady rest?
Attaches to the ways
Has 3 adjustable jaws
Used with long thin pieces
supports at the end or in the middle
What is a follower rest?
Keeps workpiece from deflecting
Supports in area of the cut
Mounts on the carriage
Has 2 contact points
What is a taper attachment?
Allows lathe to cut taper by moving carriage and cross slide at the same time
What are the two tapers on a headstock spindle?
D1 to align chuck
Morse taper to hold centre
Milling machine taper is?
3.5 inch taper per foot
Jacobs taper range is?
0.591-0.979 inch per foot
How many tools does a quick change tool post hold?
One
Multi position tool post is set in increments of?
15 degrees
What requirements do tool holding systems have?
Must be held rigid
Must be adjustable
Be repeatable
What are 4 tool holders?
Parting
Forming
Knurling
Boring
What are the 2 types of Knurls?
Diamond and straight
What are boring bars used for?
Machine inside diameters
What centre turns with the headstock spindle?
Live centre
What is the included angle on a live centre?
60 degrees
What is the most accurate centre?
Solid dead centre
What is a lathe dog?
Transmits power from the spindle to workpiece when held between centres
What is a drive plate used for?
Flat disc that attaches to spindle, turns a lathe dog
How do you size a chuck?
By the outside diameter
Two types of chucks
3 jaw
4 jaw
What is the difference between a 3 jaw and 4 jaw chuck?
3 jaw- has scroll plate which lines jaws up to run true
4 jaw-jaws are independent, must be dialed in
Taper per foot on an arbor
0.006-0.008 inch taper per foot
What is the metric cutting speed formula?
RPM=Cutting speed x 320 / diameter
What is the imperial cutting speed formula?
RPM= Cutting speed x 4 / diameter
What is feed rate measured in?
Mm or inches per revolution
What feed rate is used for finishing?
0.002-0.005 inches per revolution
What sets the depth of cut?
Cross feed dial
How much does a direct reading dial move?
0.001 inch per increment
(On diameter)
How much does an indirect reading dial move?
0.002 inch per increment
(Twice the radius)
When roughing and setting depth of cut, how much should you leave for finishing?
0.030 inch
What is the formula for calculating straight depth of cut?
0.6134 (constant) x pitch
How much does knurling increase a diameter?
Up to 0.030’
How to calculate Tailstock offset for an imperial taper
Taper per foot x overall length / 24
