1. Lathe

2. Parts

3. 1. Headstock
hollow spindle
gear box

4. 2. Tailstock
handwheel
locks

5. 3. Bed (ways) carriage made up of saddle and apron
cross slide
compound rest (rotates to any angle) & holds tool post
half nut lever - used only for cutting threads
thread dial
feed rod - general turning
lead screw (Acme thread) - for threading only

6. 4. Base

7. Lathe spindle - internal Morse taper at nose end
centers
collet assemblies

8. Outside the spindle nose
threaded nose
long taper with drive key
camlock

9. Spring cleaner

10. Spindle Tooling

11. 1. Independent 4 jaw chuck most precise most difficult to set up
holds work more securely
oddly shaped pieces
use dial indicator for centering work piece
can reverse jaws
jaws are removed 3,2,1 and returned in order of 1,2,3

12. 2. Universal 3 jaw chuck some 2 or 6 jaws easier to set up
less precise
jaws will not reverse so a separate set of jaws must be used
chucking
normal
external
internal

13. 3. Drive plate
used with lathe dog to drive work mounted between centers

14. 4. Face plate
can mount work directly to face of plate
has T-slots

15. 5. Collets for small detailed work range only few thousandths of inch
work pieces to be gripped must not vary more than +/- .003”
rough or inaccurate work - don’t use with collet
never tighten a collet without a workpiece in its jaws
rubber flex collets - have a wider range (about .125”)

16. 6. Magnetic chuck

17. Tailstock
jacobs chuck (drills)
taper shank drills
centers

18. Operating the machine controls

19. Hand feeding is not used for long cuts
lack of uniformity
poor surface finish

20. Using power feed and approaching a shoulder, disengage 1/8” before shoulder

21. Micrometer collar graduations
single depth - tool moves as much as the collar shows
you are actually removing twice as much from the diameter
turn in .020” , actually moves in .020” removing .040” from dia.
some lathes built to compensate - turn in .020”, actually moves in .010” to remove .020” from dia.

22. Operations on the lathe

23. 1.) Facing
to obtain flat surface on end of work piece

24. Why is facing done? to establish lengths before center drilling
on parts clamped on face plate

25. Tool must be at centerline of work

26. Lock carriage when facing

27. Can feed in either direction when facing
1. feed from center to outside
better surface finish
difficult to cut on a solid face in the center
2. feed from outside to center (preferred)
can take heavier cuts
easier to cut to scribed lines on the circumference of the work

28. Feed by hand for small diameters

29. Methods of facing to length
face to layout line
less precise
turn compound slide parallel to the ways and use micrometer dial
most precise

30. 2.) Center Drilling also called combination drill and countersink
performed because the hole must have 60 deg angle to clear point of center
range from 1/8” to 3/4” body diameter
don’t feed drill too fast
don’t feed drill too deep

31. 3.) Turning between centers (done after facing and center drilling)

32. Adv:
can turn without eccentricity
can turn more of a shaft

33. Disadv:
no parting
no boring
no drilling

34. Accessories needed tailstock center headstock center drive plate
lathe dog
knockout bar

35. Adjust tailstock so the bent tail of the dog moves freely in its slot

36. Lathe dog tail should not rub on the bottom of the slot

37. 4.) Turning between chuck and a center

38. Adv:
quick setup
positive drive

39. Disadvantage:
eccentricities on a shaft can be caused by chuck jaw inaccuracies
work piece slips endwise into the chuck - come off tailstock center
solutions to this
1. make chalk mark at chuck to monitor slipping
2. machine a shoulder on the shaft to contact face of chuck

40. Cutting tools and tool holders

41. General Single Point Turning Tools
HSS
Carbide
greater rigidity
greater material removal rates

42. Tool geometries (shape of tool)
grooving / parting
threading
knurling
boring - boring bar

43. Tool holders and Tool posts
mounted on compound rest and held in T-slot

44. 1. Standard type (obsolete)
straight shank
left hand
right hand

45. 2. Quick change

46. Tools should be set on the centerline of the work piece for turning (as well as for facing)
can set this by checking with the center in the tailstock
can set this by using a steel rule

47. Checking alignment of lathe centers (4 methods)
points of centers brought together
tailstock witness marks
test bar - uses dial indicator mounted on tool post
cutting and measuring (most accurate)