1. Horizontal Milling Machines and Accessories
Session 12

2. Horizontal Milling Machines
Manufacturing-type
Cutter height is controlled by vertical movement of headstock
Special-type
Designed for specific milling operations
Knee-and-column-type
Relationship between cutter height and work controlled by vertical movement of table

3. Manufacturing-Type
Used primarily for quantity production of identical parts
Distinctive features
Automatic cycle of cutter and work approach
Rapid movement during non-cutting cycle
Automatic spindle stop

4. Manufacturing-Type Two common types Plain manufacturing type
Small plain automatic knee and column type

5. Plain Manufacturing Type Milling Machine

6. Special-Type Machines
Designed for individual milling operations
Used for only one particular type of job
Completely automatic
Employed when hundreds or thousands of similar pieces are to be machined

7. Machining Centers
Capable of handling wide variety of work all in one setup
Straight and contour milling, drilling, reaming, tapping, and boring
Capable of high production rates while still maintaining high degree of accuracy
Rugged construction, reliable controls
Anti-backlash ball screws

8. Machining Centers

9. Knee-and-Column-Type Milling Machines
Machines in this class fall into three categories:
Plain horizontal milling machine
Universal horizontal milling machines
Vertical milling machines

10. Universal Horizontal Milling Machines
Difference from plain horizontal machine is addition of table swivel housing
Located between table and saddle
Permits table to be swiveled 45º in either direction in a horizontal plane
Used for milling of helical grooves in twist drills, milling cutters, and gears

11. Universal Horizontal Milling Machine

12. Milling Machine Parts Base Column face Knee
Gives support and rigidity to machine
Acts as reservoir for cutting fluids
Column face
Precision-machined and scraped section used to support and guide knee when moved vertically
Knee
Houses feed mechanism
Attached to column face and moved vertically

13. Milling Machine Parts Saddle On top of knee Moved in or out by
means of crossfeed
handwheel (manually
or automatically)
Swivel table housing
Fastened to saddle on
universal milling
machine
Enables table to be swiveled 45º either side of centerline

14. Milling Machine Parts Table
Rests on guideways in saddle and travels left and right
Supports vise and work
Crossfeed handwheel
Used to move table in and out
Table handwheel
Used to move table left and right

15. Milling Machine Parts Feed dial Used to regulate table feeds Spindle
Provides drive for attachments, arbors, cutters
Overarm
Provides for correct alignment and support of arbor and various attachments
Can be adjusted and locked in various positions

16. Milling Machine Parts Arbor support
Fitted to overarm and can be clamped
Aligns and supports various attachments
Elevating screw
Gives upward or downward movement to knee and table (manually or automatically)
Spindle speed dial
Set by crank used to regulate spindle speed

17. Backlash Eliminator
Eliminates backlash (play) between nut and table lead screw
Permits operation of climb (down) milling
Two independent nuts mounted on lead screw
Nuts engage common crown gear which meshes with rack
Axial movement of rack controlled by backlash eliminator engaging knob on front of saddle
Turning knob in, nuts forced to move along lead screw in opposite directions

18. Machine Backlash Eliminator

19. Milling Machine Accessories
Wide variety of accessories greatly increase versatility and productivity
Accessories classed as fixtures or attachments
Work-holding device fastened to table
Designed to hold workpieces that cannot be readily held in vise or when large quantities are to be machined

20. Milling Machine Attachments
Designed to hold special attachment that increase versatility of machine
Vertical, high-speed, universal, rack milling, slotting
Designed to hold standard cutters
Arbors, collets, and adapters
Designed to hold workpiece
Vise, rotary table, indexing (dividing) head

21. Vertical Milling Attachment
Enables plain or universal milling machine to be used as a vertical milling machine
Mounted on face of column or overarm
Angular surfaces made by swiveling head, parallel to face of column up to 45º either side of vertical
Used for face milling, end milling, drilling, boring and T-slot milling
Universal milling attachment modification allows swiveling in two planes for cutting compound angles

22. Rack Milling Attachment
Used to mill longer gear racks (flat gears) than could be cut with standard horizontal milling machine
Rack indexing attachment included

23. Slotting Attachment
Converts rotary motion of spindle into reciprocating motion
Cutting keyways, splines, templates, and irregularly shaped surfaces
Length of stroke controlled by adjustable crank
Tool slide may be swiveled to any angle in plane parallel to face of column

24. Arbors Arbors Shell-end mill arbors Used for mounting milling cutter
Inserted and held in main spindle by draw bolt
Shell-end mill arbors
Permit face milling horizontally or vertically
Fit into main spindle

25. Collets and Adapters Collet adapters Quick-change adapter
used for mounting drills or other tapered-shank tools in main spindle of machine or vertical milling attachment
Quick-change adapter
Mounted in spindle
Permits such operations as drilling, boring, and milling without change in setup of workpiece

26. Arbors, Collets, and Adapters

27. Milling Machine Vises Plain vise
Jaws parallel or 90º to axis of spindle

28. Milling Machine Vises Swivel base vise
Can swivel through 360º in horizontal plane

29. Milling Machine Vises Universal vise
Can swivel through 360º in horizontal plane and tilted from 0º to 90 in vertical plane

30. Fixturing Systems
Easy-to-adjust Stop

31. Indexing or Dividing Head
Permits cutting of bolt heads, gear teeth, ratchets
Revolve work as required to cut helical gears and flutes in drills, reamers, and other tools
When connected to lead screw of milling machine

32. Horizontal Boring Mill

33. Horizontal Boring Mill