Machining Operations and Machine Tools Review Questions Flashcards Preview

MFE-201 Manufacturing Systems Processes > Machining Operations and Machine Tools Review Questions > Flashcards

Flashcards in Machining Operations and Machine Tools Review Questions Deck (27)
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1

What are the differences between rotational parts and prismatic parts in machining?

Rotational Parts

Cylindrical / disk shaped and are machined on a turning machine

 

Prismatic Parts

Blocked shaped or flat and are generally produced on a milling machine, shaper, or planer

2

Distinguish between generating and forming when machining workpart geometries.

Generating

Geometry of the workpart is determined by the feed trajectory of the cutting tool. The path followed by the tool during its feed motion is imparted to the work surface in order to create the shape

 

Forming

Shape of the part is created by the geometry of the cutting tool.  The cutting edge of the tool has the reverse of the shape to be produced on the part surface

3

Give two examples of machining operations in which generating and forming are combined to create workpart geometry

  • thread cutting on a lathe
  • slotting on a milling machine

4

Describe the turning process

Machine process in whic a single-point tool removes material from the surface of a rotating workpiece.  Toll fed linearly in a direction parallel to the axis of rotation to generate a cylindrical geometru

5

What is the difference between threading and tapping?

Threading performed on a turning machine and produces external threads

 

Tapping performd on a drilling machine and prdocues internal threads

6

How does a boring operation differ from a turning operation?

Boring produces internal cylindrical shape from an existing hole

 

turning produces an external cylindrical shape

7

What is meant by the designation 12 x 36 inch lathe?

Has a 12 inch swing (maximum work diameter that can be accomodated) and a 36 inch distance between centers (maximum work length that can be held between carriers)

8

R16.8Name the various ways in which a workpart can be held in a lathe

  • Between centers
  • Chuck
  • Collet
  • Face plate

9

What is the difference between a live center and a dead center, when these terms are used in the context of workholding in a lathe?

Center

Holds the workpiece at the tailstock end of the live

 

Live Center

Mounted in bearings and rotates with the work

 

Dead Center

Does no rotate, the work rotates about it

10

What is a blind hole?

Blind Hole

Does not exit the work

 

Through Hole

Hole exits both sides of the work

11

wHAT IS THE DISTINGUISHING FEATURE OF A RADIAL DRILL PRESS?

Large drill press designed to cut holes in large parts.  Has a radial arm along which the drilling head can be moved and clamped.

12

What is the difference between peripheral milling and face milling

Peripheral Milling

Axis of the tool is parallel to the surface being machined, and operation is performed by cutting edges on the outside periphery of the cutter

 

Face Milling

Axis of the cutter is perpendicular to the surface being milled, and machining is performed by cutting edges on both ends and outside periphery of the cutter

13

Describe profile milling

Generally invovles the milling pf the outside periphery of a flat part

14

What is pocket milling

Uses an end milling cutter to machine a shallow cavity (pocket) into a flat workpart

15

Describe the difference between up milling and down milling?

Upmilling

Cutter speed direction is opposite of the feed direction

 

Downmilling

direction of cutter rotation is the same as the feed direction

16

How does a universal milling machine differ from a conventional knee-and-column machine

Knee and column milling machine

basic machine tool for milling. Holds a single cutting tool. Main components are a column that supports the spindle and a knee that supports the worktable

 

Universal Milling Machine

Has a worktable that rotates about the vertical axis to present a part at a certain angle

17

What is a machining center

A highly automated machine tool capable of performing multiple machining operations under a computer numerical control in one setup with minimal human attention

18

What can a mill-turn center do that a conventional turning center cannot do?

CNC mill-turn center

Has general configuration of a turning center; can position cylindrical workpart at a specified angle so that a rotating cutting tool can machine features into the outside surface of the part

19

How do shaping and planing differ

Shaping

Speed motion is accomplished by moving the cutting tool

 

Planing

Speed motion is accomplished ny moving the workpart

20

What is the difference between internal broaching and external broaching

External Broaching

performed on outside surface of the work to create a certain cross-sectional shape on the surface

 

Internal Broaching

Accomplished on internal surface of the hole in the part

21

What is the difference between a machining center and a turning center

Machining Centers

Can be applied to every surface of the workpiece

 

Turning Centers

Mainly used for cutting rotated workpieces 

22

How do a turning lathe differ from an engine lathe

Turret Lathe

has a toolholding turret in place of a tailstock; tools in the turret can be brought to work to perform multiple cutting operations on the work without needing to change tools

 

Engine Lathe

Requires manually replacing the tool for a specific machining operation

23

Identify the 3 basic forms of sawing operations

  • hacksawing
  • bandsawing
  • circular sawing

24

Why do costs tend to increase when better surface finish is requried on a machined part

Additional operations such as grinding , lapping, or similar ginishing processes must be included in the manufacturing sequence

25

What are the basic factors that affect surface finish in machining

  • geometric factors
    • type of operation
    • feed
    • tool shape
  • work material factors
    • built up edge effects
    • tearing of the work surface when machining ductile materials
  • Vibration and tool factors
    • setup
    • work part rigidity
      • backlash in the feed mechanism
      •  

26

What are the parameters that have the greatest influence in determining the ideal surface roughness in a turning operation

  • tool nose radius
  • feed

27

Name some of the steps that can be taken to reduce or eliminate vibrations in machining

  • increase stiffness or damping in the setup
  • operate at speeds away from the natural frequency of machine tool system
  • reduce forces in machining by changing feed or depth and cutter design