to apply by 8suNtp31

VIEWS: 10 PAGES: 15

									              Advanced
            Manufacturing
               Choices
                    MAE 165-265
            Spring 2012, Dr. Marc Madou
                      Class 1


7/17/2012
               Advanced Manufacturing Choices
• Manufacturing processes can be organized by considering the
  type of energy required to shape the work-piece. In this
  course, sources of energy considered for manufacturing are:
   – Mechanical energy such as in cutting and shaping
   – Electrical energy
   – Heat energy such as in laser cutting,
   – Chemical energy such as in electro chemical machining.
• Categorizing is often not that simple (e.g., chemical and
  thermal). It is easier to categorize in the case of subtractive
  than in the case of additive manufacturing.


7/17/2012
            Advanced Manufacturing Choices
• Students, guided by product specifications and a
  design will be able to decide:
  – 1) When to apply mechanical machining vs. lithography
    based machining,
  – 2) What type of mechanical machining and what type of
    lithography based machining to apply,
  – 3) When to employ bottom-up vs. top-down manufacturing,
  – 4) When to choose serial, batch or continuous
    manufacturing and
  – 5) What rapid prototyping method to select.
• A logical decision tree will be presented to sort out
   the machining options.
• Examples will include a variety of products ranging in
7/17/2012
   size from nanometers to centimeters.
                          Advanced
              Manufacturing Choices

 • The size of things




7/17/2012
               Advanced Manufacturing Choices
• Syllabus: Topics
    1. Serial, batch and continuous manufacturing processes.
    2. Relative tolerances vs. absolute machining tolerances.
    3. Principles of manufacturing processes I. Mechanical
       energy: e.g., Cutting, Shaping, Forging, Ultrasonic
       Machining, Sputtering.
    4. Principles of manufacturing processes II. Electrical
       energy: e.g., Electron Discharge Machining (EDM)
    5. Principles of manufacturing processes III. Heat energy:
       e.g. , Laser machining, plastic molding.



7/17/2012
            Advanced Manufacturing Choices
6. Principles of manufacturing processes IV. Chemical
    energy: Electrochemical Machining (ECM), Chemical
    Machining
7. Next generation lithography tools,
8. Nanomachining tools.
9. Top-down vs. bottom-up machining.
10. Rapid prototyping, layered manufacturing.
11. Matching manufacturing processes to product
    specification and design.
12. Manufacturing process decision tree.

7/17/2012
                                      Class 1
 • Definition of manufacturing
 • Serial, batch and continuous
   manufacturing processes.
 • Relative tolerances vs. absolute
   machining tolerances.




7/17/2012
                             Definition of
                            Manufacturing
• Manufacturing is the use of machines, tools and
  labor to make things for use or sale. The term may
  refer to a range of human activity, from handicraft
  to high tech, but is most commonly applied to
  industrial production, in which raw materials are
  transformed into finished goods on a large scale.
  Such finished goods may be used for manufacturing
  other, more complex products, such as household
  appliances or automobiles, or sold to wholesalers,
  who in turn sell them to retailers, who then sell
  them to end users - the "consumers". Wikipedia
7/17/2012
                 Serial, batch and continuous
                    manufacturing processes.
• Single unit production or serial production
• The primary characteristic of batch
  production is that a group of identical
  components are completed at a workstation
  before they move to the next one (e.g., IC
  fabrication).
• Continuous production is a method used to
  manufacture, produce, or process materials
  without interruption

7/17/2012
            Serial, batch and continuous
               manufacturing processes.




7/17/2012
            Serial, batch and continuous
               manufacturing processes.




7/17/2012
             Relative tolerances vs. absolute
                       machining tolerances.
• A dimension is a numerical value
  expressed in appropriate units of
  measure and used to define size,               Dimension with
  location, orientation, form or other           Limit Tolerance

  geometric characteristics of a part.
• A tolerance is the acceptable
  variation of feature from the
  specified dimension
• Relative tolerance: tolerance on
  dimension over dimension
7/17/2012                                   Dimension with
                                         Plus-Minus Tolerance
            Relative tolerances vs. absolute
                      machining tolerances.




7/17/2012
                Relative tolerances vs. absolute
                          machining tolerances.
• Lithography (e.g. Si-                    Precision Machining Application Domain



  micromachining) is
                                               10 km
                                City
                                                                                   Re lat iv e Tole rance
                                               1 km




  excellent for small
                                                                               100 %10 % 1% 0.1 % 0.01 % 0.01 % 0.0001 %
                                               100 m
                                                                           100 m
                                House
                                               10 m                                                         Pre cision M achining



  absolute tolerances           Arm
                                               1 m


                                               10 cm
                                                       Absolute size
                                                                            1 m




• For relative tolerances,                     1 cm                        1 cm




  ultra-fine diamond milling
                                Optic          1 mm
                                al
                                fiber          100 µm                    100 µm




  is better
                                                                  Absolute tolerance
                                               10 µm


                                Bacteria       1 µm                        1 µm




• In some cases we might
                                                                                           Re lat iv e tole rance s for building
                                               0.1 µm
                                                                                           a house and a lit hography base d
                                Virus                                                      micr omachine
                                               0.01 µm                   0.01 µm



  want to keep our              Atom
                                               1 nm

                                                                                  Line ar dime nsion


  micromachine somewhat
                                               1 Å




  larger to optimize relative
                                            Line ar dime nsion




  tolerances
7/17/2012
                Relative tolerances vs. absolute
                          machining tolerances.
      • “The total amount by
        which a given
        dimension may vary, or
        the difference between
        the limits” - ANSI
        Y14.5M-1982(R1988)
        Standard [R1.4]
      • Nominal tolerances for
        steel (see figure)
      • Tighter tolerances =>
        increase cost $

7/17/2012

								
To top