Test 2 Flashcards
Layout Drawings
A pure geometric representation of an entire assembly prepared in initial design stages to resolve spatial issues and tradeoffs without full attention of dimensioning or presentation
For effective communication, drawings must be…
Clear: easy to understand and interpret (not ambiguous) Complete: no missing info, particularly dimensions Accurate: free of errors
Detail Drawings
Supplies complete detail for making a single part including its shape and size descriptions, material call-out and specifications of tolerance and surface finish
Assembly Drawings
Depicts assemblies of fully detailed component parts, arranged as they appear in the final assembly
Title Block
Contains identifying information such as a part number, it’s revision and title or description, the name of the company, scale if any, and default values for tolerance and surface finish
Lines which define basic geometry form are…
Visible lines Hidden lines Center lines
Lines associated with dimensions are…
Extension lines Dimension lines
Pointing and advisory lines include
Leader lines Break lines Cutting plane and Section lines
Projections
Graphical representatives used to describe 3D objects onto 2D paper
Types of Projections
Pictorial: isometric, oblique, and perspective useful for general illustrations Orthographic: used exclusively for technical drawings
Orthographic Projections
In ortho projections images of an object are projected on planes as they appear to the eye when viewed from 3 orthogonal directions FRONT TOP SIDE
Orthographic Projection: 1st Angle
Used in Europe and some Pacific rim countries The object is between the observer and protection plane
Orthographic Projection: 3rd Angle
Used in the US, Canada, and Japan The protection plane is between the observer and object
Sectional Views
Sections show interior details that are too complex to represent with hidden lines
Concentric Cylindrical Features
Best shown in a longitudinal (side) view
One-view Drawings
Use symbol ø (metric) outer the abbreviation DIA (inches)
Circular Arc
Dimensions via its radius
Cylindrical Holes
Dimension with a leader pointing to the hole and the diameter is preceded by ø or followed with DIA
Circular Tapers
Use a suitable combination
Flat Tapers
Dimensioned in a fashion similar to circular tapers
Chamfers
Dimensioned via length and angle
Undercuts
Dimensioned with a note specifying width followed by diameter
Dimensioning System
The choice of dimensioning systems depends on whether the drawing is intended for BATCH (general purpose tools and gages) or MASS PRODUCTION (specialized tools/gages)
Coordinate Dimensioning System
Defines distance, location, and size by means of linear dimension measured from reference axes or datum plane
True Position Dimension
Features defined in terms of their most likely or mean position
Polar Coordinate System
Defines position by means of a radius and an angle
Chain and Datum Dimension
Dimensioning of feature sequentially in a chain-like manner or from a common reference (datum) point or line
Negatives to Coordinate Dimensioning
- Only implies and does not precisely define how dimensions are to be measured for checking
- When no datum is specified, coordinate dimensions apple on point-to-point basis (Fig. 40)
- When datum feature is given (Fig. 41) measurement is made from the theoretical datum, not from the actual feature itself
- Coordinate Dimensioning does not specify straightness, meaning the part could be within the thickness size tolerance but could be significantly bowed and unacceptable
GD&T must be…
- Complete
- Functional
- Max Tolerances
- Clear
Datum Reference Frame
Datum references made in a feature control frame determine where a part is located in the datum reference frame
Feature Control Frame
a rectanle which is divided into compartments within which the geometric characteristic symbo, tolerences, value, modifiers, and datum regerences are placed.
Maximum Material Condition
refers to the feature-of-size that contains the greatest amount of material, yet remains within its tolerence zone
- Has the largest pin diameter
- has the smallest hole size
Least Material Condition
refers to a feature of size containing the least amount of materials, yet remains within its tolerance zone
- Has smallest pin diameter
- Has largest hole size
Manufacturing Process
Also known as process planning, is the process a product goes through starting with its raw materials and ending with the final product.
Production Process
Production Prosses are used to make any manufactured item.
- Source the parts needed
- Make the product
- Deliver the product
Lead Time
the time needed to respond to a customer order
Customer Order Developing Point
Where inventory is positioned to allow entities in the supply chain to operate independently.
Lean Manufacturing
- a means of achieving high levels of customer service with minimal inventory investment.
- use lean manufacturing to achieve a higher service level for a given inventory investment.
Make-to-Stock
- serve customer from finished goods inventory
- Ex: tv’s, clothing, packaged food products
- Issues: balance the level of inventory vs. the demand
Assemble-to-Order
- Combine the number of preassembled parts to meet customer specifications.
- Ex: Dell Computers makes their desktop computers with different components and styles.
- Need a design that enables flexibility for combing components.
Make-to-Order
make customer product from raw materials, parts, and components
Engineer-to-Order
designing with customer to make the product
Project
- the product remains in a fixed location (manufacturing equipment is moved to the product)
- remains in a fixed location
- high degree of task ordering
- project layout maybe developed by arranging materials according to their assembly
Workcenter (Job Shop)
- similar equipment or functions are grouped together
- desing workcenters that optimizes the movement of material
- optimal placement often means placing workcenters with larger interdepartmental traggic adjacent to eachother
- sometimes is referred to as a departement and is focused on a particular type of operation
Manufacturing Cell
- a dedicated area where products that are similar in processing requirements are produced.
- formed by allocating dissimilar machines to cells that are designed to work on similar products.
Assembly Line
- work processes are arranged according to the progressive steps by which the product is made.
- designed for the special purpose of building a product by going through a series of progressive steps
- AVOID BOTTLENECKING: having one step wait for another step
Continuous Process
- Assembly line only the glow is continuous such as with liquids.
- designed for the special purpose of building a product by going through a series of progressive steps
- AVOID BOTTLENECKING: having one step wait for another step
Product Process Matrix
REFER TO NOTES OR BOOK 10/15/14
Make-or-Buy Decision
- What components need to be made?
- MAKE it yourseld
- OR
- BUY it from someone who is already making it
- MAKE it yourseld
Specific Process Selection
- Which process are you going to select in order to create a product
- most of the time the most efficient way is picked
Specific Equipment Selection
- Picking the equipment that will be used to create a product
Process Plans (or documentation)
- tells how the product will be made
Process Analysis
- Measures its efficiency
Break-Even Analysis
- model seeks to determine the point in units produced where a company will start making profit on the process
- defined as standard approach to choosing among alternative proceses or equipment.
- A point where Total Revenue (TR) = Total Cost (TC)
- Equation:
BEP = FC / (R-v);
R=Revenue Price, v=variable price or cost/unit
Manufacturing Process Flow Design
- a method to evaluate the sepcific processes that material follow as they move through the plant
- focus should be on the identification of activities that can be minimized or eliminated.
- movement & storage
- the fewer the moves, delays, and storage, the better the flow.
Assembly Drawing
an exploded view of the product showing its component parts
Assembly Chart
defines how parts go together, their order of assembly, and overall flow pattern
Operation and Route Sheet
specifies operations and process routing
Process Flowchart (Flow Diagram)
denotes what happens to the product as it progresses throught the production facility.
Total Quality Management (TQM)
- managing the entire organization so that it excels on all dimensions of products and services that are important to the customer.
- Goals:
- Careful design of the product or service
- Ensuring that the organization’s systems’s can consistently produce the design
What is Quality?
Fitness for use
Dimensions of Product Quality:
- Performance
basic operating characteristics
Dimensions of Product Quality:
- Features
“extra” items added to basic features
Dimensions of Product Quality
- Reliability
probability product will operate in appropriate manner over time under normal operating conditions.
Dimensions of Product Quality:
- Conformance
meeting pre-established standards
Dimensions of Product Quality:
- Durability
life span before replacement
Dimensions of Product Quality:
- Servicability or Maintainability
ease of getting repairs, speed, and competence of repairs
Dimensions of Product Quality:
- Aesthetics
look, feel, sound, smell or taste of product
Dimensions of Product Quality:
- Safety
freedom from injury or harm
Dimensions of Product Quality:
- Reliability
subjective perceptions based on brand name, advertising, etc.
