mechanical design/drafting
TRANSCRIPT
Mechanical Design/Drafting
University of South FloridaF e b r u a r y 2 8 , 2 0 1 9
W W W . M C C S T . C O ML A N D I A I R I S E A
SERVING AMERICA’S
HEROES, AS ONLY
ENGINEERS CAN…
We Deliver MechanicallyRugged Solutions forAerospace, Defense,and Homeland Security
McCormick Stevenson (MCCST) is a mechanicalengineering and
product development firm primarily serving Prime Contractors in
the Aerospace and Defense industry
W H O I S M c C O R M I C K S T E V E N S O N ?
FOUNDED IN1999
OFFICES IN
CLEARWATER, FL
40EMPLOYEES
WOMAN-OWNED
SMALLBUSINESS
SECRET PERSONNEL
ANDFACILITY
CLEARANCES
2
Nat McCormickDesign Manager
3
ArmamentSystems
(Weapons & Ancillaries)
• Missiles
• Munitions
• Launchers
• Guns
• Related Components
Defense Electronic Systems
(C4ISR)
• Communications
• Computers
• Surveillance
• Reconnaissance
• Avionics
• Guidance & Navigation
W H O I S M c C O R M I C K S T E V E N S O N ?
M I N I M I Z E
SIZE WEIGHT COST
S U R V I V E
SHOCK VIBRATION TEMPERATURE
M A N A G E
R ISK HEAT
H o w d o e s t h e d e s i g n p r o c e s s w o r k ?
4
CONOPS,
System
Timeline,
Use Cases
Hardware / Software Realization
Stakeholder
Requirements
& Concept of
Operations
System Architecture
& Requirements
System
Validation
System
Verification
SRR
SFR
PDR
CDR
DRR
TRR
SVR
PCA PRR
F
A
P
Unit/Device
Verification
IDRIDR
System
Level M&S
and Trade
Studies
Subsystem
Level M&S
and Trade
Studies
Detailed
Design M&S
and Trade
Studies
Mission
Model
Verification
System
Model
Validation,
Design
Margin
Subsystem
Model
Validation,
Design
Margin
Detailed
Model
Validation,
Design
Margin
Initial Modeling & Simulation (M&S)
Based on available data
(May be unvalidated models)
Final Modeling & Simulation (M&S)
(High Fidelity Validated Models))
Text TextSystem Validation Loop
(Measures of Effectiveness)
Text TextSystem Verification Loop
(Measures of Performance)
Text Text
Text Text
(Component
Definition)
Subsystem Verification Loop
(Allocated Functions & Performance)Text Text
Unit / Device
Verification
Subsystem
Verification
Detailed
Design
High Level
Design
FCA
Requirements Development
Requirements Verification
Requirements Management
KEY REVIEWS & AUDITS
CDR – Critical Design Review
DRR – Design Readiness Review
FCA - Functional Configuration Audit
IDR – Interim Design Review
PCA - Physical Configuration Audit
PDR – Preliminary Design Review
PRR – Production Readiness Review
SFR – System Functional Review
SRR – System Requirements Review
SVR – System Verification Review
VRR – Verification Readiness Review
CONFIGURATION BASELINES
F Functional Baseline
A Allocated Baseline
P Product Baseline
F
A
P
D e s i g n R e f e r e n c e s
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Helpful Design Referenceso Mil-Spec Reference
o https://quicksearch.dla.mil/qsSearch.aspx
o Wrench clearance Calculator
o http://icrank.com/cgi-bin/pageman/pageout.cgi?path=/data/wrench/wrench.html&t=2
o Material Stock
o https://www.alro.com/datacatalog/metalsguidecatalog.aspx
o Hardware purchase
o https://www.mcmaster.com/
o Clearance holes, fits, threads and much more in Machinery’s Handbook (GO BUY THIS)
D e s i g n R e f e r e n c e s
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Default tolerance block
Zone Identification
Design Activity
Finish/Material
Projection Style
Used On/Next Assy
NOTES (UNLESS OTHERWISE SPECIFIED)
REVISION BLOCK
Proprietary and/or distribution statements
CAGE Code(Commercial And Government Entity)
Description
D r a f t i n g B a s i c s
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Drafting matters…o Drawings are used as a requirements communication tool
o Materials
o Finishes
o Tolerances
o Threads
o Part marking & Identification
o Design intent
o Golden Rule: ABC (ALWAYS BE CLEAR)
o Clear drawings are critical to project success
o Other people need to be able to read the drawing
and reach the same conclusion.
o This is an expensive process
o Drawings take time to create, check, release
o Manufacturer’s then must live with them
o Take pride in your work
Critical Specifications
o ASME Y14.100 -2017 : Engineering Drawing
Practices
o ASME Y14.5-2009 now 2018 : Dimensioning
and Tolerancing (GO BUY THIS)
o ASME 14.24-2012 : Types and Applications of
Engineering Drawings
o And many more…
D r a f t i n g B a s i c s
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There Different types of dimensioning approaches
o Baseline
o Ordinate
o Rectangular (Linear)
o Polar
o Tabulated
Think about which method is applicable for your application
Be Specific & Thoughtful
References: ASME Y14.5-2009
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D r a f t i n g B a s i c s
Be Clearo Call out tolerance zones where helpful
o Add notes as needed
o Indicate holes in pattern
o Make sections
o Add Detail views
o Sheets are cheap with CAD tools!
o Add applicable reference information
Be Neat & Consistento Don’t clutter views with dimensions
o Check text sizes meet specifications
o Group dimensions for like features
o Hole patterns
o External features
o Basic dimensions
o Make sure components that mate
have consistent orientations and that
the dimensioning approaches on their
drawing.
Be Thorough & Preciseo Tolerances on all dimensions
o Think about the tolerances applied.
Remember: This is a requirements
document
o Check your own work before asking for
peer review
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D r a f t i n g B a s i c s
References: ASME Y14.5-2009
H o w d o e s t h e d e s i g n p r o c e s s w o r k ?
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References: ASME Y14.5-2009
H o w d o e s t h e d e s i g n p r o c e s s w o r k ?
12
References: ASME Y14.5-2009
H o w d o e s t h e d e s i g n p r o c e s s w o r k ?
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References: ASME Y14.5-2009
G e o m e t r i c D i m e n s i o n i n g & To l e r a n c i n g
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Backgroundo Controlled by ASME Y14.5
o Communicates design intent
o Easier that rectangular tolerancing
o Helps with inspection
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Processo Consider how part will be inspected
o Establish datum setup based on design
intent
o Think of form and orientation
tolerances as needed
o Apply location tolerances to features
Definitionso Form tolerances: How much a feature
can vary relative to it’s perfect
counterpart. HAVE NO DATUM
REFERENCES (Flatness, Straightness,
Circularity, Cylindricity)
o Orientation tolerances: Control the
orientation of a feature or group of
features relative to specified datums.
(Perpendicularity, Parallelism,
Angularity)
o Location tolerances: Control the
location of a feature or group of
features relative to specified datums.
(Position, Concentricity, Symmetry)
o Runout tolerances: Controls functional
relationship of features to datum axis.
o Profile Tolerances: Can control size,
form, orientation, and location.
25400 US HIGHWAY 19 NORTH, SUITE 162 CLEARWATER, FL 33763 PH: (727) 735-9633 FAX: (727) 736-8553 WWW.MCCST.COM
Serving America’s Heroes, as Only Engineers Can…
W W W . M C C S T . C O ML A N D I A I R I S E A