Post on 05-Jan-2016
transcript
Chapter 11: Threads and Fasteners
Agenda
Why they are important
Creating Threads and blocks to re-use them
Creating Hexagonal Bolt and Nut shapes
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But First…TEST 2 !!! Next Saturday 1-2PM
Will Cover: Chapters 6 -10Sectional Views
Auxiliary Views
Dimensioning
Tolerancing
Geometric Tolerancing
Open Book and NotesYou may be asked to do a hand sketch
• Practice Visualizing aux views…see examples
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Sample Auxiliary View Problems
Threads and Fasteners
Most mechanical objects need to be held together
DesignCenter choices are somewhat limited
More flexibility and better clarity by making our own and saving for later use
We’ll use them next week:working drawings
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Design Center Demo
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Pre-constructed blocks
Choose Fasteners, US or
Metric
Place, resize, etc
3 ways to represent threads
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Threads—terms and specs
Pitch in threads/mm
or threads/inch
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Preferred Metric Threads
Thread specs for English Units (Inches)
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Detail Thread (Inches)
Creating wblocks
After drawing the object you want to re-useSelect the object
Type “wblock”
Choose a filename reflecting it’s content:• DETLIN-1in
And a place to store it (myDocs, Desktop, USB)
Then you can choose Insert>Block, find the file, and insert (rotating or scaling first as needed)
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MM thread
Or try scaling the inch thread by 20 and saving as a new wblock
DETLMM
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Internal Thread explode then erase, Hatch ANSI 31
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Schematic Thread
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Metric Thread, scale inch by 20
Save as
SCHMMM
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InternalSchematicThread
Scale by 36/20=1.8
Section using Hash ANSI31
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Simplified thread
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Draw hatch before hidden lines
Ortho & SecViews
Internal Threads
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Bolts, Nuts, Screws, Studs
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Nuts and Bolts
Hex Head Bolts HEXHEAD-10mm.dwgDistance across flats should be 1.5D
D=major diameter of the thread
Head thickness should be 0.67D
Finishing Nuts FNUTHEX-10mm.dwgThickness = .88D
Locking Nuts LNUTHEX-10mm.dwgThickness = 0.5D
Insert and scale to Major Diameter of thread
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Sample Problem 11-1: Threaded hole depth
Pilot hole depth
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SP11-2: Length of bolt
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