1. ADVANCED MECHANICAL DRAFTING
LECTURE #23

2. PROFILE TOLERANCE ZONES
PROFILE OF A LINE
PROFILE OF A SURFACE

3. PROFILE OF A LINE
Forces a surface to have a profile of some desired shape
No datum reference
No diameter symbol
Cannot be modified
Dimensions defining profile shape are basic

4. Applying Profile of a Line
.812
R.005
R.005 +
1.250

1.12
INTERPRETATION
.006 WIDE 2D TOLERANCE ZONE
.81
ALL DIMENSIONS CONTROLLING THE SHAPE OF THE ZONE ARE
BASIC
DRAWING

5. PROFILE OF A SURFACE
Forces a surface to have a profile of some desired shape
May reference a datum
No diameter symbol
Cannot be modified
Dimensions defining profile shape are basic

6. Applying Profile of a Surface
.812
R.005
R.005 +
1.250

1.12
INTERPRETATION
.006 WIDE 3D TOLERANCE ZONE A
.81
ALL DIMENSIONS CONTROLLING THE SHAPE OF THE ZONE ARE
BASIC
DRAWING

7. DATUM TARGETS
Used to define simulated datums on irregular or curved surfaces
Exact locations of points, lines, or areas of contact are specified with basic dimensions
Datum target symbol
Ø.25 A1
Size of contact area (if specifying an area)
Contact point identifier

8. DATUM TARGET POINTS DRAWING INTERPRETATION A1 .25 .50 A .25 .50 A3 A2
DATUM PLANE A
LOCATING PINS
INTERPRETATION

9. DATUM TARGET AREAS DRAWING INTERPRETATION C1 Ø.19 .25 .50 C .25 .50 C3
DATUM PLANE C
Ø.19
LOCATING PINS
INTERPRETATION

10. DATUM TARGET LINES DRAWING INTERPRETATION F 1.50 F1 A DATUM LINE F F1
LOCATING PIN
DATUM PLANE A

11. LOCATING GSSP MOUNTING HOLES
4X 90º
X.XXX
ØX.XXX
4XØ.XXX (X/X) THRU
.XXX-XXUNC-2B


X.XXX

12. LOCATING SIDE MOUNTING HOLES
2X X.XXX
FOR BOTTOM TAPPED HOLES, MAKE DRILL DEPTH EQUAL THREAD DEPTH
2X X.XXX
4XØ.XXX (X/X)  .XX
.XXX-XXUNC-2B  .XX



13. LOCATING COVER PLATE MOUNTING HOLES
8XØ.XXX (X/X)  .XX
.XXX-XXUNC-2B  .XX


Ø  .XX


.XXX
2X X.XXX
X.XXX
2X X.XXX
3X X.XXX
Ø  .XX
.XXX B

14. OTHER HOUSING DESIGN CONSIDERATIONS
All bores, holes, bosses, etc. (anything cylindrical) must have centerlines
Lengths and diameters of bosses must be shown
The center hole in the top of the housing must be large enough to clear the top of the yoke while shifting gears
The drain hole and filler hole must be located, but may not have to be positioned
The lower bearing bore houses a closed-end bearing. A smaller thru hole allows for removal of a worn-out bearing
All fillets and rounds must be sized, but this may be done in the title block
Define surface finishes where appropriate
Add all dimensions necessary to locate and size all features

15. FINAL EXAMINATION PREVIEW
Threads
Nomenclature (names of thread parts)
Representations (methods of drawing threads)
Complete threaded hole callouts
Number of threads per inch for given size, form, and series
Diameter of thread for a given thread specified by number
Required tap drill for given internal thread
Required position tolerance for given thread and fastener condition
Complete callout for given fastener

16. FINAL EXAMINATION PREVIEW
Threaded Fasteners
Screw feature dimensions (head thickness, width, etc.)
Matching
Match geometric symbols, modifiers, etc. to definitions
Feature Control Frames
Identify all parts of a typical feature control frame
Maximum Material Condition (MMC)
Determine MMC of hole and shaft with given dimensions
Dimension Types
Identify different types of dimensions by appearance
Dimension Classes
Know the two things that any dimension can do