Instructor:Instructor:

James ThornburghJames Thornburgh

Unit 1Unit 1GD&TGD&TUnit 1Unit 1GD&TGD&T

Agenda:Agenda:Inspection & GaugingInspection & Gauging

5 Steps to GD&T5 Steps to GD&TGD&T in AutoCADGD&T in AutoCAD

STPSTP

Inspection & GaugingInspection & Gauging

Functional GaugingFunctional Gauging Using Fixtures to check a partUsing Fixtures to check a part Go/ No-Go GaugesGo/ No-Go Gauges

Open GaugingOpen Gauging Using Measurements to inspectUsing Measurements to inspect Tells you what is WrongTells you what is Wrong

Feature of SizeFeature of Size Things that can be directly measuredThings that can be directly measured

Functional GaugingFunctional Gauging

15.500

10.000

11.200 ± .002

15.500

10.000

C

B

11.200 ± .002

.001 M A B C

Note: Datum A forms the bottom surface of the hole, and so the tolerance zone is a perfect, right cylinder – resting on Datum A and located from Datum B and Datum C.

A

15.500

10.000

C

B

11.200 ± .002

.001 M A B C

A

It tells us the size and shape of the tolerance zone for the hole center

In this case, when the hole is at its’ smallest permissible size, the feature location is in its’ most critical state.

15.500

10.000

C

B

11.200 ± .002

.001 M A B C

A

C

B

11.200 ± .002

.001 M A B C

In this case, when the hole is at its’ smallest permissible size and perfectly located, the feature is in its’ most critical state, and just fits about the red gage pin.

A

Produced Produced Hole SizeHole Size

Geometric Geometric ToleranceTolerance

Feature Size Feature Size ‘Bonus’‘Bonus’

Total Total Effective Effective ToleranceTolerance

11.19711.197 out of size toleranceout of size tolerance

11.19811.198 .001.001 00 .001.001

11.19911.199 .001.001 .001.001 .002.002

11.20011.200 .001.001 .002.002 .003.003

11.20111.201 .001.001 .003.003 .004.004

11.20211.202 .001.001 .004.004 .005.005

11.20311.203 out of size toleranceout of size tolerance

B

C

15.500

10.000 11.200 ± .002

.001 M A B C

M

5 Steps5 Steps

1.1. Isolate & define functionIsolate & define function

2.2. Prioritize the FunctionsPrioritize the Functions

3.3. Identify Datum Reference FrameIdentify Datum Reference Frame

4.4. Select proper ControlSelect proper Control

5.5. Calculate Tolerance ValuesCalculate Tolerance Values

GD&T in AutoCADGD&T in AutoCAD

MenuMenu DimensionDimension

ToleranceTolerance

KeyboardKeyboard toltol

GD&T Dialog BoxGD&T Dialog BoxDiameterDiameter

Material ConditionMaterial Condition

GD&T Dialog BoxGD&T Dialog Box

STPSTP

Statistical Process ControlStatistical Process Control Process for checking the quality of partsProcess for checking the quality of parts Keeps track of trends in productionKeeps track of trends in production

ANSI Limits and FitsANSI Limits and Fits

Running & SlidingRunning & Sliding Allow clearance space for lubricationAllow clearance space for lubrication RCRC

LocationalLocational Between mating partsBetween mating parts LC, LT, LNLC, LT, LN

ForceForce Tight fitsTight fits FNFN Appendixes 7-11Appendixes 7-11

Lab AssignmentsLab Assignments

LabLab Prob 16.2-16.4Prob 16.2-16.4