gd&t self evaluation test_level 9____9a1994-t09-t01a-reva

8/6/2019 GD&T Self Evaluation Test_Level 9____9a1994-T09-T01A-RevA

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GD&T SELF EVALUATION TEST - DIFFICULTY LEVEL - 9 (of 10)GD&T SELF EVALUATION TEST - DIFFICULTY LEVEL - 9 (of 10)Reference ASME Y14.5M - 1994 by David Hebert (GD&T Senior Level Certified but not associated with ASME) Test # - 1994-TL9-T01A-RevA

AB

If errors are found, or if you have any questions, please let me know..http://www.mygdtsite.com

D

C

8/1/2011 1

To use these test you simply run the slide show and use the down

arrow key to navigate. If you find any mistakes please let me know and I will fix

them and post the updated file to the www.mygdtsite.com. The part number

above reflects the current rev. Hope this helps, let me know!

Dave Hebert (Senior Level GD&T Professional)Note: these tests are not associated with ASME


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AB


D

C

8/1/2011 2

Yes

No

Can the datum reference to B allowextra positional tolerance to the

given Positional tolerance?

Section 5.3.2.2

ASME 1994 Y14.5M


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AB


D

C

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Yes

No

The specification as shown does not follow the

Standard. Datum B can not be referenced at MMC.

Can datum shift be used

here to allow more

misalignment than the given

Positional tolerance?

Section 1.3.17

ASME 1994 Y14.5M


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AB


D

C

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Yes

Can the datum reference to B allow more misalignment than

the given Positional tolerance?

No

Section 5.3.2.2

ASME 1994 Y14.5M


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AB


D

C

How do you

limit Bonus Tolerance?

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Under the FEATURE CONTROL FRAME add the words MAX BONUS TOL .005 (for .005 bonus

tolerance)Look at the sketch above and notice the added section before the datum callout. This is the

way to place a limit for the perpendicularity tolerance.

You have to work it out mathematically using the geometric tolerance and the material

condition modifiers.

After the geometric tolerance in the FEATURE CONTROL FRAME add the word MAX .005


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AB


D

C

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Which of the following is the formula for

FLOATING FASTERNERS?

T = H + F

H = T - F

H = F - T

T = H - F

T = H - F(see appendix B2 for technical description)

Positional Tolerance = (MMC) smallest Hole (MMC) largest Fastener


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AB


D

C

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The Floating fastener formula can only be

used under the following scenario?

Fasteners are same diameter + Clearance holes are same diameter + Positional tolerances

are the same.

Fasteners are same diameter + Clearance holes are MMC + Positional tolerances are the

same.

Fasteners are same diameter + Clearance holes are RFS + Positional tolerances are the same.

Fasteners are same diameter + Clearance holes are LMC + Positional tolerances are the same.


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AB


D

C

8/1/2011 9


FIXED FASTERNERS?

H = F (T1 + T2)

F = H + T1 + T2

F + T1 = H + T2

T1 + T2 = H - F

T1 + T2 = H - F

(see appendix B2 for technical description)

Allowable positional tolerance is as follows:

Pos. Tol (1) + Pos. Tol (2) = (MMC) smallest Ho le (MMC) largest Fastener


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AB


D

C

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FIXED FASTERNERS with added compensation

for a positional tolerance that doesnt specify a projected

tolerance zone.

H = F + T1 + T2 (1 + (2P/D))

H = F + T1 + T2 (1 / (2P/D))

H = F + T1 + T2 (1 + (4P/D))

H = F + T1 + T2 (1 - (2P/D))

H = F + T1 + T2 (1 + (2P/D))

(same as fixed fastener except for the compensation factor

attached to the Pos. Tol. of the tapped hole. This is needed due

to errors from tapped holes that are not perfectly perpendicular)


11/27


AB


D

C

If only the compensation section of the formula is appliedto the following, how much more positional tolerance is

required for the tapped holes?Reference H = F + T1 + T2 (1 + (2P/D))

Depth = 4

Projection = 1

Depth = 3

Projection = 1

Depth = 1

Projection = 1

Depth = 2

Projection = 1

(1+(2*1)/4)) = 1.5X more positional tolerance required for tapped holes

(1+(2*1)/3)) = 1.67X more positional tolerance required for tapped holes

(1+(2*1)/2)) = 2X more positional tolerance required for tapped holes

(1+(2*1)/1)) = 3X more positional tolerance required for tapped holes

A

DB

C


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AB


D

C

It may be helpful for this exercise to think of a surface plate or flat piece of manufacturing equipmentto look similar to the jagged line shown below because at a microscopic level it probably is.

What is the theoretical Plane of a Datum Feature called?

Datum Plane its the TGC (theoretical geometric counterpart) of the datum feature

A

TheoreticalActual surface (surface plate or part)

Whats the theoretical Plane derived from the Datum Feature Simulator(surface plate) called?B What is the actual surface of a Part called (in regards to Datum's)?C Whats the actual surface of a Surface Plate (for example) called (regards to datum's)?D

Simulated Datum Plane

Datum Feat re

Simulated Datum Feat re Surface of the Surface plate or Machine Surface)


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AB


D

C

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Actual size

Actual local size

Actual mating size

Nominal sizeResultant condition size

Virtual condition size

Constant (no bonus)

How big/small it acts

Cross section (2d)

Variable (bonus+)Just a name

Actual Part

Match the words in the left column

to those in the right column.


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AB


D

C

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What is the Datum Feature

Simulator?

The axis of the of the part.

Ring Gauge

The ring gauge.

The surface of the OD of the of the part.

The surface of the ID of the ring.


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AB


D

C

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While inspecting a part the inspector went through the processof finding a precision ground pin that fit tightly in a drilled hole

(shown in red). Is this method called:

A - Circumscribed

B - Resultant condition methodC - Inscribed

D Virtual condition method

Inscribed the pin touches on all the high spots of the inside of the hole.

Pin


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A

B


D

C

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Can you use a precision ground gauge pin in this manner to

determine if a hole in a part is too large?

A - YES

B - NO

No, you cannot detect lobes (as shown above in blue) with a pin.

Pin


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A

B


D

C

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If you only used a gauge pin to check the spec on this hole

what information did you uncover about the hole?

Straightness of the hole.

Pin

The geometric counterpart of that feature.

The actual mating size.

Both B and C.


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A

B


D

C

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While inspecting a part the inspector went through the process

of finding a Ring Gauge that fit tightly around the outside

diameter of a feature (shown in red). Is this method called:

A - Circumscribed method

B - Radial measuringC - diametrical measuring

D Ring Method

Cirumscribed the Ring Gauge touches on all the high spots of the outside

of the feature (smallest circumscribed cylinder).

Ring Gauge


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A

B


D

C

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What is the True Geometric

Counterpart in the sketch

to the right:

The axis of the of the part.

Ring Gauge

The axis of the of the ring.

OD of the of the part.

ID of the ring.


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A

B


D

C

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What is the True geometric counterpart in the sketch below. This

is a precision ground vice holding a part to be measured.

The mid plane of both faces of the vise jaws .

Both faces of the vise jaws.

The face of the solid jaw (jaw that doesnt move).

The face of the part that is up against the face of the solid jaw.

Datum


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A

B


D

C


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In this case, the vice is being used as a

______ _______ _________.



In this case, the vice is being used as a

Datum Feature Simulator

Datum Feature Simulator

Datum


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A

B


D

C

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Which center line defines the mid plane

of the true geometric counterpart of thepart shown below?

A B

The mid plane of two parallel planes (faces of the jaws here) at minimum

separation.

Datum


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A

B


D

C

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Which center line defines the derived

median plane of the feature?

A B

Datum


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A

B


D

C

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Which center line defines the center

plane of the feature?

Datum

A B


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A

B


D

C

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When a deep hole is drilled in a part

there is a tendency for the drill to walk.

This result of a crooked drilled hole can

be seen in the assembly on the right (in

blue). GD&T has a positional tolerance

zone shape that can deal with this. Whatis the name of the tolerance zone?

The mid plane of both faces of the vise jaws .




A conical tolerance zone


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A

B


D

C

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Please supply the answers to the following:

MMC of the hole = _________

LMC of the hole = __________

Possible Datum Shift = ________

Virtual Condition = __________

Resultant condition if actual hole size is 5.2 diameter = _____

Possible Bonus Tolerance = __

Is Datum Plane A a mid plane (Y/N) = __

What is the material condition for the 5mm modified at?______

5.0

5.5

1.0

0

.0

6.

Y

RFS

gd&t self evaluation test_level 9____9a1994-t09-t01a-reva

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