Practice Problems

Mechanical Engineering 123

Visualization & CAD

Table of Contents Page

PRACTICE PROBLEMS 1

BLOCK TO ISOMETRIC 1

3 VIEW TO ISOMETRIC 5

3 VIEWS FROM ISOMETRIC 8

MODEL ISOMETRIC 10

INCOMPLETE AND MISSING VIEWS 13

SECTION VIEWS 15

TOLERANCES 18

AUXILIARY VIEW 21

DIMENSIONING 22

SOLUTIONS 24

BLOCK TO ISOMETRIC 25

3 VIEW TO ISOMETRIC 29

3 VIEWS FROM ISOMETRIC 32

MODEL ISOMETRIC 34

INCOMPLETE AND MISSING VIEWS 37

SECTION VIEWS 39

TOLERANCES 42

AUXILIARY VIEW 45

DIMENSIONING 46

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3. Sketch the corner view (from A) of the building on the isometric grid paper provided. Lines

should be drawn only for the edges of the building.

3 3 2 2 2 3 1 2 1 A

3

4. Choose the “best view” for sketching an isometric of the building shown below. Circle the letter

corresponding to the viewpoint:

A B 1 1 2

0 2 1

0 3 0 D C

4

5. Choose the “best view” for sketching an isometric of the building shown below. Circle the letter corresponding to the viewpoint:

C B

1 1 2 1

1 2 2 0

3 4 4 1

D A

5

3 View to Isometric

1. Sketch an isometric pictorial for each of the objects shown in the multiview drawing. One unit on the rectilinear grid equals one grid unit on the iso-grid. Orient the objects so that the top, front and right sides are visible on the isometric.

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7

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3 Views from Isometric

1. Sketch the top, front and right side views of the object shown below. Include centerlines and make sure you align the views according to the convention.

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Model Isometric

Draw isometrics of the objects shown below. Scale the drawing so that 1 unit on the object is equal to one unit on the isometric grid paper. Keep in mind that parallel lines of a surface will remain parallel on the isometric.

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12

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Incomplete and Missing Views

1. In each of the drawings shown below one view is incomplete. Sketch in the missing lines in the incomplete views.

2. Complete the missing view of each single solid object. Note the unconventional arrangement of views for object B. The front and top views are given and you need to draw in the left side view.

Object B:

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15

Section Views

1. Below are two identical top views and one front view. Using the front view as a guide, draw a sectioned front view on the right using the cutting plane line shown.

2. What type of section view is shown in problem 1 above. _______________________________

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3. Complete the profile view of the bearing bracket as a half-section using good conventional

practices.

4. Sketch the indicated sections view. For the last two problems you can place the sectioned front view below the front view that is given. Normally you would replace the front view.

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Tolerances 1. Sketch a side view of the shaft shown in Figure 1. Specify the horizontal dimension of each section

using datum dimensioning form the left end. The length of each horizontal section from left to right is .75, 2.00, .50, 1.25 and 3.00 inches. Base the plus and minus dimensions on the Worst expected tolerances for turning. What are the maximum and minimum dimensions for the length from the left end to the left edge of the largest diameter section? Use four digits past the decimal point to specify the tolerances, even though typical practice would be to specify only three digits past the decimal point.

2. Give limits with unilateral tolerances, using the basic hole system. Basic diameter = 0.625 Allowance = 0.000 Hole Tolerance = .0007 Shaft Tolerance = .0004

Maximum Clearance: _____________ Minimum Clearance: _____________

Check the correct fit: This is a clearance ( ), transition ( ), interference ( ).

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3. Give bilateral tolerance dimensions (equal +/-) using the

ANSI tables and basic hole system. Class RC-6 fit. Nominal size = 3/4.

Maximum Clearance: ____________ Minimum Clearance: ____________ Check the correct fit: This is a clearance ( ), transition ( ), interference ( ).

4. A steel tire is to be force fit on an iron wheel. The wheel will turn on a shaft. Complete the following informatio

a. Outside diameter of wheel ____________________ b. Inside diameter of tire _______________________ c. Inside diameter of wheel _____________________ d. Outside diameter of shaft _____________________ e. The allowance for the RC7 fit _________________ f. The tolerance of the shaft diameter _____________

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5. Dimension the part shown below using Geometric Dimensioning and Tolerance procedure so the

following functional requirements are met:

g. The datum surfaces A and B must be flat within a tolerance zone of 0.02 mm h. The surface C must be parallel to datum surfaces A and B within 0.08 mm i. The large bore must be perpendicular to datum surfaces A and B within 0.08 mm j. The sides of the 4X8 keyway must be machined. k. Indicate the datum surfaces l. The large hub must be circular within a tolerance zone of 0.02.

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Auxiliary View 1. Sketch the auxiliary view of the inclined surface in the two problems below:

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Dimensioning

1. Completely dimension the following objects according to the rules learned in class. You may use XX instead of actual numbers.

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24

Solutions

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3. Sketch the corner view (from A) of the building on the isometric grid paper provided. Lines

should be drawn only for the edges of the building.

3 3 2 2 2 3 1 2 1 A

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A B 1 1 2

2 1

3 D C

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C B

1 1 2 1 1 2 2 0 3 4 4 1

D A

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3 View to Isometric

1. Sketch an isometric pictorial for each of the objects shown in the multiview drawing. One unit on the rectilinear grid equals one grid unit on the iso-grid. Orient the objects so that the top, front and right sides are visible on the isometric.

30

31

32

3 Views from Isometric

2. Sketch the top, front and right side views of the object shown below. Include centerlines and make sure you align the views according to the convention.

33

34

Model Isometric

Draw isometrics of the objects shown below. Scale the drawing so that 1 unit on the object is equal to one unit on the isometric grid paper. Keep in mind that parallel lines of a surface will remain parallel on the isometric.

35

36

37

Incomplete and Missing Views 1. In each of the drawings shown below one view is incomplete. Sketch in the missing lines in the

incomplete views.

2. Complete the missing view of each single solid object. Note the unconventional arrangement of views for object B. The front and top views are given and you need to draw in the left side view.

Object B:

38

39

Section Views

1. Below are two identical top views and one front view. Using the front view as a guide, draw a sectioned front view on the right using the cutting plane line shown.

2. What type of section view is shown in problem 1 above. __HALF SECTION__

40

3. Complete the profile view of the bearing bracket as a half-section using good conventional

practices.

4. Sketch the indicated sections view. For the last two problems you can place the sectioned front view below the front view that is given. Normally you would replace the front view.

41

42

Tolerances 1. Sketch a side view of the shaft shown in Figure 1. Specify the horizontal dimension of each section

using datum dimensioning form the left end. The length of each horizontal section from left to right is .75, 2.00, .50, 1.25 and 3.00 inches. Base the plus and minus dimensions on the Worst expected tolerances for turning. What are the maximum and minimum dimensions for the length from the left end to the left edge of the largest diameter section? Use four digits past the decimal point to specify the tolerances, even though typical practice would be to specify only three digits past the decimal point.

2. Give limits with unilateral tolerances, using the basic hole system. Basic diameter = 0.625 Allowance = 0.000 Hole Tolerance = .0007 Shaft Tolerance = .0004

Maximum Clearance: 0.0011 Minimum Clearance: 0.0000

Check the correct fit: This is a clearance (X), transition ( ), interference ( ).

Allowence = min clearance = 0.000= smallest hole – largest shaft .625 .625 Max Clearance = 6.2507

-6.2496 .0011

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3. Give bilateral tolerance dimensions (equal +/-) using the

ANSI tables and basic hole system. Class RC-6 fit. Nominal size = 3/4.

Maximum Clearance: .0048 Minimum Clearance: .0016 Check the correct fit: This is a clearance (X), transition ( ), interference ( ). Check: .7520 .7500 .7472 .7484 .0048 .0016

4. A steel tire is to be force fit on an iron wheel. The wheel will turn on a shaft. Complete the following informatio

m. Outside diameter of wheel: 10.020 – 10.018 n. Inside diameter of tire: 10.000 – 10.003 o. Inside diameter of wheel: .7500 - .7520 p. Outside diameter of shaft: .7475 - .7463 q. The allowance for the RC7 fit: .0025 r. The tolerance of the shaft diameter: .0012

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5. Dimension the part shown below using Geometric Dimensioning and Tolerance procedure so the

following functional requirements are met:

s. The datum surfaces A and B must be flat within a tolerance zone of 0.02 mm t. The surface C must be parallel to datum surfaces A and B within 0.08 mm u. The large bore must be perpendicular to datum surfaces A and B within 0.08 mm v. The sides of the 4X8 keyway must be machined. w. Indicate the datum surfaces x. The large hub must be circular within a tolerance zone of 0.02.

45

Auxiliary View 1. Sketch the auxiliary view of the inclined surface in the two problems below:

46

Dimensioning

1. Completely dimension the following objects according to the rules learned in class. You may use XX instead of actual numbers.

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