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ME152

Tables & Supplemental Information

by Roger L. Ludin

ME152 Engineering Design Communications II Instructor ______________________ Office - __________, Phone - 756-__________ e-mail - ____________@calpoly.edu Web Page: Office Hours: ___________________

Texts: Technical Drawing, 5th Ed. Goetsch et al. ME152 Homework and Laboratory Assignments Packet, Ludin, Optional: Introduction to Solid Modeling, Howard &Musto Prerequisite: ME151

Class Topic Read before class

Homework Due next Lecture

Lecture 1

Lab 1

Dimensioning Practices for Communicating; Manufacturing Information Introduction to Computer Lab and CAD

Ch 10 P389-416

LM p1:2, 2:1-3

Sh. 1, 2, 3

Lab 1 Lecture 2

Lab 2

Tolerancing Theory and Techniques for Engineering Production Computer Techniques

Ch 10 P416-429

LM p1:11-13,2:21-26

Sh. 4, 5

Lab 2

Lecture 3

Lab 3

Geometric Dimensioning & Tolerancing Computer Techniques

Ch 12 P484-519

LM p2:1-20

Sh. 6, 7

Lab 3 Lecture 4

Lab 4

Threaded Fasteners; Thread Forms and Sizes; Thread Representation Computer Techniques

Ch 13 P529-541

LM p1:3-10

Sh. 8, 9

Lab 4 Lecture 5

Lab 5

Detail Drawings; Layout Drawings Computer Techniques

Ch 17 P627-631

LM p1:2,2:1-26

Sh. 10, 11

Lab 5 Lecture 6

Lab 6

Assembly Drawings & Practices; Design for Assembly; ECO’s; Hierarchy of Drawings Computer Techniques

Ch 17 P631-647

LM p2:1-14

Sh. 12,13,14

Lab 6 Lecture 7

Lab 7 Introduction of Project; Design Analysis; Design Reviews Computer Techniques; Project Work

Sh. 15 Lab 7

Lecture 8

Lab 8

Welding Practices; Weld Symbols; Design of Weldments Computer Techniques; Project Work

Ch 19 P716-735

LM p1:14-15

Sh. 16,17

Lab 8 Lecture 9

Lab 9 Review Computer Techniques; Project Work

Lab - Project

Lecture 10 Lab 10

Final Exam in Lecture Final Exam in Lab

Grading: Homework 20%, Quizzes 10%, Lab Assignments 20%, Lecture Final 20%, Lab Final 20%, Project 10% Equipment Required: Manual drafting equipment for homework assignments (pencils, triangles, templates, scales, etc. - same as you used in ME151.) You will need a flash drive to save your electronic files. Bring it to every lab. It is your responsibility of keeping copies of your work in case a file was misplaced. Bring a ruler to every lab and lecture. Workbook homework is due at the BEGINNING of lecture. No late HW will be accepted. Staple your homework. Include your name and lecture section. Five points are deducted for unstapled homework or labs. Laboratory Assignments: Lab assignments will be due at the beginning of the next lab period, although many of the labs may be completed in the regular lab period. Some assignments will be due the following week. No late work is accepted. Include your name, lab section, and lab assignment number. Attendance: Lecture and laboratory attendance is required. Quizzes in both lecture and lab will be given in the first 5 minutes of each class and lab so be on time. There are no make-up quizzes or exams and no extra credit assignments. In emergencies, please contact your instructor as soon as possible. Work you miss may be excused for “serious and compelling reasons”. Please bring documentation. All the work you hand in must be your own, original work. File swapping is not permitted. Ethical behavior is expected in all aspects of the course.

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Path to Success in ME152 Here are some hints which, if followed, will increase your success rate in ME152.The first and biggest suggestion is to read all materials carefully. The first 30 or so pages of the lab manual contains a wealth of information about areas the text is weak on, tables not found in the text and a description of SolidWorks. Much of this description was written after SolidWorks was used for a quarter and certain problem areas that arose with students are addressed. What was put in the lab manual was not intended to replace the text book. There is a wealth of information in the text, and the assigned reading is put in the course for a purpose. It is impossible to cover all the material in lecture and what is covered cannot all be remembered, so the text is used to reinforce the lectures and to help jog the memory. Also, there are many tables in the appendix which are necessary for the course. You will be expected to be able to read the fit tables, interpret thread charts and find standard fastener dimensions. You will not be told to use a certain table, you will be expected to find the correct one, so look through the tables and acquaint yourself with what is there. It seems trivial to have to say do all the assigned homework and lab exercises. These compromise 40% of your grade. It is better to turn in an unfinished assignment than to turn in nothing at all. A blank in the grade book is a statement that you do not care. Many of the homework assignments will be discussed in class to give you a better idea of what is expected. If you are still not clear, see me. If you cannot make office hours, feel free to stop by the lab in 20-150 to ask questions, even if it is not your lab time. I am usually free to help you after the first hour or so. My schedule is posted outside my office. Listen in lecture. When you hear “This must be done” it is not a suggestion to do it if you feel like it. Note it down and use the method that is demanded. In many cases there are several correct methods, but often one certain method will be required for uniformity or for preparation for later work. The course is not about SolidWorks. SolidWorks is just the CAD selected to bring the topic covered in lecture to fruition. Each week more of the program will be added to your knowledge base. There are several steps which I demand be followed and the demos show exactly how to do them. Making sure all your features are fully defined before extruding avoids problems down the road as you bring parts into assemblies. Renaming features is equivalent to documenting a computer program. The program will run without it, but no one else will be able to interpret it. As I have to “read” your parts electronically, I insist on this renaming. It is not busy work, but critical as your parts become more complex. “Cut-Extrude 38” means nothing, but “Slot for Slider” says what the feature is. In all the demonstrations these steps are rigorously followed. By not following these simple steps week after week, students lost enough points to drop their about a letter. Also, whenever you deal with dimensions you should automatically create a dimension layer. Each laboratory has an associated demonstration, which will be worked through at the beginning of the lab, and all the steps will be explained. You should work along with it. The steps are all listed in the manual. Make notations on the various important steps. Check point files are available. If you fall behind, open the next check point and pick up with the class. Fill in the hole later. Don’t be afraid to ask questions if you are not clear of any steps. In grading the electronic versions of the labs I encounter several common errors. Rather than write out these errors such as “Don’t dimension to hidden lines” over and over, I use abbreviations. In the lab manual is a page with a list of these abbreviations of common errors. Look through the list and see what the common errors are, then look through your labs any of the errors and fix them before submitting your work. Or, better yet, fix them as you create your parts and drawings. The project at the end of the course is the one time you are asked to bring everything learned in the course together. How these items are incorporated in the drawings and assemblies will be looked at closely. Are the drawings numbered properly? Are the fits dimensioned and calculated correctly? Do you have proper thread callouts? Is the BOM the correct size, order and are the balloons properly attached? Are the drawings and assemblies clear and readable? These are the questions asked. You are not being graded on how well or innovative your design is as long as it is close to functioning. In other words, the project is for you to demonstrate that you can apply the important points covered in the class.

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Course Objectives for ABET Assessment (Accreditation Bureau for Engineering and Technology)

• The student will be able to construct engineering communication documents

describing mechanical devices and systems by using points, vectors and surfaces. Multiview, isometric and oblique drawings will be used as appropriate for manufacturing processes.

• The student will be able to plan, construct and read engineering communication documents that describe how a mechanical part will be made, and give appropriate information to provide quality control in mass production. Techniques used will be standard practice in current industrial use.

• The student will be able to define and communicate dimensions for engineering parts of mechanical components following current industrial standards.

• The student will become familiar with a common industrial CAD package and use it to create engineering documentation.

Catalog Course Description Advanced communication principles will be used to communicate project design to manufacturing processes. The projects will be evaluated in terms of meeting the design criteria. Techniques of advanced communication methods will be explored to enhance reliability and quality assurance of products and subsystems. The use of computers to enhance these processes will also be explored. 1 Lecture and 1 Laboratory.

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ANSI (English) Thread Callouts:

External Thread Callouts 1. General Identification of

Fastener 2. Type of Head 3. Classification of Fastener 4. Nominal size in fractions 5. Threads per inch (TPI) 6. Series – (Unified National Acme, Square, Knuckle) 7. Type of Thread C – Coarse thread

F – Fine Thread EF – Extrafine Thread 8. Class of Fit 1. – Loose Fit 2. – Average Fit 3. – Tight fit 9. A indicates external threads 10. Length of screw or bolt Between 9 and 10 place any qualifiers such as LH for left hand thread or double for double threads etc.

Internal Threads 4-8. Same as external 11. B indicates internal threads 12. Depth symbol (Omitted for thru)

13. Depth of thread (4 threads added on in drilling for tapered tap.)

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The pitch of a thread is the distance between the threads. This value is given in a metric callout. In the English callout the pitch is the reciprocal of the threads per inch. The lead of a screw is the distance it advances in one revolution. For normal threads this is the same as the pitch. For double threads the lead is twice the pitch, for triple, three times, etc. A typical arrangement is to have a screw fasten two plates together. The screw must pass cleanly through the upper plate with some clearance. This plate may not be threaded. If it is then the two plates will not be able to be snugged together. The top plate may also be counter bored or countersunk to accommodate the head of the fastener. The lower plate is threaded and may be either a through hole or a blind hole. The internal threads of the lower plate must be the same as the upper. In this example a ½-13 screw is being used to fasten two plates. The callout tells us that it is an socket head cap screw, 2 inches long with a Unified National coarse thread and an average fit. This type of head must be counterbored. The clearance plate is 1 inch thick. The through hole is .53 inches in diameter thus allowing a .03 clearance for the screw. The counterbore says that the head diameter is .75 and its height is .50 inches. The callout for the blind hole indicates that the thread is the same, ½ - 13 and the B indicates that it is internal. The threads go to a depth of 1.5 inches. The machinist will drill a hole four threads deeper (.3) inches to allow for the taper of the tap. If this were a through hole instead of a blind hole the callout would stop after the 2B. If no depth is specified, the default is thru. This example utilizes a simplified representation for the screw and the hole.

Note that the length of the screw is measured differently for different screws. Screws with an angled head like the oval head or a flat head screw were designed to be countersunk so the length is measured from the top of the angled area. Hex head screws and round head screws have their heads above the material so their length is measured from the bottom of the head. If counterbored, the height of the screw head must be added to its length to get the total depth of penetration.

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Metric Threads

Bolt - Cross Pt Pan HeadM10 x 1.5 6g x 40

Hex NutM10 x 1.5 6H

1

2 3 4 56 2 3 4 7

External Thread Internal Thread

Metric thread call out notation 1. General Identification of fastener and type of head or nut 2. M denotes metric thread 3. Diameter in mm 4. pitch of thread in mm 5. Length of screw in mm

6.Thread tolerance (g – external) 4g – tight fit 6g – medium fit 8g – free fit 7. Thread tolerance (H– internal) 5H – tight fit 6H – medium fit 7H – free fit

Representation of threads in simplified and schematic forms for external and internal. Note that unsectioned views have only one representation.

Schematic Simplified End View

SectionSchematic

SectionSimplified

UnsectionedBoth

End View

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Acme Threads

Acme Thread Call Out Notation 4 and 5 Class of Fit 1. Major diameter in inches. 4. Allowance (2 preferred, 3 or 4 loose) 2. Threads per inch. 5. G = General, C = Centralized. 3. Acme thread profile A general fit has clearances at both the major and minor diameters. The screw and nut contacts take place on the thread flanks. The centralized fit also has contacts on the major and minor diameters. For axial loading either may be used. Centralized is preferred for transverse loading. As ACME threads are used for specialized cases, the length of the thread is usually placed directly on the part rather than in the callout. Also internal and external is deduced from the drawing. There is no coarse, fine or extra-fine designations in the callouts as they only apply to UNC threads.

Holes When placing either clearance or tapped holes for fasteners in a part, place the center of the hole a least a diameter of the hole away from any edge for strength purposes. A hole closer to the edge will be weak an prone to breakage. When placing holes in rods, the general rule of thumb is to have the diameter of the hole at most half the diameter of the rod, again for strength purposes.

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Thread Standards

These are the standard dimensions for the common threads encountered. The pitch is the reciprocal of the number of threads per inch. The minor diameter may be computed from the major diameter and the pitch, i.e. the UN minor diameter may be found by:

φminor = φmajor – 2*.65*pitch The other minor diameters are found in a like manner.

Unified National (UN) Threads

Square Threads

IOS (metric) Threads

Acme Threads

Knuckle Threads

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Lengths For Threaded Fasteners Diameter Length

1/4 5/16 3/8 7/16 1/2 9/16 5/8 3/4 '7/8 1.00 1.25 1.50 1.75 2.00 2.50 3.00 3.50 4.00

5(.125) • • • • • • • • • • • 6(.138) • • • • • • • • • • • • • 8(.164) • • • • • • • • • • • • •

10(.190) • • • • • • • • • • • • • • 12(.216) • • • • • • • • • • • •

1/4 • • • • • • • • • • • • • • • 5/16 • • • • • • • • • • • • • • •

3/8 • • • • • • • • • • • • • • • • 7/16 • • • • • • • • • • • • • • • •

1/2 • • • • • • • • • • • • • • • • • • 9/16 • • • • • • • • • • • • • •

5/8 • • • • • • • • • • • • • • 3/4 • • • • • • • • • • • • 7/8 • • • • • • • • •

1 • • • • •

Lengths for Metric Fasteners Diameter Length

4 5 8 10 12 16 20 24 30 36 40 45 50 60 701.6 • • •

2 • • • 2.5 • • • • •

3 • • • • 4 • • • • • 5 • • • • • • 6 • • • • • 8 • • • • • • •

10 • • • • • • • • • 12 • • • • • • • • • • 16 • • • • • • • • • 20 • • • • • • • • 24 • • • • • • • 30 • • • • • •

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Acme Thread Pitch Square Thread Pitch

Standard Sizes

Size TPI Major Diam Minor Diam 1/4 16 0.2500 0.1875 5/16 14 0.3125 0.2411 3/8 12 0.3750 0.2917 7/16 12 0.4375 0.3542 1/2 10 0.5000 0.4000 9/16 10 0.5625 0.4625 5/8 8 0.6250 0.5000 3/4 6 0.7500 0.5833 7/8 6 0.8750 0.7083 1 5 1.0000 0.8000

1-1/8 5 1.1250 0.9250 1-1/4 5 1.2500 1.0500 1-3/8 4 1.3750 1.1250 1-1/2 4 1.5000 1.2500 1-3/4 4 1.7500 1.5000

2 4 2.0000 1.7500 2-1/4 3 2.2500 1.9167 2-1/2 3 2.5000 2.1667 2-3/4 3 2.7500 2.4167

3 2 3.0000 2.5000 3-1/2 2 3.5000 3.0000

4 2 4.0000 3.5000 4-1/2 2 4.5000 4.0000

5 2 5.0000 4.5000

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O Ring Standard Sizes AS568A Nominal Size (in) Actual Size (in) Dash No. I.D. O.D. W I.D. W

-001 -002 -003 -004 -005 -006 -007 -008 -009 -010 -011 -012 -013 -014 -015 -016 -017 -018 -019 -020 -021 -022 -102 -103 -104 -105 -106 -107 -108 -109 -110 -111 -112 -113 -114 -115 -116 -117 -118 -119 -120 -201 -202 -203 -204 -205 -206 -207 -208 -209 -210 -211 -212 -213 -214

1/32 3/64 1/16 5/64 3/32 1/8 5/32 3/16 7/32 1/4 5/16 3/8 7/16 1/2 9/16 5/8

11/16 3/4

13/16 7/8

15/16 1

1/16 3/32 1/8 5/32 3/16 7/32 1/4 5/16 3/8 7/16 1/2 9/16 5/8

11/16 3/4

13/16 7/8

15/16 1

3/16 1/4 5/16 3/8 7/16 1/2 9/16 5/8

11/16 3/4

13/16 7/8

15/16 1

3/32 9/64 3/16 13/64 7/32 1/4 9/32 5/16 11/32 3/8 7/16 1/2 9/16 5/8

11/16 3/4

13/16 7/8

15/16 1

1-1/16 1-1/8 1/4 9/32 5/16 11/32 3/8

13/32 7/16 1/2 9/16 5/8

11/16 3/4

13/16 7/8

15/16 1

1-1/16 1-1/8 1-3/16 7/16 1/2 9/16 5/8

11/16 3/4

13/16 7/8

15/16 1

1-1/16 1-1/8 1-3/16 1-1/4

1/32 3/64 1/16 1/16 1/16 1/16 1/16 1/16 1/16 1/16 1/16 1/16 1/16 1/16 1/16 1/16 1/16 1/16 1/16 1/16 1/16 1/16 3/32 3/32 3/32 3/32 3/32 3/32 3/32 3/32 3/32 3/32 3/32 3/32 3/32 3/32 3/32 3/32 3/32 3/32 3/32 1/8 1/8 1/8 1/8 1/8 1/8 1/8 1/8 1/8 1/8 1/8 1/8 1/8 1/8

.029±.004

.042±.004

.056±.004

.070±.005

.101±.005

.114±.005

.145±.005

.176±.005

.208±.005

.239±.005

.301±.005

.364±.005

.426±.005

.489±.005

.551±.007

.614±.009

.676±.009

.739±.009

.801±.009

.864±.009

.926±.009

.989±.010

.049±.005

.081±.005

.112±.005

.143±.005

.174±.005

.206±.005

.237±.005

.299±.005

.362±.005

.424±.005

.487±.005

.549±.007

.612±.009

.674±.009

.737±.009

.799±.010

.862±.010

.924±.010

.987±.010

.171±.005

.234±.005

.296±.005

.359±.005

.421±.005

.484±.005

.546±.007

.609±.009

.671±.009

.734±.010

.796±.010

.859±.010

.921±.010

.984±.010

.040±.003

.050±.003

.060±.003

.070±.003

.070±.003

.070±.003

.070±.003

.070±.003

.070±.003

.070±.003

.070±.003

.070±.003

.070±.003

.070±.003

.070±.003

.070±.003

.070±.003

.070±.003

.070±.003

.070±.003

.070±.003

.070±.003

.103±.003

.103±.003

.103±.003

.103±.003

.103±.003

.103±.003

.103±.003

.103±.003

.103±.003

.103±.003

.103±.003

.103±.003

.103±.003

.103±.003

.103±.003

.103±.003

.103±.003

.103±.003

.103±.003

.139±.004

.139±.004

.139±.004

.139±.004

.139±.004

.139±.004

.139±.004

.139±.004

.139±.004

.139±.004

.139±.004

.139±.004

.139±.004

.139±.004

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E Ring – Retaining Rings

Carbon Steel H G W D0 D1 F T

Part # Shaft

Diameter Groove

DiameterGroove Width

Outer Ring D

Middle Diameter

Free Diameter

Ring Thickness

E-6SPTA 0.062 0.052 0.012 0.102 0.083 0.051 0.010 E-9SPTA 0.094 0.074 0.020 0.146 0.118 0.073 0.015 E-12SPTA 0.125 0.095 0.020 0.188 0.152 0.094 0.015

SE-14SPTA 0.140 0.102 0.020 0.200 0.162 0.100 0.015 E-15SPTA 0.156 0.116 0.029 0.288 0.185 0.114 0.025

SE-17SPTA 0.172 0.127 0.029 0.250 0.203 0.125 0.025 E-18SPTA 0.188 0.147 0.029 0.290 0.235 0.145 0.025

SE-21SPTA 0.219 0.188 0.029 0.370 0.300 0.185 0.025 E-25SPTA 0.250 0.210 0.029 0.414 0.336 0.207 0.025

SE-31SPTA 0.312 0.250 0.029 0.486 0.394 0.243 0.025 E-37SPTA 0.375 0.303 0.039 0.600 0.486 0.300 0.035 E-43SPTA 0.438 0.343 0.039 0.674 0.546 0.337 0.035 E-50SPTA 0.500 0.396 0.046 0.784 0.636 0.392 0.042 E-62SPTA 0.625 0.485 0.046 0.960 0.778 0.480 0.042

SE-74SPTA 0.750 0.625 0.056 1.232 0.999 0.616 0.050 E-87SPTA 0.875 0.675 0.056 1.326 1.083 0.668 0.050

SE-98SPTA 0.984 0.835 0.056 1.644 1.333 0.822 0.050 SE-118STPA 1.118 1.079 0.068 2.132 1.729 1.066 0.062

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Socket Head Cap Screw

Body Diameter Head Diameter Head Height Hex. Socket

Size Fillet Ext.

Key En-gage-ment

Max Min Max Min Max Min Nom Nom Max Min

Nominal Size

D A H J F T 0 0.0600 0.0568 0.096 0.091 0.060 0.057 0.050 0.007 0.025 1 0.0730 0.0695 0.118 0.112 0.073 0.070 1/16 0.062 0.007 0.031 2 0.0860 0.0822 0.140 0.134 0.086 0.083 5/64 0.078 0.008 0.038 3 0.0990 0.0949 0.161 0.154 0.099 0.095 5/64 0.078 0.008 0.044 4 0.1120 0.1075 0.183 0.175 0.112 0.108 3/32 0.094 0.009 0.051 5 0.1250 0.1202 0.205 0.198 0.125 0.121 3/32 0.094 0.010 0.057 6 0.1380 0.1329 0.226 0.218 0.138 0.134 7/64 0.109 0.010 0.064 8 0.1640 0.1585 0.270 0.262 0.164 0.159 9/64 0.141 0.012 0.077 10 0.1900 0.1840 0.312 0.303 0.190 0.185 5/32 0.156 0.014 0.090

1/4 0.2500 0.2435 0.375 0.365 0.250 0.244 3/16 0.188 0.014 0.120 5/16 0.3125 0.3053 0.469 0.457 0.313 0.306 1/4 0.250 0.017 0.151 3/8 0.3750 0.3678 0.562 0.550 0.375 0.368 5/16 0.312 0.020 0.182

7/16 0.4375 0.4294 0.656 0.642 0.438 0.438 3/8 0.375 0.023 0.213 1/2 0.5000 0.4919 0.750 0.735 0.500 0.492 3/8 0.375 0.026 0.245 5/8 0.6250 0.6163 0.938 0.921 0.625 0.616 1/2 0.500 0.032 0.307 3/4 0.7500 0.7406 1.125 1.107 0.750 0.740 5/8 0.625 0.039 0.370 7/8 0.8750 0.8647 1.312 1.293 0.875 0.864 3/4 0.750 0.044 0.432 1 1.0000 0.9886 1.500 1.479 1.000 0.988 3/4 0.750 0.050 0.495

1 1/8 1.1250 1.1086 1.688 1.665 1.125 1.111 7/8 0.875 0.055 0.557 1 14 1.2500 1.2336 1.875 1.852 1.250 1.236 7/8 0.875 0.060 0.620 1 3/8 1.3750 1.3568 2.062 2.038 1.375 1.360 1 1.000 0.065 0.682 1 1/2 1.5000 1.4818 2.250 2.224 1.500 1.485 1 1.000 0.070 0.745 1 3/4 1.7500 1.7295 2.625 2.597 1.750 1.734 1 1/4 1.250 0.080 0.870

2 2.0000 1.9780 3.000 2.970 2.000 1.963 1 1/4 1.500 0.090 0.995

2 1/4 2.2500 2.2280 3.375 3.344 2.250 2.232 1 3/4 1.750 0.100 1.200 2 1/2 2.5000 2.4762 3.750 3.717 2.500 2.481 1 3/4 1.750 0.110 1.245 2 3/4 2.7500 2.7262 4.125 4.090 2.750 2.730 2 2.000 0.120 1.370

3 3.0000 2.9762 4.500 4.464 3.000 2.979 2 1/4 2.250 0.130 1.495 3 1/4 3.2500 3.3362 4.875 4.837 3.250 3.228 2 1/4 2.250 0.140 1.620 3 1/2 3.5000 3.4762 5.250 5.211 3.500 3.478 2 3/4 2.750 0.150 1.745 3 3/4 3.7500 3.7262 5.625 5.584 3.750 3.727 2 3/4 2.750 0.160 1.870

4 4.0000 3.9762 6.000 5.958 4.000 3.976 3 3.000 0.170 1.995

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Tolerance Notation There are several ways to show allowable ranges of numbers: limits, bilateral, symmetric bilateral, and unilateral for holes and shafts. The tolerance of the number is the difference between the maximum allowed value and the minimum allowed value. Sometimes the this term is also used to describe the plus and minus values, but technically it should be used for the full range. Limits show the maximum and minimum values a number may have; . In current practice, one always places the larger value on top. The tolerance of this number is .0014.

2.53482.5362

Bilateral uses upper and lower uncertainties which are different; 3.756−.005

+.008 . The signs must always be included and be opposite signs. You should never leave a value with two positive signs or two negative signs. The tolerance of this number is .013. Symmetric or symmetric bilateral has the upper and lower uncertainties the same, so they are combined with a ± sign as in 4.025 ± .012. If the upper and lower values are the same you should always use the symmetric notation. This is the preferred form for general uncertainties. The tolerance of this number is .024. Unilateral comes in two forms, but in each of them one of the values is 0. For unilateral hole the minus value is zero. This is done because if the hole is too small it may always be made larger, so the value gives the overshoot. .2378−0

+.0007 is an example. The tolerance is .0007. Note that the –0 value must be included. For unilateral shaft it is just the reverse. If the shaft is too large it may always be made smaller so the undershot is given. .2345−.0004

+0 is an example with a tolerance of .0004. The +0 values must also be given. A number may be converted from one for to another, however the tolerance should always be the same for each. The one exception is for symmetric if the tolerance is odd. In that case make the tolerance the next larger even number and proceed. This is to avoid increasing the number of significant digits. All the values should also yield the same maximum and minimum value. For example given the bilateral number .4876−.0003

+.0009 convert it to limits, hole unilateral, shaft unilateral and symmetric. The tolerance is .0012. For the limits add the upper and lower values to the bilateral nominal value .4876. For hole unilateral take the minimum value from the limits and use the tolerance as the + value. For shaft unilateral take the maximum value from the limits and use the tolerance as the - value. For symmetric take the average of the limits and use half the tolerance as the ± value. Bilateral Limits .4873

.4885 .4876−.0003+.0009

Hole unilateral Shaft unilateral .4885.4873−0

+.0012−.0012+0

Symmetric .4879 ± .0006

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To Calculate RC Fits Using the Tables.

Hole Priority Take a nominal size of .3475 to determine an RC3 fit using hole priority. The table gives:

Nominal Size Clearance Hole Shaft 0.24-0.40 0.5

1.5 +0.6

0 -0.5 -0.9

The values in the tables are in thousandths of an inch so you have to adjust the figures. When calculating for a hole priority the values in the table may be used as they are. The dimensions are: .3475 0

+ for the hole and .3475 for the shaft. This is an improper form and must be changed to the correct unilateral form hence the shaft becomes, by subtracting .0005 from the nominal values and adding .0005 to the tolerances, .3470

.0006−.0009−.0005

−.0004+0 . Then the dimensions appearing the drawing are

Hole .3475 : Shaft .3470 (The hole has the nominal size and is larger than the shaft.) 0

+.0006−.0004+0

Shaft Priority.

Take a nominal size of .5280 to determine an RC3 fit using shaft priority. The table gives:

Nominal Size Clearance Hole Shaft 0.40 – 0.71 0.6

1.7 +0.7

0 -0.6 -1.0

The values in the tables are in thousandths of an inch so you have to adjust the figures. For a shaft priority we have to work backwards. First get the tolerance of the shaft by finding the difference between the two shaft values - .0004 in this case (1.0 – 0.6 adjusted to inches). So we begin by stating the shaft with its tolerances and changing it to limits. Shaft = .5280 − = .0004

+0.5276.5280

For an RC fit (clearance) the hole is larger than the shaft so we use the clearance values to find the hole limits. The smallest hole is .0006 larger than the largest shaft and the largest hole is .0017 larger than the smallest shaft. .5276+.0017.5280+.0006 = gives the hole limits. Converting this to unilateral values for a hole gives the drawing dimensions:

.5293

.5286

Hole .5286 : Shaft .5280 (The shaft has the nominal size and is smaller than the hole.) 0

+.0007−.0004+0

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To Calculate FN Fits Using the Tables.

Hole Priority Take a nominal size of .4235 to determine an FN4 fit using hole priority. The table gives:

Nominal Size Interference Hole Shaft 0.40 – 0.56 0.7

1.8 +0.7

0 +1.8 +1.4

The values in the tables are in thousandths of an inch so you have to adjust the figures. In calculating for a hole priority the values in the table may be used as they are. Thus the dimensions are: .4235 0

+ for the hole and .4235 for the shaft. This is an improper form and must be changed to the correct unilateral form hence the shaft becomes, after adding .0018 to the nominal values and subtracting .0018 from the tolerances, .4253

.0007+.0014+.0018

−.0004+0 . Then the dimensions appearing in the drawing

are Hole .4235 : Shaft .4253 (The hole has the nominal size and is smaller than the shaft.) 0

+.0007−.0004+0

Shaft Priority

Take a nominal size of .8164 to determine an FN4 fit using shaft priority. The table gives:

Nominal Size Interference Hole Shaft 0.71 – 0.95 0.8

2.1 +0.8

0 +2.3 +1.8

The values in the tables are in thousandths of an inch so you have to adjust the figures. For a shaft priority we have to work backwards. First get the tolerance of the shaft by finding the difference between the two shaft values .0005 in this case (2.3 – 1.8 adjusted to inches). So we begin by stating the shaft with its tolerances and changing it to limits. Shaft = .8164 − = . .0005

+08159

.8164

For an FN fit (interference) the shaft is larger than the hole so we use the interference values to find the hole limits. The largest hole is .0008 smaller than the smallest shaft and the smallest hole is .0021 smaller than the largest shaft.

0021.8164.0008.8159.

−− = gives the hole limits. Converting this to unilateral values for a hole gives the

drawing dimensions: ..8151.8143

Hole .8143 : Shaft .8164 (The shaft has the nominal size and is larger than the hole.) 0

+.0008−.0005+0

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Welding Symbols

.25 1 - 3

.50 2 - 4

1

23

3 4

45

5

.25 1 - 3

.50 2 - 4

1

23

3 4

45

5

A typical corner joint. Note that the arrow can go in either direction, but the left to right ordering of the symbols does not change. The arrow points to the joint to be welded. 1. Fillet weld on the same side as the arrow. 2. Bevel weld on the opposite side from the arrow. 3. Depth of the weld. 4. Length of the weld. If this is omitted the entire length is assumed. 5. Pitch of the weld. This is the center to center distance between the welds. This value must be greater than the length of the weld. The distance between the welds (distance of no weld) is the pitch minus the length. If the pitch is omitted, a single weld is assumed.

.125

3 6

7 8

A butt joint. Repeated balloons have the same definition as above. 6. A V weld. 7. The circle at the joint means the weld goes all the way around the joint. 8. The flag at the joint means that the weld is to be done in the field, rather than in the shop.

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.25 1 - 2 .25 1 - 2

.25 1 - 2 .25 1 - 2

The placement of the symbols will tell the orientation of the welds. On the left the symbols are directly opposite each other so the welds will be that way also. In the right drawing the symbols are staggered, thus the welds will be also. On weld will start right at the end of the joint while the one on the opposite side will start 1 inch in from the end.

Fillet Square Bevel V Plug / Slot J U The common types of welds encountered and their corresponding symbols. The symbols above the line represent welds opposite the arrow. The symbols below the line represent welds on the same side of the joint as the arrow. The fillet symbol, bevel symbol, and J symbol always have the vertical line on the left side irregardless of how the arrow is pointing.

Corner T Butt Lap Edge

The types of joints encountered. The corner and T can have Fillet, V, bevel, square, J and U welds. The butt joint has the square, V, bevel, J and U welds. The lap joint usually has a plug or slot weld. The edge joint is for angles 0 – 30° and can be welded as a corner. The thickness of the material helps determine the type of weld. The square weld is used for thin joints while the bevel, V, J and U are used for thick pieces. The fillet is an external weld as it extends outside the joint, while the others are internal welds which can leave a flush surface. Combinations may be used by stacking the symbols, such as a bevel followed by a fillet for finished appearances.

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Homework Hints – ME152 Sheets 1, 2, 3: The purpose of these is to properly measure and add dimensions to the drawings. You have to utilize the rules discussed in lecture an in the text in chapter 10. Neatness is very important. All lettering must be done in block upper case letters as done in ME151. This applies to all homework sheets! Plan ahead on where you should place the dimensions for maximum clarity and to avoid cramping the dimensions together. do a freehand sketch for planning purposes. ANSI standards are used throughout. On sheets 2 and 3 the proper callouts for the counterbore holes must be used. There are several correct ways to add dimensions, so you have some choices to make. Sheet 4: This sheet is to work with tolerances and in determining the type of fit. For the RC and FN fits use figures 10-116 and 10-120 in the text to obtain the values. The tables are for hole priorities. To get shaft priorities use the method given in section 2 of the lab manual. Sheet 5: The purpose is to dimension a drawing when tolerances are involved. A default tolerance should be placed in a note, while one shot tolerances (the RC and FN) are placed in the dimensions. Use appropriate decimal places throughout. Sheet 6: The purpose of this sheet is to dimension a drawing when GDT’s are included. Plan ahead as to where everything should be placed. A free hand sketch for planning purposes is a big help. The style used in this course is that all GDT’s and datums must be placed on the body, not on extension lines. (See Style Sheet in Lab Manual.) Bent leaders are to be used with the control boxes and placed on the appropriate edge. Sheet 7: The purpose of the first half is to get practice drawing the GDT symbols. To determine the number of datums each needs look at the lecture overheads. The second half is for reinforcing the vocabulary of tolerancing. If in doubt look in the text in chapter 10 for clarifying some of the definitions. Sheet 8: This is an exercise in using tables for threaded fasteners, as well as reinforcing the vocabulary of fasteners and in interpreting the callouts of the fasteners. You will have to find the correct tables, either in the lab manual of in the back of the text. As engineers you will be expected to determine appropriate tables to use as well as to read them correctly.

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An Example: Given: Hex Head Machine Screw 1/2 – 13 UNC 2A x 3 Table: Internal or External: External (A in callout) RH of LH threads RH (No note in callout) Single or multiple Single (No note in callout) Pitch of thread 1/13 inch Threads per inch 13 Lead of thread 1/13 inch (Defined in Lab Manual) Major diameter .500 inch Minor diameter .400 inch (Calculated using formula in lab manual) Class of fit 2 (Average) Head diameter 3/4 inch (look up in table – use maximum value) Head height 11/32 inch (look up in table – use maximum value) Sheet 9: This is an exercise in determining callouts for screw holes given the screw as well as in drawing through holes and threaded holes. Again you will have to use several different tables to gather the proper information. The callouts go in the boxes above and below the two plates. Examples: Oval Head Screw #10 – 24 UNC 2A x 1.00 (Look up the TPI in a table.) n .22 w n .385 x 82° (the through hole is .03 bigger than the major diameter. The head size must be looked up in a table.) Thru hole in bottom plate: #10 – 24 UNC 2B (no depth since it is a through hole.) Fillister head machine screw 1/4 – 20 UNC 2A x .75 (Look up the TPI in a table.) n .28 v n .375 x .172 (the through hole is .03 bigger than the major diameter. The head size must be looked up in a table.) Blind hole in bottom plate 1/4 – 20 UNC 2B x .422 (the depth is determined by taking the length less the upper plate thickness plus the height of the head.) When drawing in the holes make sure that you complete the hatching. (An example was given in lecture and there is an example in the Lab Manual.) Sheet 10: This is to have you generate a table of minor diameters for various threads. This table will be needed for later exercises where the threads needed will be determined by the minor diameter of the screw. Use an Excel spread sheet to do this so that you do not have to due repetitive hand calculations. Sheet 11: The purpose of this exercise is to do an easy calculation to determine a size and then do a design layout of a simple bottle and cap. This is not a test to see how fancy a bottle you can do. Keep it simple. The only dimensions needed are the diameter, height and thread callouts of the cap. No others should be included. A design layout is the

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feasibility design so all the other dimensions will be fleshed out next week as you do the detail drawings. Even though this is a design layout, you should still use your drawing tools and draw the bottle and cap to scale. A single view is all that is necessary. Sheets 12, 13 and 14: For sheets 12 and 13 you will do the detail drawing of the cap and bottle. Multiple views and section views will be required to fully dimension the drawing. On sheet 14 a front view of the bottle and cap will be used to give an assembly drawing. Balloons with bent leaders will be used and a bill of materials needs to be included. Use a 4 digit number (no letters) for the drawing numbers and assembly numbers and properly use them in the title block and BOM. Sheet 15: This is the design layout for the project. You will have to do several calculations to determine the proper screw to use as well as the FN and RC fits. These must be included. Again as this is a design layout, only include the major dimensions – those given in the project and those calculated. Do not try to include other dimensions since if the calculations are wrong you will have to change those values later on. Basically all you need are the overall size dimensions, the screw thread call out, and the sliders and hole diameters with the proper fit calculated and included in layout. Sheet 16: This is pretty self explanatory. You are to place the proper weld symbols and values in the leader lines following the description below each diagram. For the third one you will have to determine the depth of the welds and include them in the callout. Sheet 17: This sheet was described in lecture. The purpose is for you to determine where welds are needed and place them in. The only coordinate dimensions needed are the length of the ramp and its height. For your design, ask yourself if you would like to drive your car over the ramp at 35 mph. You also do not want a car to hang up on the ramp so think about the wheel base and bottom clearance of a car in considering you dimensions.

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