TECHNICAL GRAPHICS (T.G.)
JUNIOR CERTIFICATE EXAMINATION
REVISION NOTES 2017
MR. J. LYSTER
PATRICIAN SECONDARY SCHOOL NEWBRIDGE, CO. KILDARE, REP. OF IRELAND.
MAILTO: josephlyster@patriciansecondary.com
JOSEPH LYSTER 2017 ©
EXCELLENCE IN TECHNICAL GRAPHICS
• A. EXAM GUIDANCE [GENERAL]
1. FORMAT
2. TIMING
3. SUGGESTED APPROACH
• B. SHORT QUESTIONS
1. 2013 – 2016
• C. LONG QUESTION: LEARNING AREAS
1. FIRST PRINCIPLES (MULTIPLE AREAS)
2. ORTHOGRAPHIC PROJECTION WITH AUXILIARY
3. ROTATION OF OBJECTS
4. AXONOMETRIC PROJECTION
5. ISOMETRIC SCALE
6. DEVELOPMENT OF SURFACES / SOLIDS IN CONTACT
7. TRANSFORMATION GEOMETRY
8. ELLIPSE & PARABOLA
9. CIRCLES IN CONTACT
• *NOT ALL SHORT QUESTION AREAS ARE COVERED IN THESE NOTES SO REFER TO EXAMPLES AS DONE IN
CLASS AND IN EXAM PAPERS I.E. SKETCHING, TERMINOLOGY, C.A.D. COMMANDS, BAR/PIE/LINE
CHARTS/GRAPHS ETC…
CONTENTS
EXAM GUIDANCE
FORMAT
EXAM GUIDANCE
• FORMAT:
 EXAM DURATION
 HIGHER LEVEL = 3 HOURS
 ORDINARY LEVEL = 2.5 HOURS
 EXAM PAPER STRUCTURE
 TWO SECTIONS IN EXAM PAPER
 SECTION A = MIXED TOPIC SHORT QUESTIONS
 FIFTEEN SHORT QUESTIONS (ANSWER ANY TEN – TRY ALL)
 SECTION B = LONG QUESTIONS
 SIX LONG QUESTIONS (ANSWER ANY FOUR) SEE TABLE BELOW
TG PAPER SECTION B: LONG QUESTIONS
QUESTION HIGHER LEVEL ORDINARY LEVEL
1 ORTHOGRAPHIC PROJECTION ORTHOGRAPHIC PROJECTION
2 ROTATION OF OBJECTS ELLIPSE
3 AXONOMETRIC/ ISOMETRIC SCALED DEVELOPMENTS
4 SOLIDS IN CONTACT & DEVELOPMENTS OBLIQUE & ISOMETRIC GRID DRAWING
5 TRANSFORMATION GEOMETRY TRANSFORMATION GEOMETRY
6 ELLIPSE, PARABOLA & CIRCLES IN CONTACT CIRCLES IN CONTACT
EXAM GUIDANCE
• TIMING:
 HIGHER LEVEL
 3 HOURS (180 MINUTES)
 SPEND 3 TO 5 MINUTES PREVIEWING EXAM PAPER AT START
 SECTION A: RECOMMENDED TIME = 45 MINUTES MAX [35 MINUTES OR LESS WOULD BE
IDEAL]
 SECTION B: RECOMMENDED TIME = 130 MINUTES MAX (32.5 TO 35 MIN/QUESTION)
 KEY TIP: WHEN STUDYING, GET INTO THE HABIT OF DOING QUESTIONS RELATIVE TO THE
TIMING SUGGESTED. WHEN IN THE EXAM, HAVE TIME QUES OR BE VIGILANT OF TIME
DURING THE EXAM TO REMIND YOU TO PROGRESS FROM ONE QUESTION TO ANOTHER.
 ORDINARY LEVEL
 2.5 HOURS (150 MINUTES)
 SPEND 3 TO 5 MINUTES PREVIEWING EXAM PAPER AT START
 SECTION A: RECOMMENDED TIME = 25 TO 30 MINUTES MAX
 SECTION B: RECOMMENDED TIME = 120 MINUTES MAX (30 MIN/QUESTION)
 KEY TIP: WHEN STUDYING, GET INTO THE HABIT OF DOING QUESTIONS RELATIVE TO THE
TIMING SUGGESTED. WHEN IN THE EXAM, HAVE TIME QUES OR BE VIGILANT OF TIME
DURING THE EXAM TO REMIND YOU TO PROGRESS FROM ONE QUESTION TO ANOTHER.
EXAM GUIDANCE
• SUGGESTED APPROACH: BE ‘SMART’…
 DON’T PANIC, EASY FOR ME TO SAY BUT REALLY DON’T PANIC. THE EXAM PAPER WILL
LOOK DIFFERENT BECAUSE ALL OF THE QUESTIONS ARE NEW AND PREVIOUSLY UNSEEN.
TAKE A MINUTE TO RELAX AND THEN CONFIRM TO YOURSELF THAT YOU ARE REFINED IN
THE METHODS /UNDERSTANDING TO ANSWERING SUCH QUESTIONS. REMEMBER THAT
YEAR ON YEAR THE FACE OF THE QUESTIONS MAY CHANGE BUT THE DETAIL IS THE SAME,
THE METHODS ARE CONSISTENT AND THERE IS A LOGICAL SEQUENCE TO BE FOLLOWED IN
ALL CASES.
 UPON REVIEW OF EXAM PAPER, MARK THE QUESTIONS YOU FEEL MOST CONFIDENT
ABOUT DOING
 DO SECTION ‘A’ FIRST AND BEGIN WITH WHATEVER QUESTION YOU FEEL YOU CAN
ANSWER BEST. MAKE SURE YOU HAVE ATTEMPTED AT LEAST 10 SHORT QUESTIONS
THOUGH I DO RECOMMEND THAT YOU DO ALL FIFTEEN IF POSSIBLE.
 MOVE ONTO SECTION ‘B’ AND AGAIN BEGIN WITH YOUR STRONGEST QUESTION, I.E. THE
ONE YOU KNOW YOU CAN DO BEST IN THE LEAST AMOUNT OF TIME!
 BE MINDFUL OF TIME…AS PREVIOUSLY MENTIONED.
 IN ALL CASES, REMEMBER TO DOUBLE CHECK WHAT THE QUESTION IS ASKING YOU. IT IS
NOT UNCOMMON TO PRESUME SOMETHING OR OVERLOOK SOMETHING. BE DILLIGENT
HERE.
 IF ALL ELSE FAILS JUST HAVE A GO. IT CAN DO NO HARM TO HAVE A GO.
 IF YOU HAVE TIME AT THE END, SPEND IT BY REVIEWING THE WORK YOU HAVE DONE OR
TIDYING UP/FINISHING INCOMPLETE QUESTIONS
 DO NOT LEAVE THE EXAM HALL WITHOUT HAVING ATTEMPTED THE REQUIRED
AMOUNT OF QUESTIONS TO THE BEST OF YOUR ABILITY.
EXAM GUIDANCE
MAKE SURE YOU HAVE ALL OF THE
REQUIRED DRAWING EQUIPMENT
WITH YOU FOR THE EXAM!!!
CHECKLIST
 5H/2H/HB PENCILS
 PENCIL PAIRER & RUBBER
 MASKING TAPE/PAGE CLIPS
 CALCULATOR (IF NEEDED)
 BOW COMPASS (BRING SPARE COMPASS LED AND SAND PAPER)
 45° AND 60° SET-SQUARES (ADJUSTABLE SET-SQUARE TOO IF DESIRED)
 PROTRACTOR AND CIRCLE TEMPLATE
 T-SQUARE
SHORT QUESTIONS
MIXED TOPICS
SHORT QUESTIONS 2013
SHORT QUESTIONS 2014
SHORT QUESTIONS 2015
SHORT QUESTIONS 2016
LEARNING AREAS
LONG QUESTIONS
OVERVIEW
FIRST PRINCIPLES
FIRST PRINCIPLES
FIRST PRINCIPLES
FIRST PRINCIPLES
FIRST PRINCIPLES
PENTAGON
[360/5 = 72°]
HEXAGON
[360/6 =
60°]
PENTAGON – 5 SIDED [ANGLE 360°/5 = 72°]
HEXAGON – 6 SIDED [ANGLE 360°/6 = 60°] OCTAGON – 8 SIDED [ANGLE 360°/8 = 45°]
60º 45º
FIRST PRINCIPLES
BISECTING A LINE
[STEPS]
FIRST PRINCIPLES
BISECTING AN ANGLE
[STEPS]
FIRST PRINCIPLES
3
DIVIDING A LINE INTO AN EQUAL NUMBER OF PARTS
https://www.youtube.com/watch?v=X_d61-dz9nY
1
2
3
A B
A B
A B
1
2
A B
3
1
2
A B
3
1
2
A B
1.
2.
6.
3.
5.
4.
FIRST PRINCIPLES
AREAS, ENLARGEMENT & REDUCTION
AREAS, ENLARGEMENT & REDUCTION
Enlarge from ‘O’ to ‘A1’
Reduce irregular pentagon to
scale of 2:3
Enlarge to 125mm length
Inscribe square of maximum
size into given triangle
AREAS, ENLARGEMENT & REDUCTION
OVERVIEW
ORTHOGRAPHIC PROJECTION
ORTHOGRAPHIC PROJECTION
END VIEW
PLAN
ELEVATION
ORTHOGRAPHIC PROJECTION
ORTHOGRAPHIC PROJECTION
ORTHOGRAPHIC PROJECTION
ORTHOGRAPHIC PROJECTION
STANDARD AUXILIARY PROJECTION
AUXILIARY ELEVATION
AUXILIARY PLAN
AUXILIARY ELEVATION:
PROJECT FROM PLAN AND TAKE
MEASUREMENTS FROM
ELEVATION
AUXILIARY PLAN:
PROJECT FROM ELEVATION AND
TAKE MEASUREMENTS FROM
PLAN
STANDARD AUXILIARY PROJECTION
STANDARD AUXILIARY PROJECTION
OVERVIEW
ROTATION OF OBJECTS
ROTATION OF OBJECTS
ROTATION OF OBJECTS
ROTATION OF OBJECTS
ROTATION OF OBJECTS
ROTATION OF OBJECTS
ROTATION OF OBJECTS
ROTATION OF OBJECTS
ROTATION OF OBJECTS
ROTATION OF OBJECTS
OVERVIEW
AXONOMETRIC PROJECTION
AXONOMETRIC PROJECTION
TYPE 1: ISOMETRIC
AXONOMETRIC PLANE IS AN EQUILATERAL
TRIANGLE
IN QUESTION ASSUME AS NORMAL
AXONOMETRIC PROJECTION
ISOMETRIC
AXONOMETRIC PROJECTION
ISOMETRIC
AXONOMETRIC PROJECTION
ISOMETRIC
AXONOMETRIC PROJECTION
ISOMETRIC
AXONOMETRIC PROJECTION
ISOMETRIC
OVERVIEW
SCALED ISOMETRIC
SCALED ISOMETRIC
ISOMETRIC
SCALED ISOMETRIC
ISOMETRIC
OVERVIEW
DEVELOPMENTS & SOLIDS IN CONTACT
(S.I.C.)
DEVELOPMENT & S.I.C.
DEVELOPMENT & S.I.C.
DEVELOPMENT & S.I.C.
DEVELOPMENT & S.I.C.
DEVELOPMENT & S.I.C.
DEVELOPMENT & S.I.C.
OVERVIEW
TRANSFORMATION GEOMETRY
TRANSFORMATION GEOMETRY
TRANSFORMATION GEOMETRY
RECOMMENDED STEPS:
1. READ THE QUESTION
2. POSITION START POINT IN TOP-LEFT AREA OF PAGE
3. DRAW THE FIGURE AND MAP OUT ALL POINTS,
NAMELY P, P1, P2, P3, P4, AS DIRECTED.
4. FOLLOW THE INSTRUCTION FOR THE ORDER OF
TRANSFORMATIONS AS OUTLINED IN THE QUESTION
1. P – P1 = AXIAL
2. P1 – P2 = CENTRAL
3. P2 – P3 = TRANSLATION
4. P3 – P4 = ROTATION CLOCKWISE 90°
OVERVIEW
ELLIPSE AND PARABOLA
ELLIPSE AND PARABOLA
ELLIPSE BY CONCENTRIC CIRCLES METHOD
PARABOLA BY RECTANGLE METHOD
ELLIPSE
BY
CONCENTRIC CIRCLES
PARABOLA
BY
RECTANGLE METHOD
ELLIPSE AND PARABOLA
ELLIPSE AND PARABOLA
ELLIPSE CONSTRUCTION
OMITTED
ELLIPSE AND PARABOLA
ELLIPSE CONSTRUCTION
OMITTED
ELLIPSE AND PARABOLA
ELLIPSE CONSTRUCTION
OMITTED
ELLIPSE AND PARABOLA
ELLIPSE AND PARABOLA
OVERVIEW
CIRCLES IN CONTACT
CIRCLES IN CONTACT
CIRCLES IN CONTACT
CIRCLES IN CONTACT
CIRCLES IN CONTACT
CIRCLES IN CONTACT

JUNIOR CERTIFICATE: TECHNICAL GRAPHICS NOTES