The RGPV Survivor’s Guide to Unit 1
Engineering Graphics (ED) - The Art of Not Smudging Your Sheet
Your friendly tutor chetan
First Year B.Tech Special Edition
1 Introduction: Why are we doing this?
Welcome to Engineering Graphics. You might be wondering, ”I joined engineering to code AI
or build robots, why am I taping paper to a board?”
The Motivation: Imagine you tell a worker to ”Make a hole there.” They make a square
hole. You wanted a round one. The building collapses. You go to jail. Engineering Graphics is
the language that keeps you out of jail. It is the universal language of engineers. If you can
draw it, you can build it.
Pro Tip: Your Mini-Drafter is not a weapon. Please do not use it to scratch your back or
fight your roommate, no matter how frustrating the subject gets.
2 Topic 1: Scales (The Art of Shrinking Things)
Engineers deal with things as big as dams and as small as microchips. You can’t draw a dam on
A4 paper (unless you have a very, very small dam). Enter Scales.
2.1 Representative Fraction (R.F.)
This is the holy grail number.
Length on Drawing
R.F. =
Actual Length of Object
- Reducing Scale: R.F. < 1 (Drawing a building).
- Enlarging Scale: R.F. > 1 (Drawing a micro-screw).
- Full Scale: R.F. = 1 (Drawing your phone, roughly).
Pro Tip: R.F. stands for Representative Fraction. It does NOT stand for ”Really Frustrating,”
even though calculating it feels like that sometimes.
2.2 Types of Scales (RGPV Favorites)
2.2.1 1. Plain Scale
It measures two units (e.g., Meters and Decimeters). It’s simple, reliable, and boring. Like vanilla
ice cream.
Engineering Graphics (ED) - The Art of Not Smudging Your Sheet
Your friendly tutor chetan
First Year B.Tech Special Edition
1 Introduction: Why are we doing this?
Welcome to Engineering Graphics. You might be wondering, ”I joined engineering to code AI
or build robots, why am I taping paper to a board?”
The Motivation: Imagine you tell a worker to ”Make a hole there.” They make a square
hole. You wanted a round one. The building collapses. You go to jail. Engineering Graphics is
the language that keeps you out of jail. It is the universal language of engineers. If you can
draw it, you can build it.
Pro Tip: Your Mini-Drafter is not a weapon. Please do not use it to scratch your back or
fight your roommate, no matter how frustrating the subject gets.
2 Topic 1: Scales (The Art of Shrinking Things)
Engineers deal with things as big as dams and as small as microchips. You can’t draw a dam on
A4 paper (unless you have a very, very small dam). Enter Scales.
2.1 Representative Fraction (R.F.)
This is the holy grail number.
Length on Drawing
R.F. =
Actual Length of Object
- Reducing Scale: R.F. < 1 (Drawing a building).
- Enlarging Scale: R.F. > 1 (Drawing a micro-screw).
- Full Scale: R.F. = 1 (Drawing your phone, roughly).
Pro Tip: R.F. stands for Representative Fraction. It does NOT stand for ”Really Frustrating,”
even though calculating it feels like that sometimes.
2.2 Types of Scales (RGPV Favorites)
2.2.1 1. Plain Scale
It measures two units (e.g., Meters and Decimeters). It’s simple, reliable, and boring. Like vanilla
ice cream.
