1. The document outlines the objectives and materials to be covered in a class on engineering drawings and measurements, including how to use a Vernier caliper and read different types of drawings. 2. Students will learn how to accurately measure dimensions with a Vernier caliper, including understanding its two scales and multi-step measurement process. 3. The main types of drawings covered are isometric, exploded, and orthographic views, along with features like hidden lines, center marks, and section views. 4. In class, students will work in groups to create orthographic drawings of a provided object using Vernier calipers, with the opportunity for extra credit if an isometric view is also included.

1. Prof. Justen Garner
CLT: Mr. Mohammed
New York City College of Technology
Date: 09-16-2019

2. Objectives:
 Review on how to take measurements with
a Vernier Caliper.
 Material covered: Section C Unit 3
 A detailed explanation on how to read
drawings
 Material covered: Section A Unit 3
○ Types of drawings
 Types of views
○ Types of holes
○ Tolerances
 Classwork Review Project
 Machine Lab

3. Vernier Caliper
 A Vernier Caliper is a
measuring device used
to accurately measure
linear dimensions.
 It can also be used to
measure the diameter of
round objects such as
cylinders. As shown in
Fig. A.
 As you have seen last
week Vernier Calipers
are capable of
measuring outside
dimensions, inside
dimensions, and depth.
As shown in the Fig. B.
Fig. A
Fig. B

4. Vernier Calipers: Scale
 The caliper has two scales which are the main
scale (which can be in millimeters or a tenth of
an inch) and the moving Vernier scale.
 The Vernier scale allows for a more accurate
reading to be taken.
Fig. C

5. How to measure with a Vernier
Caliper in inches?
 In order to read a Vernier Caliper in inches there
are four numbers you need.
 There are three numbers on the major scale and
one number on the Vernier scale.
 The first three numbers will show on the major
scale before the zero on the Vernier scale.
 Steps:
1. Record the number of whole inch reading (1.000)
2. Record the number of major divisions (0.100)
3. Record the number of minor divisions (0.025)
4. Record the number from the Vernier scale of a line that
coincides with a line on the major scale. The divisions
on the Vernier scale a measured 1/100 (0.001)
5. Add all the readings together.

6. Ex. 1

7. Drawings
 In this course we will go over three
major types of drawings.
 Isometric Drawings
 Exploded Drawings
 Orthographic Drawings

8. Isometric Drawing
 An isometric drawing is
a method that visually
represents a three-
dimensional object(s) in
a two dimensional
engineering drawing.
 The lines in the object
remain parallel.
 The isometric axes are
120 degrees apart.
 The blue object in fig. D
is called an Isometric
View.
Fig. D

9. Exploded Drawing
 An exploded drawing is a
technical drawing of an
object (that has multiple
parts), that shows the
order of assembly of
various parts.
 It shows the components
of an object separated by
different distances, or
suspended in space for the
three-dimensional
drawings.
 In most exploded drawings
there will be a “bill of
materials” which shows the
name of the part and the
quantity of that same part.
Fig. E

10. Orthographic Drawing
 An orthographic
drawing contains
three views. These
three views consist
of front, side, and
top views.
 Orthographic
drawings are the
main drawings used
for engineering
design.
Fig. F

11. Hidden Lines and Center Marks
 Features that are not
visible are indicated by
dashed line, these lines
are called hidden lines.
 Hidden lines show the
locations of part
features hidden from
view. They normally are
use to show a hole
feature.
 Center marks are plus
(+) signs that are in the
center of a hole feature.
 The yellow arrows in
Fig. H show some
hidden lines in the part
and a center mark.
Fig. H

12. Section Views
Fig. G

13. Example of a completed Engineering
Drawing (Detailed Drawing)

14. Types of Holes for project 1

15. Tolerances
 Certain dimensions are specified to be within a
certain range, this range is called a tolerance.
 Tolerances normally appear in detailed
drawings.
 Tolerances that have a minimum and
maximum limit are called bilateral tolerances.
 If a dimension does not have a tolerance then
you must use the general tolerance
information shown below:
 2 places .00 tolerance ± .01
 3 places .000 tolerance ± .005
 4 places .0000 tolerance ± .0005

16. Tolerances

17. In Class Project #1
 Break up into 4 groups of 4 or 5 team
mates.
 Each group will receive two vernier
calipers and 1 spinal cage.
 Create orthographic drawing of the
spinal cage. The Isometric view is not
needed.
 If the isometric view is there you have a
chance to receive extra credit.

18. Homework
 Read Sec. A Unit 3 – Complete Self test
on pgs. 35-36
 Read Sec. C Unit 3 – Complete Self test
on pgs. 119-120

19. Grading Policy
 2 Projects – 50%
 Homework – 25% (5 or 6 HWs)
 In Class projects – 10% (2-4)
 Final Exam – 15%