ction
During the Summer of 1996, from May to the end of August we, together with a
number of professors from other Departments within NJIT, met to develop a new
freshman engineering curriculum based on a previously prepared course outline. The
course outline was developed by a committee from more than twelve departments known
as the Fundamentals of Engineering Design/Technology Reinvestment Project
(FED/TRP) committee. This new course, known as Fundamentals of Engineering (FE), is
a follow-up to the existing NSF-sponsored Gateway Coalition Course called
Fundamentals of Engineering Design (FED) which had run for more than three years. In
the FED, students are introduced to three distinct modules in one semester, for example
Mechanical Engineering Module, Chemical Engineering Module, and Civil Engineering
Module. They are always learning two distinct disciplines running parallel during the
semester. FE, on the other hand, is interdisciplinary project based course consisting of
design and computer applications components. The students in FE work as a team on a
number of case-study projects designed in such away that they introduce the freshman
engineering student to a range of the fundamental concepts of engineering. In this
context, the student is exposed to a wide range of engineering disciplines and
applications. The rationale behind this approach is that through multiple exposures to
the fundamental concepts and their integration in different contexts, the student will
develop a strong grasp of the breadth of engineering and provide a road map to their
future studies. The statement in quotes is part of the course proposal statement.
This report describes the Mechanical Engineering component of two of the four projects
that constitute the curriculum for the 1996-97 Fall and Spring semesters, and the rationale
behind the course content.
We begin with the description of course structure, followed by a detailed
description of the two projects
, including the grading and course evaluation schemes
used. 2
Chapter Two
The Course Module
The Mechanical Engineering module of the FE pilot course has two main
components: a fundamentals of engineering component and a computer application or
computer aided design (CAD) component. About 16 to 20 students work on each project
with the authors acting as advisors. For each project, the students are divided into teams
of between 4 and 5 students per team.
2.1 Course Objectives
Before we describe the contents of the two projects, however, we would like to
summarize the main objectives of the course as follows:
to introduce the freshman engineering student to many aspects of engineering as an
entire unit working together, emphasizing the concept of teamwork in engineering
research projects,
to introduce the student to many computer aided design tools available at NJIT which
can be used not only to build models of the product to be manufactured but also for
diagnostic analysis in order to solve potential manufacturing problems,
to introduce the concept of communication among team mates, and
to introduce the concept of technical report writing and oral presentation.
The two projects, Lawn Sprinkler and 3.5 Floppy Disk Drive were chosen because
we believe they have the potential of incorporating all the concepts outlined above. There
are many similarities in the M.E. components of the two projects, nevertheless, each
project will be described in detail 3
2.3 Description of Projects
A. The Lawn Sprinkler Project (FE-101-007)
Figure 1. Nelson Rainshower 40 Lawn Sprinkler
The specific lawn sprinkler chosen for this project is the Nelson Rainshower 40
shown in Fig. 1. The sprinkler is used to sprinkle water on a lawn using dial mechanism.
The dial mechanisms on the sprinkler can be adjusted to oscillate a spray tube according
to the selected pattern of coverage. Thus, the pattern of coverage can be controlled. The
drive mechanism for the sprinkler consists of a turbine connected directly to a system of
spur gears. No extra source of power is needed because the turbine drive mechanism is
driven by water pressure. As the water enters the sprinkler, it goes through a nozzle
directed to the turbine blades, and drives a turbine at high speed at the same time rushing
to the spray tube. The speed of turbine is then reduced by a set of spur gear system that
drives a heart shaped cam at low speed. Then the cam moves the crank slot mechanism
that oscillates the spray tube slowly. More than 90% of this particular lawn sprinkler is
made of plastics, with the only metal component being the spray tube and the screws
holding the various components. Most of the plastic components were injection molded;
the final product was, presumably melt (spin) welded.
The following table - Table 1 shows the various component parts of lawn sprinkler. 4
Table 1.
Example of itemization of lawn sprinkler components.
COMPONENT/PARTS & FUNCTION
PART NUMBER
Aluminum Pipe with perforated holes for sprinkling (spray Tube)
1
Plastic Base (yellow), injection molded
2
Housing for gear system
3
Plastic Turbine (translucent): consist of several parts.
Steel shaft, a plastic gear, a cover for gear box.
4
A plastic gear train consisted of
1) a pair of two gears mounted on disc two sets
2) set of three gears mounted on disc
5
6
A dial mechanism for adjusting the pattern of spray coverage
7
1 turbo heart-shape cam
8
1 crank-slot mechanism linkage
9
2 metal screws
10
1 plug with integral pin to unblock spray holes
11
1 plastic hose connector
12
A nozzle for water flow to turbine
13
1 plastic O ring, possibly EPDM (EPR)
14
1 plastic ring for attaching aluminum pipe to gear housing
15
B. The 3.5 Floppy Disk Drive Project (FE 101-019)
The floppy disk drive has read/write capability, and uses electromagnetism to
"write" or store programs and data. Basically, it is used to transfer information from a
3.5 diskette to the central processing unit (CPU) of a computer and vice versa. The
media located inside of the diskette is coated with a magnetic material that can record
data. The read/write heads, which are tiny electromagnets, use magnetic pulses to change 5
the polarity of metallic particles embedded in the disks coating. The heads convert
electric code signals from the computer into magnetic codes recorded on the surface of
the disk; the drive then reverses this process to "read" the disk. A disk drive contains two
small electric motors - a spindle motor to spin the disk at high speed and a stepper motor
to move the magnetic read/write heads radially across the diskettes surface. When the
computer system needs to access data on the diskette, the read/write heads are stepped by
signals generated by the computer system's floppy controller. The floppy drive has about
eight major components composed of plastics and metals. These include the main frame,
the circuit board, the spin motor, the stepper motor, screw type shaft, read/write heads,
the clamping mechanism, the front panel and door. The chassis, made of die cast
aluminum, is the main frame on which all other components are mounted. A thermoset
plastic (Bakelite) and conductive metals compose most of the circuit board. The screw-
type shaft connected to the stepper motor is made of bronze. The front panel and door are
made of plastic material. A torsion-spring-operated lever opens and shuts the shutter of
diskette enabling data to be accessed.
2.3 Project Objectives
The following is a summary of the Project Objectives:
To understand the mechanism of the team approach (meaning active interaction
between members) to the design and manufacture of products.
To understand the materials used and the mechanisms involved in the function of the
product.
To propose an alternative design of the product.
To prepare a comprehensive Project Report and give an oral Presentation.
(In
the Project Report, the focus is on integrating the various learned methods and
techniques for the purpose of creating a better product.)

In order to achieve these objectives students are expected to carry out the following
tasks:
Disassemble their product, analyze it for design, function and choice of materials. 6
Propose design improvements considering material selection, environmental impact
and the manufacturing processes of the product.
Apply CAD software to draw some of the product components and assemble.
Assess the manufacturability of the part so designed through the use of a computer
aided engineering (CAE) software (Pro/ENGINEER and C-MOLD). This last part of
the project is limited to computer simulation of a mold cavity filling as occurs in
injection molding, for the manufacture of plastic parts.
In order to achieve all these objectives and at the same time insure that the work load was
not too much for these students, we have developed a well structured course syllabus
which also incorporates homework assignments to act as immediate feedback from the
students. There was no formal examination, and the course grade was based on a
combination of homework assignments, bonuses for attendance of seminars by invited
industrialists, oral presentation and the final project report. The latter two form 60% of
the final course grade (see Table 2). The syllabuses for the lawn sprinkler project and the
Floppy Disk Drive project are shown in pages v and vi, respectively.
Mathcad Calculations
In order to ensure that students are able to use MathCad for simple math formulas,
they were introduced to gear types and arrangements as applied to the particular lawn
sprinkler used for the project, and different types of springs and their functions as
these relate to design of a floppy disk drive. In the latter case, not only was the spring
used to exert forces and torques