2. Description of Project and Procedure
Computer Aided Design (CAD) is one of the key components in the creation of a
product. A product life cycle goes through two main phases, one of which would be the design
process, and the other, the manufacturing process. During the design phase of a product, the
use of CAD software aids in both synthesizing and analyzing an entire assembly, as well as
each individual component created throughout the process. Applications of CAD software can
also determine the properties of a component such as its mass, material, stress at a given point,
and dimensions to name a few. CAD can be broken up into 3 main disciplines: geometric
modeling, computer graphics, and design applications, all of which can provide an in depth
analysis of the product’s unique properties in different forms. Drafting can be performed in both
2-Dimensional and 3-Dimensional Solid Model settings, where programs such as AutoCAD
produce 2-D models, and programs such as Solidworks are able to produce the latter. CAD
software is designed to run on the Unix, Linux, Windows, and Macintosh operating systems
(OS). Important to note that before any designing is carried out, a theoretical background in
engineering principles such as physics, chemistry, and mathematics is required in order to
validate and verify a design, and users should be able to understand the concepts of geometric
modeling and the software’s functions. Over the course of developing CAD skills, the user will
be able to identify and find commands in order to produce a part or assembly in the most
efficient and error-free manner, as well as gain the ability to analyze 3-D models with greater
ease.
The final project for ME430-101 involved designing a swing table assembly. Using
Solidworks 2016-2017 software, each individual part of the assembly could be created
separately, and would finally assemble together to form the final product. The parts created in
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3. this assembly include: the base, trunnion stud, table, 2 hex bolts, 2 hex nuts, 2 washers, and 1
oval point slotted set screw, totalling out to 10 individual parts altogether. Important to note is
that the IPS unit system was used to carry out this project.
To begin the assembly, the base component was created first. Using the top plane as
reference, the initial extrusion was made in order to produce the foundational 7”x7” section that
held up the rest of the part. Next, two semi-circular sections of the base feature were cut
through the surface, where the Infinite Centerline, Circular Arc, and Line tools were used to
create this cut section. Next, extrusions for both sidewalls were made of ½” thickness, followed
by creating one datum plane at the midpoint of one sidewall. Using the reference datum plane,
an extrusion for the core section’s thickness was made, extruded mid-plane, and could then be
mirrored across the right datum plane using the Mirror tool. In order to create the ¾” width core
slots, an Extruded Cut was made on the surface of the protruding sidewall, where the 3 Point
Arc tool was selected to produce the desired radius, and the Offset Entities tool could produce
the correct width of the core slot. Several more holes were made at the sidewall, were either the
Hole Wizard tool or a simple extruded cut could be made to fulfill the given dimensions of the
holes. Finally, ⅛” rounds were made at the necessary edges of the part, as well as a ½” round
was created at the 3.5” protrusion along the center of the foundation part.
The next component of the assembly was the table. Similar to the previous part made,
the initial 7”x7” square extrusion was made first to create the base feature. This was followed by
producing the square patterned sections at the top of the base feature. Given the dimensions in
the engineering drawing, I found it easiest to produce those sketches on a datum plane
referenced at one side surface of the base feature, and extrude them Through All of the part. An
extruded cut was then made at the section perpendicular to the previous extrusion, and was
dimensioned accordingly to create the proper cut that ran through the entirety of the side of the
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4. initial extrusion. After further analyzing my own steps in creating that section, it could have been
much easier to produce ¼ of the top section, and pattern it about a vertical and horizontal
centerline. To continue, the bottom portion of the table was completed by creating a reference
plane 4.5” from the center of the part, and extruding the sketched section Mid-Plane in order to
get a symmetric distance from the plane at both sides. The tools involved in creating this section
include the 3 Point Arc, Center Circle, Mirror Entities, and setting the correct tangent edge
constraints to prevent any extruding errors. Once finished, more extrusions were added onto the
surfaces of these sections made, and circular cuts were made at their specified heights to form
the slot features to which the bolts and studs could fit into. A single hole at the bottom of one of
the table arms was also made to provide room for the slotted set screw. And similar to the base
part, the necessary rounds were made at the end of the build.
Next, the trunnion stud was produced in a manner which could follow the lengths
described in the drawing. First, a set of parallel reference planes were distanced to the specified
lengths from each other. Following, center circles were sketched on each reference plane with
the desired diameters, and were then extruded to the next surface made, starting from the
center of the part and outwards. Another way to produce this part could also have been to use
the Revolve feature, where the cross-sections for each of the parts could be sketched, and
eventually revolved about a horizontal centerline. And finally, a small circular cut section was
made for the slotted set screw using the Hole Wizard tool.
Once the three components are made, a new Swing Table Assembly could be made,
where the base would be placed as the default constraint. Next, the trunnion stud could be
assembled and mated with its corresponding slots in the base using the concentric and
coincident constraints to place the component properly. Afterwards, the table part was brought
into the assembly, and was constrained and coincided with the trunnion stud, where the holes of
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5. the table were to match with the diameters of the specified sections of the trunnion stud. With
these components constrained, the assembly is able to rotate freely about the stud’s axis. Next,
the hex bolts, hex nuts, washers, and slotted set screw were all accessed through the
Solidworks Toolbox Library Add-In. Using the Tool Library, the correct diameter of each
component could be given as well as any cosmetic threads could be made as well, and
assembled into the swing table. The lengths of the hex nuts could be adjusted simply by clicking
the end surface and dragging it to the appropriate distance. By selecting each component in the
Tool Library, Solidworks provided the available sizing options and types for each part, where
wide versions and other shaped versions could also be chosen for each part. Once each of the
components were added into the graphics area, they were mated to their corresponding parts
and surfaces, which would then complete the entire swing table assembly.
Once finished with the assembly, material assignments were given to each component in
order to be viewed in the Bill of Materials of the detailed drawings. The individual parts were
also colored to their own unique appearance using the Edit Appearance toolbar. Next, an
interference check was made in the Evaluate tab, where two interferences were detected at the
outer surface of the hex bolt and inner surface of the mating table hole. This is due to the
threaded section created in the bolt, and can be disregarded as an interference, as no given
measurements were made for those sections. An exploded view was created for the entire
assembly, which was then saved and used as the view for the detailed drawing portion of the
project.
Following the creation of the Swing Table Assembly, detailed drawings were given for
the entire assembly, base, trunnion stud, and table. For the assembly drawing, a bill of materials
was created for each component of the assembly, and the view was set as exploded in order to
make all individual parts visible. Each material and quantity could be indicated in the bill of
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6. materials with a matching circular split line balloon attached to each component. The detailed
drawings for the base, table, and trunnion stud followed a similar format, where a front, top,
right, and right sectional side view were created for each part, as well as a trimetric view at the
top right corner. Dimensions were created for each part by carefully following the basic
dimensioning guidelines, some of which included placing dimensions between sharing views,
dimensioning only on solid lines (not hidden lines), and deleting any repetitive dimensions to
name a few. The overall goal of a detailed drawing is so that the machinist is able to read and
machine the product with greater ease and less error, and by following the dimensioning
guidelines, a successful product can be manufactured.
Once all of the steps in the procedure were carried out, the Swing Table Assembly and
Detailed Drawings were considered complete.
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