James_Welch_Final_Report_Fall_2014

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ET 493: Senior Design I
Design of Automated Rod Singulation System.
Fall 2014
Advisors: Dr. Saadeh and Dr. Ma
Student: James Welch
I. Abstract
Intralox, a company that designs and manufactures conveyance solutions in the
global market, has chosen Southeastern to aid in the research and design of a new device
that they plan to utilize in their belt manufacturing facilities. The device is referred to as an
automated rod singulation device. Intralox utilizes a variety of extruded polymer rods to
interlock modular plastic shapes when assembling custom conveyor belts. The rods are
pre cut after the extrusion process in lengths up to 150 inches. An automated cutting
machine is then used to cut the rods before they are used to assemble the modular pieces.
This particular cutting machine requires workers to sort about two-dozen rods then
manually load them into a magazine style clip before cutting can begin. In order to reduce
risk of injury and improve efficiency, Intralox requires a device that can sort over 100
extruded rods and distribute them out of the machine one at a time.
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II. Background
The conveyor belts that Intralox manufactures can be used in a wide variety of
applications. By utilizing modular polymer sections, Intralox can manufacture a large
range of belt widths and configurations to meet customer needs. The extruded rods
must be cut in order to interlock the modules to these custom lengths. In Figure 1, the
rods and the modular segments are shown fully assembled.
Rods
Segments
Figure 1: Conveyor Belt Components
The plastic segments are arranged in order and interlocked by the rods, which are inserted by
an employee. To meet customer needs in a timely manner, while maintaining quality
production, an automated cutting machine was developed to cut the rods into customer
specified lengths. This machine requires a trained employee to load a limited number of rods
into a spring loaded staging device. The device has a capacity limitation of about 20 rods at
one time. This typically leads to about a 10 minute run time on average. Due to this
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constraint, employees must be removed from high value tasks in order to keep the machines
operational. In addition to increasing the workload of the employees, the current loading
process presents some safety concerns as well. There are various moving components that
could be hazardous to untrained personnel. Also, the repetitive nature of the loading process
could lead to long-term muscle and joint issues. Figure 2 illustrates the manual loading of
extruded rods for the automated cutting process.
Figure 2: Loading Procedure for Rod Cutting Machine
The actual process of separating the extruded rods, which can become entangled easily,
and loading them to be cut is referred to as the rod singulation process. Intralox wishes
to minimize employee tasks involved in this operation due to scheduling, time
constraints, higher production demands as well as decreasing the chance of human
error and injury.
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III. Objective
Intralox has teamed up with the Southeastern Engineering Technology department
in order to develop an automated rod singulation system. The final system will need to
handle a variety of rod lengths, diameters, and materials. The rod lengths will vary
from 24 to 156 inches. The diameters will be between 0.14 to 0.24 inches. The various
materials will consist of polypropylene, polyethylene, nylon and acetyl. Intralox
requires that a bundle of 100 to 250 rods be loaded into the machine at one time and
mechanically separated then dispersed one by one with little to no human interaction.
Initial research and design of a preliminary system led to the current rod
singlulation device pictured in Figure 3.
Figure 3: 3D Assembly of Prototype Rod Singulation Mechanism
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Through open discussion and abstract design concepts, the following system was
approached as our main singulation solution. Creating individual models of each
component using SolidWorks CAD system developed figure 3. These components were
then mated in an assembly view to form the main singulation device. The white
cylindrical part has a radius groove machined down it along a helix. This design will
allow one rod to occupy each groove of the cylinder. When power is applied to the DC
motor, the rods will be transferred from left to right. The groove radius will allow use
of the device throughout the diameter range specified by Intralox. When a rod reaches
the final groove, a sensor will terminate power to the motor allowing the rod to be
removed. At this point, the singulated rod can be removed by hand as per the
requirements currently requested by Intralox.
IV. Methods
The main objective this semester was to model each component needed to create a
prototype singulation system that can be tested. A 3-D model of each component in the
system was created using Solidworks computer aided design software. Several of these
components need to be manufactured and therefore require technical drawings that
include all information needed to produce the part. The following will explain how this
was done.
The initial system was sketched by hand, my advisors then reviewed the plans and
approved it for modeling. The design would consist of several custom parts that needed
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to be modeled in Solidworks CAD system. The main component of the system is the
white cylindrical piece shown in figure 4. This part will actually separate individual
rods from a bundle.
Figure 4: Helical Separator
As shown in figure 4, the cylinder has several features. The cylindrical surface area has
a radius groove 7cut along a helix. The helix has a pitch of 0.250, or 4 T.P.I. (threads per
inch) and is left handed. The groove has a radius of 1/8 inch, but is only 0.0625 inches
deep, this was done to facilitate the diametric range of the extruded rods. Through the
center of the cylinder is a bore with a keyway. This will allow a shaft to be mounted
with a key to drive the rotation of the separator. To create this part using Solidworks
we begin by drawing a 4 inch circle, Figure 5. Once the diameter is set, the circle can
then be extruded to create the cylinder, as shown in Figure 6. The next step is to create
the geometry for the inside diameter and keyway.
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Figure 5: Creating Diameter of Cylinder
Figure 6: Extruding Circle to Create Cylinder
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This is achieved by creating a sketch on either of the two faces of the cylinder, shown in
Figure 7. Once the geometry is correct we can then select the Extruded Cut command in
Solidworks to “cut” this geometry through the entire cylinder. Figures 7 and 8 show
how this was achieved.
Figure 7: Sketch Geometry on Cylinder Face
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Figure 8: Extruded Cut through Cylinder Body
Next we must create the groove around the face of the cylinder. Start by creating the
geometry of the groove. In this case we needed a radius groove, so I created a ¼ inch
diameter circle positioned at one end of the cylinder. To achieve the depth of 0.0625 for
the groove I placed a point 0.0625 inches away from the cylinder face, Figure 9. Once
the geometry for the groove is created, the helix must be made. The helix gives the path
for the ¼ circle to follow when making the swept cut. Begin by creating a circle at one
end of the cylinder. Make it the same diameter of the cylinder, then select the
Helix/Spiral command. A dialog box will require you to specify the parameters of the
helix, in this case 0.250 pitch with 17 revolutions to assure the cut continues along the
entire part. The completed helix geometry is shown in figure 10. With the geometry
created for the radius cut and the helix, we can now create the cut by choosing the Cut-
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Sweep command. Select the circle geometry for the profile, then select the helix as the
path. This process is shown in Figure 11.
Figure 9: Radius Groove Geometry and Placement
Figure 10: Helix Geometry
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Figure 11: Radius Groove Cut
Finally, the chamfer command is used on the sharp corners of the inside diameter. This
completes the model of the part in figure 4.
Once the 3-D model is complete, Solidworks can reference the part to create a
technical drawing by creating a drawing from a part or assembly. Solidworks then
allows you to select a drawing template. As shown in figure 12, I created a custom
template that I used for each technical drawing needed for this project. Solidworks
offers several ANSI and ISO standard templates, but the template can be modified to
meet any standard or personal preference by modifying the sheet format. Once the
template is selected Solidworks prompts the model view command. This allows the
user to drag and drop multiple orthographic views onto the sheet. For the helical
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separator I used a top view, side view, section view and added an isometric view for
part visualization, figure 13.
Figure 12: Custom Technical Drawing Template
Figure 13: Helical Separator
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As shown in figure 13, the technical drawing should contain all the dimensional
information needed to complete the part. Solidworks makes this task simple by utilizing
the smart dimension tool. With the smart dimension tool active the user can click on
any entity, any radius or diameter, or any two points and Solidworks auto populates the
actual dimension used in the model. The smart dimension command also allows
modification of many other parameters such as tolerances and font. This makes the
conversion from 3-D models to orthographic views much quicker and easier. Also, since
the technical drawing is driven by the model, any design changes made to the 3-D model
are automatically updated in the drawing and assembly files. With all of the necessary
dimensions included, the helical separator technical drawing in figure 13 is ready to be
referenced for production. In this case the design was sent to Laitram Machine Shop for
manufacturing.
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Each component was designed using similar techniques. The following is a list of
figures showing the process used for each part. Since the parts were created in
Solidworks using commands similar to those used to model the helical separator, each
technique will be briefly explained.
-Drive Shaft Adapter
Figure 14: Drive Shaft Adapter
The drive shaft adapter design utilizes several extruded boss and extruded cut
functions. Each journal of the shaft was created independently by adding circular
geometry to dimension and then using the extruded boss command. The keyway on the
middle journal was made by creating a new plane tangent to the top of the shaft. The
key geometry, made to match a standard 3/8 drive key (McMaster-Carr), was drawn on
this plane. That geometry was selected and then cut from that plane down to a user
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specified distance. On the near end the same technique was used to create the inside
diameter bore. This is the bore that will mount the drive shaft adapter to the DC motor.
Figure 15: Drive Shaft Adapter Technical Drawing
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-Motor Mount
Figure 16: Motor Mount
The motor mount was created using extruded boss and extruded cut functions. The
through hole, counter bore, bolt circle and tapped mounting holes were all made using
the extruded cut command. The dimensions for each feature are driven by the
preliminary DC motor that will be used to test the system. Future analysis will be made
to select the appropriate motor based on torque requirements and power consumption.
Once the model was completed the technical drawing is created and finalized for
production. The motor mount here is different than the motor mount in figure 3. Once
the designs were revised it was determined that a much simpler design would be
sufficient. The motor mount in figure 16 will work for our design and be easier and
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cheaper to manufacture, which is very important when creating prototype designs.
Figures 24 and 25 show the assembly with the updated motor mount design.
Figure 17: Motor Mount Technical Drawing
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-End Nut
Figure 18: End Nut
The end nut will be threaded on to the drive shaft adapter to secure the helical
separator and restrict linear motion in the x axis. Simple extrude and cut techniques
were used to create this part. The internal thread is a standard ¾ UNC thread to match
the external threads on the drive shaft. Figure 19 represents the technical drawing sent
to Laitram Machine Shop for manufacturing.
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Figure 19: End Nut Technical Drawing
-Sheet-metal Bracket
Figure 20: Sheet-metal Bracket
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The sheet metal bracket was created using normal cut and extrusion techniques.
Once the design was close to what was desired, Solidworks converted the design to a
sheet metal part. Using the command, convert to sheet metal, Solidworks used a default
bend table to create the radius bends for the user specified sheet metal gauge. Laitram
has their own bend tables, once I acquire them the part will be re-designed. The new
part will be sent to Laitram for manufacturing.
Figure 21: Sheet Metal Bracket Flat Pattern Technical Drawing
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Once each component is modeled in Solidworks the parts can then be used in an
assembly. Solidworks allows the user to make an assembly of modeled parts. Before
this could be done a material list was created. Many components needed to complete
Figure 22: McMaster-Carr Pillow Block Technical Data
the assembly could be purchased instead of designed and produced. The pillow block in
figure 22 is an example of a part needed that was purchased instead of manufactured.
McMaster-Carr, a large hardware supplier, has an online inventory of parts. Each part
has technical data, including 3-D models than can be brought into Solidworks. The
pillow blocks, along with several other components listed in the included material list;
figure 26, were downloaded and used to complete the assembly shown in figures 24 and
25. All hardware was imported from McMaster-Carr into Solidworks.
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Figure 23: Pillow Block Model from McMaster-Carr
Figure 24: Rod Singulator Assembly
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Figure 25: Rod Singulator Assembly with Prototype Wood Frame
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HARDWARE LIST – Intralox Rod Singulation Project – 11/24/14 – James Welch
Website: McMaster Carr
Qty.
Description
Part Number
1 Pack of 50
¼-20 Socket Head Cap Screw 3/8 Length
91251A535
http://www.mcmaster.com/#91251a535/=uqje1z
1 Pack of 50
3/8-16 Flange Nut
http://www.mcmaster.com/#90949a031/=uqjem6
90949A031
1 Pack of 25
3/8-16 Hex Head Cap Screw 1-1/4 Length
http://www.mcmaster.com/#92316a626/=uqjfcc
92316A626
1 Pack of 100
.448 I.D./.760 OD Tooth Lock Washer
http://www.mcmaster.com/#91114a032/=uqjg12
91114A032
1 Pack of 25
¼-20 Set Screw 3/16 Length
http://www.mcmaster.com/#92313a532/=uqjgzq
92313A532
1 Pack of 5
Machine Key 3/8 Square x 1.500 Length
http://www.mcmaster.com/#98870a590/=uqjhtk
98870A590
Figure 26: Hardware needed to complete assembly
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Bill of Materials for Prototype System
Figure 27
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V. Conclusion
The custom components for the singulation device are in production right now. The
technical drawings created were sent to Laitram Machine Shop for manufacturing.
Completed prototype parts are due by mid-December. The components will be
assembled and the wooden frame will be built over the winter break. The material list,
figure 26, has been turned in for funding approval and a total cost estimation of the
prototype system is in progress. I have been working with the machine shop and
Intralox engineers in order to optimize components for manufacturing. For the
upcoming semester we hope to assemble, test and troubleshoot the entire prototype
system. MatLab will also be used to find the optimum angle that the table should be
mounted to ensure gravity will act on all rods used. Friction coefficients and material
specs will be used in this process. The prototype wooden frame will allow for angle
adjustment so our experimental data can be compared to the analytical conclusions. A
total cost estimation for a single rod singulation system will be complete early next
semester. When the system is successful we will then move forward with design of a
sheet metal frame as well as the automation of all the controls using PLCs and/or
microprocessors. I would like to thank my advising professors for their guidance and
encouragement throughout the semester. I would also like to thank Intralox/Laitram
for all their support and funding to make this project possible.
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VI. Deliverables
1. Develop a design to replace current singulation process. (Completed)
2. Create assembly drawing of new singulation mechanism prototype. (Completed)
3. Create technical drawings for all components to be manufactured. (Completed)
4. Deliver model for complete prototype system. (Completed)
5. Provide bill of materials needed for complete system. (Completed)
6. Total cost estimation. (In Process)
VII. Fall Semester Timeline

August 20th – September 4th: Review of current singulation process and new
design research.

September 4th – 9th: Analysis of application requirements and constraints.

September 9th – October 2nd: Conceptual design and 3D modeling of rod
separating device in Solidworks. Technical drawings of all components that will
need to be produced.

October 2nd – October 31st: Design and analysis of supporting structure
including materials to be used, angle to allow gravity feed of rods, mounting
system for singulation mechanism.

October 31st – November 20th: Revise all documents/designs and make
necessary changes.

November 20th – December 4th: Create finalized assembly plans for prototype
system production.
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VIII. Spring Semester Outlook

Assemble prototype system during winter break.

Test and troubleshoot design early spring semester.

Compare friction and angle analysis with experimental values.

Solidworks model of sheet metal frame.

Simulation of system using Solidworks or similar FEA system.

Develop automated control system.

Deliver technical manual with all information needed to assemble, maintain
and operate system.
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References
McMaster-Carr. (2014, November 11). McMaster-Carr. Retrieved from
http://www.mcmaster.com/#
Lowes. (2014, November 18). Lowes. Retrieved from http://www.lowes.com/
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