Timeline/Weekly Progress

Timeline

Task	1	2	3	4	5	6	7	8	9	10
Research and Brainstorming How are drawstrings inserted during manufacturing?	x	x
Take Measurements Come Up with a First Design Idea		x	x
Brainstorm Solutions to Problems Encountered with Previous Designs, and Make Revisions			x	x	x	x	x	x	x
Purchase and Procure Materials Needed for other Components					x	x	x	x	x
Final report preparation								x	x	x

Note: Group 8 first task started at Week 2 as there was no laboratory section on Week 1.

Weekly Progress

[Week 1]: No Lab This Week

Brian, Paul, Emaad, Andre, and Dung met each other in the lecture section of ENGR 103 (Engineering Laboratory Design III) to form a project group. Otherwise, Dr. Cheng, who is the professor for the lecture section, stated that there was not any laboratory section for the first week. Therefore, we decided to have lunch with food truck outside of The College of Engineering for first meeting. After the first week, Andre left the group, also departed from The College of Engineering in order to pursue the degree in Construction Management. Good luck, Andre

[Week 2] Team Members List - Project Overview

Team Members

Brian Kearns
Paul Lelyukh
Dung Tran
Mohamed Fayaz

Brief Overview

The main goal of this project is to create a simple, practical and affordable device that can re-string a hoodie. This project will involve designing an alternative method to restring hoodie sweatshirts. This device will include two main objectives:

1.     To provide a device that restrings any hoodie sweatshirts or other articles of clothing within in a minute or less, which is considerably faster than any current methods available. 

2.     To reduce the Re-Stringer's cost by using affordable  materials and manufacturing methods to produce the design.

This project's motivation is not only to fulfill a desire to immediately repair hoodies, but also to add a useful and effective tool for college students or any hoodie fan.


source: e-how





[Week 3] Hoodies' Measurement and Brainstorming

In this week, Group 8's project proposal was submitted to Lab Instructor (Dr. Hisham Abdel-Aal) and Graduate Fellow (Mr. Marco Janko) via Drexel Learn. 

Hoodies' Measurement

During the laboratory section, a variety of hoodies was measured while the project proposal was being approved. The data list will be updated during next week's laboratory section as the hoodies' measurement was incomplete before 6:00 P.M... Figure 1 demonstrates the measurement of Brian's hoodie string by using Manostat's vernier caliper. This tool determined the thickness of hoodie string by its slider, which adjusts the distance between two big blades to tighten the string for accurate reading. Figure 2 shows how Brian applies the measuring tool to measure the Emaad's hoodie ring. 

Figure 1 (Left): Thickness Measurement of Brian's Hoodie String
Figure 2 (Right): Diameter Measurement of Emaad's Hoodie Ring

Below is the data list demonstrating the measurement of hoodies' components that consists of ring (diameter), string (diameter, length), hood string, tip (width and length). Those components were measured in millimeters. The data list will be constructed and updated during next week's laboratory section, or after any Group 8's meetings after class

Hoodie's List	Hoodie Rings	Diameter of  Strings	Hoodie Tip Width	Hoodie Tip Length	String Length
Brian's Hoodie	12.6mm	3.2mm	3.4mm	N/A	381mm
Emaad's Hoodie	10.2mm	3mm	4.3mm	18.4mm	N/A
Dung's Hoodie	8.8mm	4.3mm	4mm	14.8mm	N/A
Paul's Shorts	9mm	3mm	N/A	N/A	N/A

Figure 3: Data Collection for Hoodies' Measurement 

Brainstorming

Group 8 researched how drawstrings are inserted into hooded sweatshirts during the manufacturing process, in order to understand the level of proficiency the device would need to have. The Youtube video clip below demonstrates how American Giant strings their hoodies during production, which is the solid foundation for Group 8's decision to generate the mechanism of Re-Stringer.

Reference:

"Making of the Full Zip Hooded Sweatshirt." YouTube. N.p., 08 Apr. 2013. Web. 07 Nov. 2016.
https://youtu.be/xukM8i4GW-g?t=1m47s

[Week 4] 3-D Model Prototype Design (Part I)

Introduction

Group 8 did not have laboratory sessions this week due to Columbus Day, which is also a University holiday. Thus, Brian reserved a group study lounge “L16” within W.W. Hagerty Library on Friday (October 14) to work on designing 3-D prototypes for the Re-Stringer with Inventor™ by Autodesk. For this post, Paul’s model will be demonstrated below.

How it works!

Paul's idea for a design was to make the hinge function like scissor after Emaad suggested that we put a ring with threads onto the clamp to keep it from opening. The hinge can rotate about one of the two central axes of the narrow cross section of the clamp mechanism instead of rotating about central axis of the longer cross section of the clamp mechanism. This design has a separate section for the hinge, tip, string and hooks. The hooks are on the opposite end from the gray nozzle cone, and after that there's space for the string tip which cannot be attached to the hooks. Then comes the hinge at the circular cut made in the green part. After the hinge you have the reduction in the radius of the gray part for a ring that would function as a screw, and if you look closely you'll see a cut in that section, and this to allow the outer clamp (i.e. "the green part") to rotate. 

Figure 1: Paul's 3-D Prototype for Re-Stringer(*)

Outer Clamp

This design not only explains what the ring will prevent from happening when it is screwed completely against the green part, but also prevents the clamp mechanism that contains the string and hooks from opening. The ring, hinge pin, and screw threads aren't pictured in the 3-D model of the assembly (Figure 2). The hinge pin would go through the curricular hole in the gray part and would be glued to fixation caps the would be flush with the green part, and the caps would be as large as the hole in the green part. 

Figure 2: Outer Clamp part of Re-Stringer

Inner Clamp

The Re-Stringer prototype's inner clamp have the nozzle cone at one of its end (Figure 3) whose diameter would be flushed with the ring, and taper down to the wire which would allow the smooth passage of the clamp mechanism during the operation. There is one row of hooks on this part, but there's three rows of hooks on the outer part, and when the parts come together the hooks keep the string in place.

Figure 3: Inner Clamp part containing nozzle scope(*)

(*) The hinge pin, hinge fixation caps, ring, and the thread for the ring is not included in this assembly.

[Week 5] 3-D Model Prototype Design (Part II)

Introduction

This week, the tested hinge will be produced by one of Group 8's planned manufacturing techniques, which is 3-D Printing. The hinge (Figure 1), which is located on the Clamp Mechanism (both on the Outer and Inner part), is an important part of the Re-Stringer as it allows movement of the Clamp Mechanism.

Figure 1: Attempted Clamp Mechanism Design with Hinge using Autodesk's Inventor

Result!

After receiving the plastic prototype from a 3-D Printer in The Innovation Studio in Drexel University, Group 8's attempted design turned out to be a failure, because the hinge is too small to print (about 0.75 mm / 0.03 inches). During the laboratory session, Brian and Paul held the discussion about the improvement for Prototype 1 which led to the following tasks:

1. Redesign the clamp mechanism, especially enlarging the hinge pin and hook to let 3-D printer operate properly
2. Set the 3-D printer to print in two directions: horizontal (Prototype 1A), and vertical (Prototype 1B)

Figure 2 and 3: The "Tiny" Hinge Pin and Hook located on Clamp Mechanism, a failed prototype (Prototype 0)

[Week 6] Prototype Construction and Testing (Part I) 

Components' 3-D Printing (Prototype 1)

Two samples (images above) of Re-Stringer has been produced during Week 4 and 5 by Afinia™ 3-D Printer located within The Innovation Studio at Drexel University. PLA (Polylactic Acid) was applied as filament. Last Monday (Week 6), Group 8 proudly demonstrated Paul's Re-Stringer prototypes after two weeks of prototype construction. Two figures above, which indicate the inner part of clamp mechanism and ring only, exhibits two different methods to construct prototype: horizontal (Prototype 1A - the white prototype), and vertical (Prototype 1B - the blue prototype).

Figures 1a, 1b, 1c, and 1d exhibit Group 8's horizontal method in 3-D printing, which lie the construction mold horizontally in Afinia™ 3-D Printer. However, as indicated in Weekly Progress at Week 5 Section, that sample (a.k.a original prototype) was a failed product again even though Brian and Paul had revised their designs, which enlarged the clamp hook on clamp mechanism. 

Figure 1a: Horizontal 3-D Print contains Outer Clamp (Left), Inner Clamp (Center), Ring (Right)

The clamp hook in the middle of Inner Clamp (Figure 1b) can be broken while applying the horizontal printing method in Afinia 3-D printer. Moreover, the clamp lock located on the Outer Clamp (Figure 1c) would not work properly if a large hooded sweatshirt string was applied. Also, it can break after several times of restring the hooded sweatshirt. Thus, Prototype 1A is also a failed attempt in Re-Stringer design.

Figure 1b: Detailed Inner Clamp with Hinge Pin, Connected Ring is not Included

Figure 1c: Detailed horizontal Outer Clamp

Figure 1d:  Detailed Ring

The vertical method, which Prototype 1B was printed perpendicular to the Afinia™ 3-D Printer's plate, can surpass the issues above. In the other word, Afinia™ 3-D Printer could understand how the prototype looked like, and printed properly.

Figure 2: Revised Model (Printed 90 degrees)

Figure 2a: Revised Inner Clamp, Top View

Figure 3a and 3b shows the demonstration of the Original Inner Clamp attached to the Revised Outer Clamp. Group 8 may consider this combination as the colorful option. However, both version of prototype 1 had several drawbacks that were required for the improvement in Prototype 2 construction:

1. The connection section between tapered nose cone and hook section is thin and easy to break.
2. The fixation cap is not feasible.
3. The hook located on inner clamp is not solid to hold the drawstring.

Figure 3a: Revised Outer Clamp connects with Original Inner Clamp

Figure 3b: Top View of Revised Outer Clamp (Right) and Original Inner Clamp (Left)

Clamp Mechanism Testing (Prototype 1)

Two figures below exhibits how Brian and Emaad tested the Revised Clamp Mechanism without the connected pin. In this scenario, a paper clip was served as the hinge pin (Figure 4b) to maintain the rotation of Outer Clamp. Dung's hooded sweatshirt from Primark was a test object. The result was obvious: the hook could not resist the sweatshirt's drawstring, and the hinge was also weak to maintain closed (Figure 4b).

Figure 4a: Clamp Mechanism Testing

Figure 4b: A paper clip as an alternative for the connected pin

Next week update, Group 8 will discuss about Prototype 2, which indicates Brian's revision in Inner Clamp mechanism, Also, a little debate will be generated about keeping Group 8's original design or applying Brian's method to improve the mechanism.

[Week 7] Prototype Construction and Testing (Part II)

Extension Rod

This week, Emaad discovered a solution for an extension rod. A BBQ skewer will be applied as Re-Stringer's extension rod due to its stiffness, flexibility, and durable. Its diameter, which is approximately 2 mm, is also suitable for the clamping mechanism.

Figure 1: BBQ Skewer served as Extension Rod

Design Revision (a.k.a Prototype 2)

Paul and Brian have been working to construct a method that will not only hold the string but will keep the clamp mechanism closed tightly until the user wants to open it.

Brian put the circular cap on the tip of the lever arm that will wrap around the outer clamp and will resist being opened. He also extruded the area between the tapered nose cone and the hinge pin mechanism such that the finished design will be smooth along the entire length instead of having the smaller diameter rod.

Figure 2: Brian's Inner Clamp Revision

Clamp Mechanism Testing (Prototype 2)

After obtaining the revised prototype from 3-D Printer at The Innovation Studio, Group 8 decided to test its clamp mechanism after the laboratory session. The result is pretty content, which tends to hold the string and resist the friction well. The full test will be updated next week as the extension rod will be delivered to Emaad's dormitory room.

[Week 8] Prototype Construction and Testing (Part III)

Drafted Final Report

A draft for final report was submitted through Blackboard Learn last Monday. This blog has also been updated with information and researches, which were indicated on the drafted final report. Group 8 will process a final report and presentation after receiving comments and recommendations from lab instructors.

Prototype 2 Testing Update

During the laboratory section, Emaad brought his flexible metal rod, which is Shwizadle's BBQ skewer that he purchased through Amazon. This flexible metal rod was served as Re-Stringer's extension rod, whose one end was attached to pin hole by hot glue. Otherwise, one end with arrow-like cap on top generates a pathway inside the sweatshirt's hood for the device to restring the drawstring throughout the hood without snagging it.

Figure 1. Re-Stringer Prototype with attached extension rod

Figure 2. Re-Stringer demonstration before testing

Paul's hooded jacket would serve as the tester for the first trial. Those pictures below demonstrates how Paul tested the device, and Re-Stringer can restring its drawstring through his jacket's hood successfully. However, there were still three negative outcomes, which required Group 8 to revise its design again, which will establish Prototype 3:

1. The small precision still prevented the 3-D printer from generating the perfect prototype as minor cracks occurred.
2. 3-D printer could not drill the hinge pin hole automatically.
3. Re-Stringer still spent a longer time to restring than expected

Figure 3. Paul installed Re-Stringer through the jacket's hood hole. The drawstring was attached to the device's clamp.

Figure 4. Re-Stringer was manually running through the drawstring pass inside the hood

Figure 5. Paul pushed the Arrow-like cap of extension rod to get Re-Stringer out of the hood hole

Figure 6. The first trial was successful, as the drawstring was still attached to the device clamp.

[Week 9] Prototype 3

This week Group 8 has presented Prototype 3 (Figure 1) during the laboratory session. Its design looks more solid than its previous prototypes, the hook looks reliable at Figure 2, and 3 (a.k.a Anaconda's "plastic" teeth). Moreover, the tapered nose cone's diameter has been decreased (Figure 2) so that the device can enter the hoodie ring easier.

However, the biggest drawback of this prototype is its diameter reduction, which Brian reduced from 8.5 mm (Prototype 1 and 2 diameter) to 5.5 mm in order to go through Emaad's hoodie ring. Obviously, Prototype 3 cannot hold any tested drawstrings that are similar to two previous prototype tests. Therefore, this is also a failed prototype, which still cannot solve remaining problems from Prototype 2.

Another prototype has been constructed by 3-D printer at The Innovation Studio. Unfortunately, minor cracks located on the device surface still occurred, and the hinge pin hole still need to be drilled (even though less than last time) so that a hinge pin can be able to go through the hole.

Group 8's Lab Instructor suggested about asking a professor in Mechanical Engineering and Mechanics Department about our 3-D printing issue. Brian and Paul are working on Prototype 4, which is likely Group 8's final prototype before presentation. If Prototype 4's dimension meets the requirement, this professor's 3-D printer will construct the presentation prototype for Re-Stringer after granting his approval. 

 Figure 1. Prototype 3 Clamp Mechanism (hinge pin and extension rod not included)

Figure 2. Nose cone Reduction on Inner Clamp

Figure 3. Inside of Outer Clamp, with detailed Hook Teeth

[Week 10][Week 11] Final Prototype and Final Report Preparation.

Figure 1. Prototype 4 testing with Emaad's Hooded Sweatshirt (Finally, it works!)

Brian decided to keep construct the current Re-Stringer prototype, Prototype 4 (Figure 2), with a 3-D printer from The Innovation Studio instead of seeking for a 3-D printer with more precision. At this moment, that 3-D printer (from the Innovation Studio) generates its best result for the device.

Figure 2. Prototype 4's Overview

This prototype can enter Emaad's hoodie ring (Figure 1) due to Group 8's decision that Re-Stringer will go with Prototype 3's diameter (5.5 mm). Otherwise, the new locking mechanism of this prototype helps the device hold any size of string.

The Rubber Band (Figure 3), which places around the clamp mechanism for control purpose (a.k.a. prevents it from freely opening as Figure 4 and Figure 5), serves as the locking mechanism of this device. The outer diameter of this rubber band can range from 3.2 mm (before stretching) to 4.5 mm (after wrapping around the clamp mechanism).

Figure 3. Rubber Bands, Prototype 4's keystone in locking mechanism

Figure 4. Better printed Hooks for Clamp Mechanism

Figure 5. Clamp Mechanism details, after Rubber Band's removal

Obviously, this prototype still contains drawbacks that is (1) the device may break after several uses due to a low hardness of 3-D printing material, (2) That small precise 3-D printer forces the hinge pin to be drilled manually and (3) the rubber band can lose easily, and the device can be considered useless without its locking mechanism.

In conclusion, the perfect prototype for Re-Stringer, which replaces the rubber band to a better locking mechanism, would be generated if the time allowance was extended to more than 10 weeks. However, all the team members are pleased with the latest prototype that can work properly. Finally, Group 8's lab instructor assigned the final presentation to be exhibited on November 28th, which also means that this weekly update should be the last one!