ASSEMBLY SYSTEM FOR GARDEN EDGING

Transcription

1 OHIO University Mechanical Engineering Conceptual Design Report ASSEMBLY SYSTEM FOR GARDEN EDGING Tim Bressau Chris Clary Noah Needler Ryan Nida Jordan Oswald David Redwine January 23, 2012 Conceptual Design 1

2 1.0 Concept Generation 1.1 Problem Statement for Concept Generation SW Resources needs an effective way to assemble various edging components into a shippable assembly. The design solution needs to be safe and easy to operate for any of the workers with disabilities. It also needs to be able provide a high production rate of assembled edging components to reach the demands by Dimex. The edging component pieces as they come from Dimex can be seen in figure 1 and the fully assembled edging can be viewed in figure 2. Figure 1 Edging Pieces from Dimex Figure 2 Edging Fully Assembled and Ready to Ship There are a few main concerns to address in the design of a functioning solution. The approach for gathering project ideas was to brainstorm the possible solutions for addressing the main problems. One of these main problems addressed was how the connector piece is going to be Conceptual Design 2

3 installed in the piece of edging. The connecting piece is to be put in the inside track of the edging with the flat side down. There are a few possible ideas that we have brainstormed off of this main problem. Figure 3 shows the possible general methods to install the connector piece. Manual Operation Lever Mechanism Ways to Install Vertical Drop-in Sliding Mechanism Figure 3: Methods to Install Connector The decision process for the above challenge needs to evaluate the possible options to choose the idea that will be most beneficial to the workers. Manual operation is simply aligning and applying a force to put the connector in the track. The vertical drop-in can use the assistance of gravity to slide the connector piece into the edging. The sliding mechanism can work by having the operator simply slide a handle to push the connector in place after it is aligned with the edging. The lever mechanism is very similar to this but there can be a lever that is connected to the slider s handle. This would provide the ability to pull down to allow the connector piece to slide into place. Conceptual Design 3

4 Another problem to analyze is how the anchors of the edging assembly are going to be secured to each other before being attached to the edging piece. Figure 4 presents the possible methods of achieving this goal. Styrofoam Tape Ways to Secure Anchors Together Shrink Wrap Hot Glue Figure 4: Methods to Secure Anchors Together We see that there are a lot of different material choices here to secure the anchors to each other. These options need to be evaluated on the cost of the materials and simplicity of use in able to achieve the desired outcome. Each material would have to be applied in a different manor so the design possibilities can vary based off of this statement. Evaluating all the possible options from these brainstorm maps gives a better understanding of the problem at hand and gives the team a wider perspective on how the design solution should be made. Conceptual Design 4

5 1.2 Patent Search This section identifies significant commercially available products, processes, or systems used for the overall design. Patent searches resulted in the following findings: 1) Film cutter apparatus and method of forming Application number: 11/800,943 Publication number: US 2008/ A1 Filing date: May 8, 2007 Figure 5: Film Cutter (Kaiser 1,2) The film cutter apparatus in Figure 5 is of interest for the design due to its user friendly properties. Since the cutting device will be operated by individuals with disabilities that most likely have mobility issues, safety is a major concern. As the cutter is very easy to use, most of the workforce will be able to operate the cutter. A simple sliding motion is needed to perform a cutting operation. This patent may be combined with the cutter tool patent below to achieve optimal results. Conceptual Design 5

6 2) METHOD OF MAKING MECHANICAL SLIDE Patent number: Filing date: Apr 25, 1962 Issue date: Dec 31, 1963 Figure 6: Mechanical Slide (Evans 1) General mechanical slide devices as shown in Figure 6 may be used to smoothly insert the stake assembly and connecting piece into edging package. Diverse Edging came up with several ideas for sliding operations for which this patent may be applicable. This document is of interest in particular, as it describes the method of making a mechanical slide. Online research concluded that the purchase of a mechanical slide can be very expensive. Depending on budget and expense targets, Diverse Edging may manufacture a slide in the senior design lab. Conceptual Design 6

7 3) Combined letter opener and sheet-like material cutter tool Patent number: Filing date: Jul 23, 1998 Issue date: Dec 21, 1999 Figure 7: Cutter tool (Wenk 2) As some cutting operations may be difficult (example: Tape), a cutter tool as the envelope-type blade in Figure 7 could simplify cutting processes. As the operator may not be able to exert a steady sliding force to the above shown cutting apparatus, a sharp cutting tool will increase cutting efficiency and thus the overall productivity. Conceptual Design 7

8 4) Tape cutters Patent number: Patent number: Filing date: Dec 19, 1940 Filing date: Mar 25, 1959 Issue date: Jul 21, 1942 Issue date: Sep 26, 1961 Figure 8: Tape Cutting Devices Two relevant tape cutter patents may be used to simplify taping & cutting operations and is presented in Figure 8. Both designs are safe and user friendly. The deciding factors will be in terms of productivity, expenses, and weariness of the product. Eventually, the team will have to decide for either a tape cutter or the above listed film cutter. Conceptual Design 8

9 1.3 Concept Generation The process in which our group used to generate concepts for solutions to the problems and needs raised by our customer were similar to the methods used by IDEO. This method included group problem solving techniques such as brainstorming, consulting, group discussions, and voting. The initial step in the concept generation process was to understand the problem at hand. This was accomplished by visiting the facility in which our client and their employees complete the current process which we are refining. To gather information, we observed how the current process worked. From this observation, we realized two main processes needed refinement. These processes include: taping of anchors and inserting the connector piece into the edging. Also in order to fully understand the needs of our customer, we spoke face to face with employees of S.W. Resources. We asked them how they currently complete the processes needed to assemble the edging, and we asked them to describe the problems that they were having while completing their tasks. Additionally, we spoke to the management of S.W. Resources to observe their goals and needs for our project. After this initial step was taken, we met as a group and decided that it was best that we all generated ideas for how we would like to address the current problems and how to achieve the production goals of the management. This was done by having all members come up with ideas and sketches for each process that we were working to improve. In the next meeting, we all presented our sketches and ideas to the other group members for further discussion. From the presented ideas, the ideas were filtered out to a few sketches for each system that were voted to potentially be the best solutions. The group discussed, refined, and combined these ideas to propose the tentative designs for the device(s). Figure 9 shows some of the ideas that were presented to the group during our brainstorming session. Conceptual Design 9

10 Figure 9: Design Ideas Numerous proposals were brought up by the group to address the way that pins are assembled together before packaging them to the actual edging. For example, a fixture was designed to insert the anchors into holes that would place the pins automatically where desired. After the anchors were placed in the holes, the pins would be taped together and ready to be inserted into the edging. Another idea that was presented involved hanging the anchors from rods that would direct the anchors into the proper location for taping. This idea also included rods long enough to load numerous anchors for quick assembly of multiple anchors creating a hopper effect. Another system that was sketched up, involved using a press to punch the anchors into Styrofoam to secure them together. The Styrofoam/anchor assembly would then be assembled with the edging. This design would eliminate most of the taping since the Styrofoam would secure the anchors without any tape. Benefits and flaws of all presented designs were compared and discussed in the Conceptual Design 10

11 team meeting in hopes to refine and combine ideas to ultimately come up with the best solution for assembling the anchors. There were also numerous feasible ideas for tape dispensing and cutting presented by members of diverse edging. One idea included an automatic tape dispenser that dispensed the tape in the desired length every time. This would ensure consistent packaging each time. Another idea involved rolling dispensers that utilized a sliding cutter similar to that used in cutting saran wrap and other similar products. This cutter would eliminate the exposure of employees to the blade. Additionally, one idea included manually dispensing tape across the edging, and cutting it using a rolling cutter. Each design had positives and negatives, and each design was weighed by its strengths and weaknesses. The group discussed ways to combine or refine the ideas to create the best solution. For the process to insert the connectors, there were similarities and differences in the designs that members presented. Two ideas included a slider system that would insert the connector into the edging. One of the slider designs included a handle that would be pushed forward that would accomplish the insertion. This design also utilized a machined slot that would be a certain length. This slot would limit the sliding motion to a certain distance ensuring consisting placement of the connector each time. The other slider design utilized a lever system that would activate the slider. Another design used a different approach by including a vertical hopper system that would feed the connectors, using gravitational force, into the edging. After all of the designs were presented, a discussion took place to discuss the positives and negatives of each idea. It was important that all members came up with ideas independently in order to have a diverse pool of ideas. Since all members came up with their own sketches prior to discussion, each member s idea was unique and wasn t influenced by another. This allows for a broad perspective, and provides a number of unique ideas which may all have aspects that could be useful in the solving the problems with each process. Conceptual Design 11

12 2.0 Concept Screening and Evaluation 2.1 Concept Screening The first step for Diverse Edging s screening process was to make contact with Amy Helminski at South Western Resources (SWR). This allowed for a team visit of the facility to visualize the problems that the customers, the employees of SWR, were dealing with first hand. The first visit also allowed the team to sit down with Gloria Cox, SWR President, and Amy Helminski, SWR production manager, and discuss some desirable outcomes that could be accomplished by a device made by Diverse Edging (DE). This period of questioning Amy and Gloria allowed DE to come up with a basic list of needs that needed to be covered to help the customers the most. The next step to finalize the needs statement was accomplished by sending a voice capture document to Amy and having her send it back after she filled it out. The questions in this document included: What works well with the current packaging system? What does not work well with the current packaging system? What changes does SWR anticipate in the next couple of years? What would SWR envisions as an ideal system for assembling the edging? With this information from the first visit and the answers from the voice capture document, DE was able to compile a list of customers needs, these needs can be found in the project proposal report. Once this list was created it was sent to SWR for viewing and then discussed in person when DE completed its second visit at SWR to insure that all the needs of the customers were covered. After finalizing the needs of the customers, screening of the concepts could progress. The next step of the screening process performed by DE was brainstorming and coming up with a lot of different ideas to fulfill the needs of the customers. This was accomplished by asking every member of DE to come up with ideas between the two weekly meetings. Then during the meetings the drawings of the different ideas were passed around the table to allow all the members to vote on the concepts that appeared to meet the needs the best. This allowed for complete concepts to be created that integrated the ideas into a design to fulfill the needs statement. Once the complete concepts were created, the next step of screening process was started. This step involved putting the different concepts into a Pugh matrix and scoring each concept and then factoring in the weights that are displayed in the project proposal report. The Pugh matrixes that were created for this project can be found in section 2.3. This process of Conceptual Design 12

13 ranking the concepts allowed DE to narrow down the number of concepts to one or two designs for each subassembly. The next step to the screening process was sending the selected concepts from the Pugh matrixes to SWR to get feedback on what they felt would work best for them. Once feedback was received from SWR, DE was able to decide as a team on what would be the final concept. 2.2 Data and Calculations for Feasibility and Effectiveness Analysis This section includes data that was collected to describe the design s goals in terms of effectiveness and feasibility. Table 1 shows the time measurements obtained during one of the visits at SW Resources. Table 1: Time Measurements for Assembly Anchor Alignment & Taping Anchor Installation & Taping Connector Insertion Taping # Trials Average time per trial (sec) Total time (sec) From the measurements in table 1 it was concluded that the fastest average time to assemble one package for an individual with normal mobility is 82.2 seconds. However, this time doesn't include transportation to different stations. Diverse Edging made it a target to at least meet this average assembling time for SW Resources employees via using previously presented design ideas. Videos of the current assembling process were recorded to further analyze employees at their individual work stations. The video files may be used later to show before/after comparisons while presenting overall progress. To make sure that the designs will work at highest efficiency, measurements of the edging pieces were taken from 32 pieces of edging, and the measurements data can be viewed in table 2 and the dimension with tolerances can be seen in figure 10. Conceptual Design 13

14 Table 2 Dimensions of 32 pieces of edging with average and Standard deviation in orange Overall Width (in) Groove Width (in) Groove Height (in) Height from Base (in) Length (in) Conceptual Design 14

15 Figure 10: Edging Dimensions 2.3 Concept Development, Scoring and Selection For our clients, we plan to utilize 2 different subsystems for the overall assembly process. These processes include a pin jig to align the pins for taping, and a device to insert the connector into the edging. For each system, we had multiple design ideas that we believed would accomplish each task. In an effort to pick the best options to continue thinking about and refining designs, we utilized decision matrices to weigh the positives and negatives of each design to pick the best design for each system. These matrices compared each design to our four basic needs: Maintenance, Low Costs, User Friendliness, and Efficiency. Conceptual Design 15

16 For the pin assembly jig, the final design ideas that we chose to analyze included four designs. The first idea was a jig that had holes to insert the pins into. After inserting pins into the holes, the pins would then be aligned and set for taping. According to our needs, this design would be cheap and require no maintenance, but is not much of an improvement in user friendliness compared to their current pin taping methods, since it would require excellent hand eye coordination to line the shaft of the pins with the small 1/8 inch hole in the fixture. This problem would also possibly decrease efficiency since it would require extra time for pin alignment. This design can be viewed in figure 11. Figure 11 Hole Jig The next design utilized a press that would press the pins into Styrofoam to secure them together. The Styrofoam would then be inserted into the edging similar to how the connector would be inserted. This design would be difficult to maintain due to the complicated moving parts involved with the design. Although the pressing motion is both user friendly and efficient, it would be a very expensive process and device. The main reason for no further research was that it would require the use of Styrofoam, which is expensive and is not used at SW resources. Conceptual Design 16

17 The next idea would involve a jig that would hang numerous pins on a rod. The jig would also include a movable magnetic separator that would grab the three pins needed for packaging. The pins would then be taped and removed from the separator and inserted into the edging package. This design would be fairly easy to maintain, but would be expensive because it would require expensive precision shafting and precision linear bearings for operation. However, the design would be very user friendly. This design can be viewed in figure 12. Figure 12 Hanging Jig # 2 The final design was a refinement of the hole and hanging jig # 2. In this design, the pins would be hung on very short rods that would align the pins in the correct location. Two magnets would be utilized to hold the pins in place while the tape is applied, this would allow the operator to utilize both hands during the taping operation. This design would be cheap with no maintenance since there would be no moving parts to wear down. Additionally, this would be user friendly and efficient. This design can be seen in figure 13. Conceptual Design 17

18 Three short hanging pegs Magnets Figure 13 Hanging Jig # 1 We assigned rankings according to these values and inserted them into the decision matrix presented in the table below. According to this matrix, the hanging jig without any moving parts was the best design, and we decided that we would choose this as our final design. Table 2 shows the decision matrix used to determine the best pin assembly jig concept. Conceptual Design 18

19 Table 2: Decision Matrix for Pin Assembly Hanging Jig #1 Hole Jig Styrofoam Press Hanging Jig #2 Selection Weight Rating Weight Rating Weight Rating Weight Rating Weight Maintenance Keep Costs Low User Friendly Efficiency Total Continue? Yes no no no The next system that was evaluated using the decision matrices was the connector install device. The first design would use a manual slider mechanism that had a handle to push connector into the edging. This design would low maintenance since the wear items would be easily removed and replace when necessary. Also, this would be a very inexpensive solution to the connector install while still maintaining user friendliness. Using this design, production rates would be maintained or increased due to the efficiency of this design. The manual slider can be viewed in figure 14. Conceptual Design 19

20 Landscape Edging Connector Figure 14 Handle Slider The next design uses the same concept, but replaces the handle with a lever mechanism. The use of a lever would be slightly easier for some of our clients to use, but would be more expensive and harder to maintain due to the complexity of the parts in the lever mechanism because of the multiple pivot points. The pivot points of the lever could also decrease safety because of the increase of pinch points in the design. The next design for the connector installation used a vertical hopper that would use gravitational force to load the connector into the edging. This design would be cheap and require no maintenance, but would be very inefficient and difficult for the clients to operate since it would require our clients to stand up while operating the device. The final design is an amped up version of the handle slider, and would use a pneumatic system to give a mechanical advantage to the operator. The design also includes two buttons for safety; this would require both of the operator s hands to be on the buttons which would insure their hand where out of the pinch points of the device. This design would be the most efficient and user friendly design, but would be far more expensive and require much more maintenance compared to the other designs. The pneumatic slider can be viewed in figure 15. Conceptual Design 20

21 Hold down cylinder Connector install cylinder Activation Buttons Figure 15 Pneumatic Slider The table below shows the decision matrix based on these assessments. From the results of this matrix, we decided to continue development of the handle and pneumatic slider. These two deserve further consideration at this point. Table 3 shows the decision matrix used to compare the final connector installing device concepts. Table 3: Decision Matrix for Connector Install Handle Slider Lever Slider Vertical Hopper Pneumatic Slider Selection Weight Rating Weight Rating Weight Rating Weight Rating Weight Maintenance Keep Costs Low User Friendly Efficiency Total Continue? Yes No No Yes Conceptual Design 21

22 3. Final Design Concept Like previously mentioned, the final design concept selected for the pin alignment was the hanging jig #1. The reason for choosing this design was because it fulfills all of the customer s needs, and is simple to use and is very safe. Figure 16 presents a three dimensional rendering of the final concept with affixed pins to show simulation. Figure 16: Final Design Concept of Hanging Jig Conceptual Design 22

23 A mock prototype was created to demonstrate the feasibility of this design. This is shown in Figure 17. Each member of the team attempted to put on the set of pins, one-by-one, and succeeded very easily. With the addition of a magnet to the backside to hold the pins sturdy, taping will be much easier than the current method. Figure 17: Initial Prototype of Hanging Jig Since the initial prototype worked well when the team did testing, it was decided to move forward and make a wooden prototype so that SW Resource could do some testing and try and finalize the decision on this concept. The wooden prototype can be seen in figure 18. Testing started at the end of November The pin fixture has been a success and all employees so far have been able to use it with very little training. It has been found that it would be beneficial to install larger magnets, machine small grooves in the hanging pegs, and machine an outline of the pins in the upper section of the fixture, and install a manual linear tape dispenser to the base of the fixture. Conceptual Design 23

24 Figure 18 Wooden Hanging Jig # 1 The choice for the connector install was also finalized by creating a prototype and decisions made by our client, SW Resources. A mock up of the handle slider can be seen in figure 19. Conceptual Design 24

25 Figure 19 Mock up of handle slider Conceptual Design 25

26 This mock up allowed some testing to be completed on ease of use and feasibility. The team found it extremely easy to use and took the device down to SW Resources to get their input on the design. All of the management and the rehabilitation coordinator felt that this device could be used by most of the employees who had the physical strength to operate the device for extended periods of time. The prototype did reveal a safety concern of the manual device. It was found by one of the team members that after operating the slider back and forth without installing the connector piece for 15 minutes that a slight discomfort was occurring in their shoulder. This concern was expressed to the management and rehabilitation coordinator at SW Resources and they expressed that repetitive motion injury is a major concern. This is why the team chose to go with the pneumatic slider. It would prevent the employees from exerting a lot of force and keep the employees from sustaining injuries from operating the manual slider for 7.5 hours a day five days a week. SW Resources also prefers the pneumatic system because they feel that it would have a higher productivity over the manual system. The pneumatic system is also insures the employees keep their hands out of the pinch points of the machine since the pneumatic system only operates when both activation buttons are depressed. The pneumatic system would also be able to apply a consistent force to the connector piece and would allow bad pieces of edging to be discovered before being shipped to Wal-Mart, if the connector doesn t go in then the edging is bad. In conclusion Diverse Edging feels that is has chosen appropriate devices for SW Resources to fulfill all of their needs. These decisions were made by means of research, communicating with the customer, creating prototypes, and testing the prototypes. This is why Diverse Edging is confident in choosing the hanging pin jig #1 and the pneumatic slider for the final concepts. Conceptual Design 26

27 References Kaiser, Ian. Film cutter apparatus and method of forming 20. Google Patents. Web. 1 Nov < Evans, John C. METHOD OF MAKING MECHANICAL SLIDE n. pag. Google Patents. Web. 1 Nov < Wenk, Robert B. Combined letter opener and sheet-like material cutter tool n. pag. Google Patents. Web. 1 Nov < Hoebel, Harold W. "TAPE CUTTER." n. page. Print. < Marote, Raymond C. "TAPE CUTTER." n. page. Print. < 5Xe5TqerOuTW0QGSvqi_Cw&sa=X&oi=book_result&ct=result&resnum=1&ved=0CDAQ6AEwAA> Conceptual Design 27

28 OHIO University Mechanical Engineering Conceptual Design Report ASSEMBLY SYSTEM FOR GARDEN EDGING Tim Bressau Chris Clary Noah Needler Ryan Nida Jordan Oswald David Redwine November 22, 2011 Conceptual Design 1

29 1.0 Concept Generation 1.1 Problem Statement for Concept Generation SW Resources needs an effective way to assemble various edging components into a shippable assembly. The design solution needs to be safe and easy to operate for the any of the workers with disabilities. It also needs to be able provide a high production rate of assembled edging components to reach the demands by Dimex. There are a few main concerns to address in the design of a functioning solution. The approach for gathering project ideas was to brainstorm the possible solutions for addressing the main problems. One of these main problems addressed was how the connector piece is going to be installed in the piece of edging. The connecting piece is to be put in the inside track of the edging with the flat side down. There are a few possible ideas that we have brainstormed off of this main problem. Figure 1 shows the possible general methods to install the connector piece. Manual Operation Lever Mechanism Ways to Install Vertical Drop-in Sliding Mechanism Figure 1: Methods to Install Connector The decision process for the above challenge needs to evaluate the possible options to choose the idea that will be most beneficial to the workers. Manual operation is simply aligning and applying a force to put the connector in the track. The vertical drop-in can use the assistance of gravity to slide the connector piece into the edging. The sliding mechanism can work by having the operator simply slide a handle to push the connector in place after it is aligned with the edging. The lever mechanism is very similar to this but there can be a lever that is connected to Conceptual Design 2

30 the slider s handle. This would provide the ability to pull down to allow the connector piece to slide into place. There is another problem to analyze that has a few possible solutions. That is, how the anchors of the edging assembly are going to be secured to each other before being attached to the edging piece. Figure 2 presents the possible methods of achieving this goal. Styrofoam Tape Ways to Secure Anchors Together Shrink Wrap Hot Glue Figure 2: Methods to Secure Anchors Together We see that there are a lot of different material choices here to secure the anchors to each other. These options need to be evaluated on the cost of the materials and simplicity of use in able to achieve the desired outcome. Each material would have to be applied in a different manor so the design possibilities can vary based off of this statement. After the anchors are secured together they need to be secured to the piece of edging. This presents another set of possible methods to achieve this goal. Figure 3 shows a few possible solutions to do this. Cardboard Styrofoam Ways to Secure Anchors to Edging Tape Figure 3: Methods to Secure Anchors to Edging Conceptual Design 3

31 There are only a few different ways that were brainstormed from the group of securing the anchors to the edging piece. These consist of material choices as well. Each application to secure the anchors will be slightly different which will need a slightly different way to secure the anchors to the edging piece. Evaluating all the possible options from these brainstorm maps gives a better understanding of the problem at hand and gives the team a wider perspective on how the design solution should be made. 1.2 Patent Search This section identifies significant commercially available products, processes, or systems used for the overall design. Patent searches resulted in the following findings: 1) Film cutter apparatus and method of forming Application number: 11/800,943 Publication number: US 2008/ A1 Filing date: May 8, 2007 Figure 4: Film Cutter (Kaiser 1,2) The film cutter apparatus in Figure 4 is of interest for the design due to its user friendly properties. Since the cutting device will be operated by handicapped individuals that most likely have mobility issues, safety is a major concern. As the cutter is very easy to use, most of the workforce will be able to operate the cutter. A simple sliding motion is needed to perform a cutting operation. This patent may be combined with the cutter tool patent below to achieve optimal results. Conceptual Design 4

32 2) METHOD OF MAKING MECHANICAL SLIDE Patent number: Filing date: Apr 25, 1962 Issue date: Dec 31, 1963 Figure 5: Mechanical Slide (Evans 1) General mechanical slide devices as shown in Figure 5 may be used to smoothly insert the stake assembly and connecting piece into edging package. Diverse Edging came up with several ideas for sliding operations for which this patent may be applicable. This document is of interest in particular, as it describes the method of making a mechanical slide. Online research concluded that the purchase of a mechanical slide can be very expensive. Depending on budget and expense targets, Diverse Edging may manufacture a slide in the senior design lab. Conceptual Design 5

33 3) Combined letter opener and sheet-like material cutter tool Patent number: Filing date: Jul 23, 1998 Issue date: Dec 21, 1999 Figure 6: Cutter tool (Wenk 2) As some cutting operations may be difficult (example: Tape), a cutter tool as the envelope-type blade in Figure 6 could simplify cutting processes. As the operator may not be able to exert a steady sliding force to the above shown cutting apparatus, a sharp cutting tool will increase cutting efficiency and thus the overall productivity. Conceptual Design 6

34 4) Tape cutters Patent number: Patent number: Filing date: Dec 19, 1940 Filing date: Mar 25, 1959 Issue date: Jul 21, 1942 Issue date: Sep 26, 1961 Figure 7: Tape Cutting Devices Two relevant tape cutter patents may be used to simplify taping & cutting operations and is presented in Figure 7. Both designs are safe and user friendly. The deciding factors will be in terms of productivity, expenses, and weariness of the product. Eventually, the team will have to decide for either a tape cutter or the above listed film cutter. Conceptual Design 7

35 1.3 Concept Generation The process in which our group used to generate concepts for solutions to the problems and needs raised by our customer were similar to the methods used by IDEO. This method included group problem solving techniques such as brainstorming, consulting, group discussions, and voting. The initial step in the concept generation process was to understand the problem at hand. This was accomplished by visiting the facility in which our client and their employees complete the current process in which we are refining. To gather information, we observed how the current process worked. From this observation, we realized that the revision of three main processes needed refinement. These processes included: taping of anchors, inserting the connector piece into the edging, and cutting the tape after anchors and connector are inserted into the edging. Also in order to fully understand the needs of our customer, we spoke face to face with employees of S.W. Resources. We asked them how they currently complete the processes needed to assemble the edging, and we asked them to describe the problems that they were having while completing their tasks. Additionally, we spoke to the management of S.W. Resources to observe their goals and needs for our project. After all of this initial step was taken, we met as a group and decided that it was best that we all generated ideas for how we would like to address the current problems and how to achieve the production goals of the management. This was done by having all members come up with ideas and sketches for each process that we were working to improve. In the next meeting, we all presented our sketches and ideas to the other group members for further discussion. From the presented ideas, the ideas were filtered out to a few sketches for each system that were voted to potentially be the best solutions. The group discussed, refined, and combined these ideas to propose the tentative designs for the device(s). Figure 8 shows ideas that were presented to the group during our brainstorming session. Conceptual Design 8

36 Figure 8: Design Ideas Numerous proposals were brought up by the group to address the way that pins are assembled together before packaging them to the actual edging. For example, a fixture was designed to insert the anchors into holes that would place the pins automatically where desired. After the anchors were placed in the holes, the pins would be taped together and ready to be inserted into the edging. Another idea that was presented involved hanging the anchors from rods that would direct the anchors into the proper location for taping. This idea also included rods long enough to load numerous anchors for quick assembly of multiple anchors creating a hopper effect. One more system that was sketched up involved using a press to punch the anchors into Styrofoam to secure them together. The Styrofoam/anchor assembly would them be assembled with the edging. This design would eliminate most of the taping since the Styrofoam would secure the anchors without any tape. Benefits and flaws of all presented designs were compared and discussed in the team meeting in hopes to refine and combine ideas to ultimately come up with the best solution for assembling the anchors. Conceptual Design 9

37 There were also numerous feasible ideas for tape dispensing and cutting presented by members of diverse edging. One idea included an automatic tape dispenser that dispensed the tape in the desired length every time. This would ensure consistent packaging each time. Another idea involved rolling dispensers that utilized a sliding cutter similar to that used in cutting saran wrap and other similar products. This cutter would eliminate the exposure of employees to the blade. Additionally, one idea included manually dispensing tape across the edging, and cutting it using a rolling cutter. Each design had positives and negatives, and each design was weighed by its strengths and weaknesses. The group discussed ways to combine or refine the ideas to create the best solution. For the process to insert the connectors, there were similarities and differences in the designs that members presented. Two ideas included a slider system that would insert the connector into the edging. One of the slider designs included a handle that would be pushed forward that would accomplish the insertion. This design also utilized a machined slot that would be a certain length. This slot would limit the sliding motion to a certain distance ensuring consisting placement of the connector each time. The other slider design utilized a lever system that would activate the slider. Another design used a different approach by including a vertical hopper system that would feed the connectors, using gravitational force, into the edging. After all of the designs were presented, a discussion took place to discuss the positives and negatives of each idea. It was important that all members came up with ideas independently in order to have a diverse pool of ideas. Since all members came up with their own sketches prior to discussion, each member s idea was unique and wasn t influenced by another. This allows for a broad perspective, and provides a number of unique ideas which may all have aspects that could be useful in the solving the problems with each process. 2.0 Concept Screening and Evaluation 2.1 Concept Screening The first step for Diverse Edging s screening process was to make contact with Amy Helminski at South Western Resources (SWR). This allowed for a team visit of the facility to visualize the problems that the customers, the employees of SWR, were dealing with first hand. The first visit also allowed the team to sit down with Gloria Cox, SWR President, and Amy Helminski, SWR production manager, and discuss some desirable outcomes that could be accomplished by a device made by Diverse Edging (DE). This period of questioning Amy and Conceptual Design 10

38 Gloria allowed DE to come up with a basic list of needs that needed to be covered to help the customers the most. The next step to finalize the needs statement was accomplished by sending a voice capture document to Amy and having her send it back after she filled it out. The questions in this document included: What works well with the current packaging system? What does not work well with the current packaging system? What changes does SWR anticipate in the next couple of years? What would SWR envisions as an ideal system for assembling the edging? With this information from the first visit and the answers from the voice capture document, DE was able to compile a list of customers needs, these needs can be found in the project proposal report. Once this list was created it was sent to SWR for viewing and then discussed in person when DE completed its second visit at SWR to insure that all the needs of the customers were covered. After finalizing the needs of the customers, screening of the concepts could progress. The next step of the screening process performed by DE was brainstorming and coming up with a lot of different ideas to fulfill the needs of the customers. This was accomplished by asking every member of DE to come up with ideas between the two weekly meetings. Then during the meetings the drawings of the different ideas were passed around the table to allow all the members to vote on the concepts that appeared to meet the needs the best. This allowed for complete concepts to be created that integrated the ideas into a design to fulfill the needs statement. Once the complete concepts were created, the next step of screening process was started. This step involved putting the different concepts into a Pugh matrix and scoring each concept and then factoring in the weights that are displayed in the project proposal report. The Pugh matrixes that were created for this project can be found in section 2.3. This process of ranking the concepts allowed DE to narrow down the number of concepts to one or two designs for each subassembly. The next step to the screening process was sending the selected concepts from the Pugh matrixes to SWR to get feedback on what they felt would work best for them. Once feedback was received from SWR, DE was able to decide as a team on what would be the final concept. 2.2 Data and Calculations for Feasibility and Effectiveness Analysis This section includes data that was collected to describe the design s goals in terms of effectiveness and feasibility. Conceptual Design 11

39 Table 1 shows the time measurements obtained during one of the visits at SW Resources. Table 1: Time Measurements for Assembly Anchor Alignment & Taping Anchor Installation & Taping Connector Insertion Taping # Trials Average time per trial (sec) Total time (sec) From the measurements in table 1 it was concluded that the fastest average time to assemble one package for an individual with normal mobility is 82.2 seconds. However, this time doesn't include transportation to different stations. Diverse Edging made it a target to at least meet this average assembling time for SW Resources employees via using previously presented design ideas. Videos of the current assembling process were recorded to further analyze employees at their individual working stations. The video files may be used later to show before/after comparisons while presenting overall progress. To make sure that the designs will work at highest efficiency, measurements of the edging pieces were taken to the thousandth. Figure 9 shows the edging dimensions. Conceptual Design 12

40 Figure 9: Edging Dimensions Conceptual Design 13

41 2.3 Concept Development, Scoring and Selection For our clients, we plan to utilize 3 different subsystems for the overall assembly process. These processes include a pin jig to align the pins for taping, a taping/tape cutting system to tape the connector and pins into the edging, and a device to insert the connector into the edging. For each system, we had multiple design ideas that we believed would accomplish each task. In an effort to pick the best options to continue thinking about and refining designs, we utilized decision matrices to weigh the positives and negatives of each design to pick the best design for each system. These matrices compared each design to our four basic needs: Maintenance, Low Costs, User Friendliness, and Efficiency. For the pin assembly jig, the final design ideas that we chose to analyze included four designs. The first idea was a jig that had holes to insert the pins into. After inserting pins into the holes, the pins would then be aligned and set for taping. According to our needs, this design would be cheap and require no maintenance, but is not much of an improvement in user friendliness compared to their current pin taping methods. Also, the efficiency of this design would be low. The next design utilized a press that would press the pins into Styrofoam to secure them together. The Styrofoam would then be inserted into the edging similar to how the connector would be inserted. This design would be difficult to maintain due to the complicated moving parts involved with the design. Although the pressing motion is both user friendly and efficient, it would be a very expensive process and device. The next idea would involve a jig that would hang numerous pins on a rod. The jig would also include a movable magnetic separator that would grab the three pins needed for packaging. The pins would then be taped and removed from the separator and inserted into the edging package. This design would be fairly easy to maintain, but would be very expensive because very precise shafts and bearings would be needed to complete the design. However, the design would be very user friendly. The final design was a refinement of the other hanging jig. In this design, the pins would be hung on very short rods that would align the pins in the correct location. A magnetic plate would be utilized to hold the pins in place while the tape is applied. This design would be cheap with no maintenance since there would be no moving parts to wear down. Additionally, this would be user friendly and efficient. We assigned rankings according to these values and inserted them into the decision matrix presented in the table below. According to this matrix, the hanging jig without any moving parts was the best design, and we decided that we would choose this as our final design. Table 2 shows the decision matrix used to determine the best pin assembly jig concept. Conceptual Design 14

42 Table 2: Decision Matrix for Pin Assembly Hanging Jig #1 Hole Jig Styrofoam Press Hanging Jig #2 Selection Weight Rating Weight Rating Weight Rating Weight Rating Weight Maintenance Keep Costs Low User Friendly Efficiency Total Continue? Yes no no no The next system that was evaluated using the decision matrices was the connector install device. The first design would use a manual slider mechanism that had a handle to push connector into the edging. This design would low maintenance since the wear items would be easily removed and replace when necessary. Also, this would be a very inexpensive solution to the connector install while still maintaining user friendliness. Using this design, production rates would be maintained or increased due to the efficiency of this design. The next design uses the same concept, but replaces the handle with a lever mechanism. The use of a lever would be slightly easier for our clients to use, but would be more expensive and harder to maintain due to the complexity of the parts in the lever mechanism. The efficiency of this design would be slightly higher compared to the handle slider. The next design for the connector installation used a vertical hopper that would use gravitational force to load the connector into the edging. This design would be cheap and require no maintenance, but would be very inefficient and difficult for the clients to operate. The final design is an amped up version of the first two designs, but this design would be pneumatic. The design also includes two buttons for safety so two hands would have to engage the buttons. This would ensure that an employee s hands were out of the range of motion. This design would be the most efficient and user friendly design, but would be far more expensive and require much more maintenance compared to the other designs. The table below shows the decision matrix based on these assessments. From the results of this Conceptual Design 15

43 matrix, we decided to continue development of all designs but the vertical hopper. These all deserve further consideration at this point. Table 3 shows the decision matrix used to compare the final connector installing device concepts. Table 3: Decision Matrix for Connector Install Handle Slider Lever Slider Vertical Hopper Pneumatic Slider Selection Weight Rating Weight Rating Weight Rating Weight Rating Weight Maintenance Keep Costs Low User Friendly Efficiency Total Continue? Yes Yes No Yes The final system that was analyzed using a decision matrix was the taping and cutting system. The first option was to use a purchased automatic tape dispenser. This dispenser would automatically dispense tape in the desired length. This option would be the most expensive option and would require the most maintenance. This would be a user-friendly device, but from recommendation from past experiences told us that this would actually be a less efficient option. The next design would use a manual tape roll, but would be cut at the desired length using a rolling cutter similar to a pizza cutter. This would be fairly inexpensive and would require a moderate amount of maintenance due to the wearing of the blade. This design would be both user friendly and efficient. The next option would also use a manual tape roll and would include a sliding blade that would cut the tape. The blade would be completely hidden for safety. This design would be easily maintained because the whole cutter could be easily replaced for a low price when worn down. Also, this option would be very user friendly and efficient. The final option would be just to have someone manually tape all of the pieces in as they are already doing. Of course this requires no maintenance or extra costs, but is not very efficient or userfriendly. Using these evaluations, we assigned rankings to each design in the table below in an attempt to find the best option. From the results, we determined that the sliding tape cutter would be the best option for the majority of taping and cutting processes. Table 4 shows the decision matrix used to determine the best taping and cutting options. Conceptual Design 16

44 Table 4: Decision Matrix For Best Taping and Cutting Method Automatic Rolling Sliding Manual Selection Weight Rating Weight Rating Weight Rating Weight Rating Weight Maintenance Keep Costs Low User Friendly Efficiency Total Continue? No No Yes No Conceptual Design 17

45 3. Final Design Concept Like previously mentioned, the final design concept selected for the pin alignment was the hanging jig #1. This design concept satisfies all of the customer s needs and is an effective, yet, simple device. Figure 10 presents a three dimensional rendering of the final concept with affixed pins to show simulation. Figure 10: Final Design Concept of Hanging Jig Conceptual Design 18

46 A mock prototype was created to demonstrate the feasibility of this design. This is shown in Figure 11. Each member of the team attempted to put on the set of pins, one-by-one, and succeeded very easily. With the addition of a magnet to the backside to hold the pins sturdy, taping will be much easier than the current method. Figure 11: Initial Prototype of Hanging Jig The above concept satisfies a part of the total problem that SW Resources has. However, a design choice needs to be made for the connector install. This is a working process for the team. The team has discussed the pros and cons of the possible routes to pursue and have narrowed the connector install device down to two possible solutions. The first design is the manually operated slider. This would be simple to use but affective. The edging piece would lie on a machined piece of aluminum with lips on the sides that would help align it correctly. The connector piece would then be inserted into the edging at one of the ends. This would be done by a simple sliding Conceptual Design 19

47 method which would push the connector piece into the track of the edging. Figure 11 shows this concept more clearly. Figure 11: Manual Slider The source of operation for the slider (handle/lever) has not been decided yet but the idea would be the same as pictured above with the handle. The only real change would be the actuation. An initial prototype of this concept was constructed to evaluate the feasibility and effectiveness of the concept. This is shown in Figure 12. Figure 12: Manual Slider Prototype It proved very effective using the above prototype. The slider was able to install the connector Conceptual Design 20

48 piece into the edging track with ease. This also proved a consistency in the location of the connector piece. The other concept that is in debate is the pneumatic slider. This would basically be the same design as the above except with a few added benefits. There are a number of orders from Dimex that SW Resources is not able to use due to the inconsistency in dimensions of the edging track. This leads to the problem of the connector piece not being able to slide in easily and sometimes not at all. One of the benefits of the pneumatic slider design is that there would be a constant air pressure supplied to the actuator. Therefore, if an edging piece is not acceptable the connector piece would simply not be able to go in the track and the bad piece could be thrown out. If there was a bad piece of edging in the manual case, the operator would simply force it in which could break something. Another benefit of using a pneumatic system is safety. There would be two buttons mounted externally of the holder that would require the operator to hold one to operate a hold down cylinder for the edging piece, and then push another button to operate the cylinder to slide the connector piece in the track. This way there could be no way for the operator to accidently put their hand somewhere it shouldn t and get hurt. Figure 13 shows the design concept. Figure 13: Pneumatic Slider Another of the concepts that was evaluated was the way the taped pins were going to be installed into the edging piece. The team wants to do a very similar method to that of the connector piece Conceptual Design 21