Redesign and Packaging of Adirondack Chair Team #58 Project # F07-58ADRNDKCH Team Members

1. Redesign and Packaging of Adirondack Chair Team #58 Project # F07-58ADRNDKCH Team Members Craig Craddock William Fogerson Jason Hick John MathewsMike Mayo Solution Con’t: 4-Packaging and Shipping: In order for the chair to be shipped a set of instructions for the packager were created in addition to a directions for the end-user to reassemble the chair. A sample of these instructions is shown in Figure #3. A sample of the packaged chair is shown in Figure #5 Client: Center For Comprehensive Services Location: Carbondale, IL Problem: The Center for Comprehensive Services (CCS) provides after hospital rehabilitation for people with brain injuries. CCS requested that our team improve the strength of their current arm design and also find an effective packaging method so that they can sell more chairs. This problem is unique because of the nature of workforce and the unique manufacturing environment. Solution Con’t: 2-Physical Testing: To further verify the FEA results a four point bending machine was used to simulate the loading condition. A test stand was created to simulate the arm being mounted in the chair as shown in Figure #4. The load was constantly increased until the first sign of fracture occurred. This process was repeated for several designs. The results are recorded in Figure #1. Figure #1 shows the original design had a strength of 333 lbf and a range of 149 lbf whereas the revised design has a strength of 565 lbf and a range of 17 lbf. This data is expressed as a range is shown in Figure #2 which shows how the strength and the consistency of the product have been improved. Figure #3 Sample Directions Manufacturing Environment Solution: 1-FEA (Finite Elemental Analysis): Autodesk inventor was used to create a solid model of the current arm design. Then the Ansys Stress Analysis package was used to apply both a pressure and a couple. A pressure and a couple were applied to simulate the force of a person hand. This showed a maximum stress of over 190,000 psi at the rear screw hole. This model supports the statements made by CCS wherein they stated the arms were failing. Based on this information it is clear were redesign was needed. Both the original design and the revised design are shown below. With the addition of a brace rod and support the maximum stress was reduced to just over 9000 psi which is over a 21 times reduction. Figure #4 Test Set-up Figure #5 Sample Packaging Figure #1 Strength Figure #2 Range 3-New Parts: The two additional parts that must be manufactured are shown in Drawing #1 and Drawing #2 along with a complete assembly which is shown in Drawing #3. Cost and Schedule: As shown in Table #3 the implementation time is short due to the similarities of the existing design. The greatest time is allotted for the adhesive to cure. As shown in Table#4 the total cost spent was just over $200 dollars and the amount spent on the prototype and testing was just slightly over $100 dollars Original Design 190,000 psi Table #3 Implementation Schedule Revised Design 9,000 psi Table #4 Cost Drawing #1 Drawing #2 Drawing #3