Aquatic Perambulation Preet Jain Shiv Choudhari Jeffrey Johnson
Aquatic Perambulation Preet Jain, Shiv Choudhari, Jeffrey Johnson, and Maria Mc. Quaide EDSGN 100
Table of Contents 1. Introductory Design Tasks 2. Concept Generation and Evaluation 3. Technical Analysis 4. Development and Testing 5. Summary
We began by generating our Mission and Problem statements. Mission Statement - To collaborate effectively in order to complete all projects. Problem Statement - To design, build and market a recreational product that is durable, user-friendly and flexible enough to allow a college student to walk on water while transporting a maximum load of 40 pounds.
We took our stakeholder’s requirements and constraints into consideration. Stakeholders 1. Customers (College Students) 2. Part Manufacturers Requirements 1. Affordability to our customers (college students) 3. Instructor 2. Safety (easy to remove, feet should not be able to slide apart in the water) 4. Natatorium Managers 3. Lightweight (Easy to transport) 5. Waste Managers 4. Easy to use (Customers with no engineering background should be able to operate) Constraints 1. Cost Effective
We distributed a survey to determine customer needs. Fig. 1: Customer weights Fig. 2: Price Range Fig. 3: Feature ranking
The data from our customer survey was used to develop specifications for the product. Number Customer Description Specification 1 Product must be safe a. b. c. 2 Willing to pay $40 -60 Production cost below $30. 3 Recreational use, but can also be used for an emergency or a job. Can be used effectively after 10 hours of practice. 4 Fit shoe size of 9 -11. Be adjustable to feet of shoe sizes 6 -12. 5 Support weight of 130 -160 + 50 lbs of cargo. Can remain balanced and intact for users 130 -160 lbs and at least 40 lbs of cargo. 6 Speed Capable of crossing the 75 foot Natatorium pool in 120 seconds. 7 Portable (Can be deployed quickly) Product should be less than 10 lbs and be able to fit in the trunk of a car (surface area less than 9 ft squared) 8 Durable Can last for at least 50 hours of use. 9 No fuel or batteries. User should be able to generate enough force against the water to cause forward motion. Table 1: Specifications Large surface area (about 9 ft^2) and quickly removable if capsized no sharp materials or exposed corners non-toxic materials
The specifications were rated against each other to determine relative importance. Table 2: Specification weights
We considered many options before choosing our design. G D F Figure 4: Sketches
We began to evaluate the best design with a concept screening matrix. Table 3: Concept Screening matrix
We then used a weighted decision matrix to select the final design. Table 4: Weighted decision matrix
Physical properties were used to calculate the ideal dimensions of each shoe. Square section Triangle section Length (m) Width (m) Height of walls (m) Length (m) Width(m) 0. 609 0. 34 0. 5 0. 3 Maximum mass (kg) Bottom surface area (m^2) =L(square)W+0. 5 L(triangle)W =0. 2577 99 Gravitational force of load (buoyancy needed) =Mass*9. 81 =970 Maximum sinking depth (m) Volume displaced in m^3 =Mass/(1000*SA) =0. 38 =(Sinking depth)*SA =0. 099 Buoyancy of 1 shoe (N) =1000*9. 8*(volume displaced) =859 (buoyancy of both shoes = 1718 N)
A free-body diagram of a shoe is helpful in visualizing the calculated properties. Buoyant force Buoyant Force = Gravitational Force in order for floatation to occur Sinking depth Gravitational force of load and shoe Figure 5: Freebody diagram
Solid. Works was used to create the final design for the first prototype. Figure 6: Prototype
Our shoes are resistant to tipping. Figure 7: Tipping Point
We integrated several subsystems into the final product. A) Stability - The center of mass of the object was used to determine relative buoyancy and stability if one stepped at various points on the device. B) Buoyancy C) - The buoyancy of the device in water was used to calculate the surface area necessary for floatation. Table 5: Systems Structural - The device was cut so all the sides fit snugly together. D) Strength - The sides and corners were strengthened with gussets to increase their strength.
We kept the cost below our target budget of $30. Table 6: Bill of Materials index Material purchased Price per unit Units used Price per pair of shoes . 84 oz epoxy X 2 $3. 98 1. 5 $5. 97 55 yards 1. 88 inch duct tape X 2 $3. 88 1 $3. 88 48 inch 3/8 inch poplar dowel $0. 98 negligible $0 50 feet synthetic Clothesline $2. 78 0. 4 $1. 11 4 square feet 1 inch project panel $5. 48 1. 5 $8. 22 32 square feet 3/4 inch polystyrene $8. 48 all $8. 48 $0. 2 6 $1. 2 Total Cost $28. 86 Garbage bags
Our first prototype lacked the stability and structural integrity to cross the pool. Figure 8: First test
We improved upon the design for the next test. Changes made: 1) Structural support added to sides and corners 2) Pole added for balance 3) Foam strips added for extra buoyancy 4) Connection between shoes made longer
Due to an overlooked gap in the bags used to make the shoes watertight, the final prototype failed to cross the pool. Issues: 1) Water entered the bottom of the device 2) The water caused the support poles to fail 3) The added water weight prevented effective motion Solutions: 1) The bags need to be wrapped around the entire bottom of the shoe 2) The support poles must be a plastic material
Given another testing day, and with the knowledge we have now, the shoes would likely be successful.
Gantt Chart Figure 9: Gantt Chart
Questions?
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