Bronson Cheramie Lekha Acharya Jake Jones Tyler Miller
Download 7.28 Mb.
|
- Navigate this page:
- Operating Environment Test
- Geometric Test
- Installation Time Test
- Manufacturing Time Test
- Prototype Construction and Testing Construction of Hub
Weight Test The main reason for this project is to eliminate the excessive weight of the current wheels that fit on Louisiana Tech’s urban concept vehicle. Our wheels need to be lighter than the current wheels in order to improve efficiency. In order to weigh the wheel, we will simply place it on a digital scale. The scale has a resolution of 0.005 lb, giving an uncertainty of 0.0025 lb. This is obviously much more precise than we need. We really only need a resolution of 0.1 lb, but this equipment is what we have to work with. Operating Environment Test Our wheels need to be able to operate in a fairly wide range of environments. The competition will likely be postponed in the event of rain, but the chance of very high humidity is very possible. Our wheels must be able to handle a range of humidity from 20-99%. We will use a humidity meter, which has a resolution of 1% and an uncertainty of 0.5%, to measure the humidity of the air that the wheel is in. We will generate a more humid environment if necessary. Due to the complexity of testing the wheel dynamically in a generated environment, we will have to test the wheel statically to assess its integrity. The wheel will also need to be able to withstand the pressures that it is subjected to from the tire. The tires are pumped up to as high of a pressure as safely possible during the competition to eliminate rolling resistance. This safe pressure is taken from the reading on the tire. The tires should actually be able to hold about twice the pressure marked on the tire before exploding. We do not want to pressurize our wheel to the point of explosion, but we do want to test the wheel beyond its operating point to see whether or not the wheel is at the brink of its capacity. We will watch the tire as we inflate it and take every precaution to assure the safety of our team members in this test. The tire will be pumped up using a Schwinn Airdriver 1100, which is a hand pump for bikes. The resolution on the pump gage is 4 psi, yielding an uncertainty of 2 psi. One critical test on the wheel deals with the temperature range within which it can operate. When carbon fiber reaches a certain temperature, it becomes floppy. If our wheels reach this temperature during use, the results will not be good. In this test, the wheels will be heated in an oven to 115 °F. The wheel will then be tested statically to determine its strength. If need be, the wheel will be kept at temperature during testing with a heat gun. The temperature will be monitored using an infrared thermometer. The Redington 9930 irt has a resolution of 0.5 °F and an uncertainty of 0.25 °F. Geometric Test According to Shell Eco Marathon regulations the width of our wheel must be greater than or equal to 80 millimeters. Dial calipers with a resolution of 0.001 inch and uncertainty of 0.0005 inch will be used to measure the width. Regulations also state that the wheel must be either 16 or 17 inches in diameter. We chose our wheel to be a diameter of 16 inches. A standard tape measure with a resolution of 1/16th inch and uncertainty of 1/32nd inch will be used to measure the diameter. Installation Time Test The tire and wheel installation must take the same amount or less time than the existing tire and wheel. This test is important because if a tire and/or wheel fails during the competition, the replacement time must be as small as possible. First, the time to install the existing tire and wheel will be measured. Then, the time to install the prototype tire and wheel will be measured. Each time will be measured with a stopwatch which has a resolution of 1 second and an uncertainty of 0.5 second. Manufacturing Time Test Laying out carbon fiber on the foam core and the resin infusion process should be completed in less than 12 hours. This time constraint is a customer requirement as stated in the engineering design specification report. A stopwatch with a resolution of 1 second and an uncertainty of 0.5 second will measure the time it takes for the process to be completed. Prototype Construction and Testing Construction of Hub The hub is made of two inch thick hex bar. We purchased three feet of hex bar and cut three inch sections for each hub. Next we bored out a center hole of 1-1/8th inch for the spindle to pass through. Then we bored out 1.258 inches on each side for the bearings to sit. Finally we drilled and tapped six ¼ inch diameter holes to a depth of 1.5 inches deep. A pictures of our hub being tapped and the shop drawing of the hub are shown in figure 7.1a and 7.1b respectively. 
Directory: resources resources -> General text for tender (recommendations) for Pilkington Profilit™ Contents Page resources -> North Carolina Inclusion Initiative Mapping Where Children with ieps are Being Served Purpose resources -> Practice learning resources -> The Rise of Video Games Section “Word” Matt Spencer resources -> Request for proposal contract form for the transit industry resources -> Request for Proposal [insert date] resources -> The University of York 13th 16th April 2004 resources -> Biological and Biomedical Sciences Program Community Education Initiative resources -> Region III standing regional response team (rrt) meeting williamsburg, Virginia Thursday, January 12, 2012 resources -> Efca eastern District and TouchGlobal, the crisis response ministry of efca Download 7.28 Mb. Share with your friends:
|