Design Criteria
- The cleaning device must clean the lens leaving it free of smudges or dust/ dirt particles.
- The cleaning device must not scratch the eyeglasses.
- The cleaning device must be easily transported.
- The cleaning device must weigh no more than 1 lbs.
- The cleaning device must not take more than 60 seconds to completely clean lenses.
- The cleaning device must cost no more than $30.
- The cleaning device must not produce excessive amounts of waste.
- The cleaning device must clean the tight spaces near the hinge and nosepiece.
- The cleaning device must be visually appealing.
- A fresh unscratched lens must first be dirtied to test the cleaning ability of our design. Many things may be used to simulate a soiled lens, but we will be using butter spray for a grease component and a light sprinkle of sand to simulate large more abrasive particles.
- Start a timer and measure how long it takes to clean the lenses. (Criteria 5)
- To examine if the lenses were cleaned properly, shine a white light through the side of the lens and display them against a black background in a dark room. Any visual smudges or scratches mean the device failed. The white light through the side of the lens will make scratches clearly visible. (Criteria 1)
- To determine if microscopic scratches have left the lenses foggy after multiple cleanings, a measure of RGB color values will be used. The closer the color is to true black, the smaller the values will be. This must be compared against a control RGB value with a clean lens against the black background, also with a light through the side. Because the light traveling through the side of the lens will reflect out of the microscopic scratches, the combined effect is that the dark background seen through the lens is lighter. Therefore, after many cleanings with our device we hope to see the color through the lens remain consistent. A camera will be set up with exposure and focus to remain constant. Photographs of the lens can be analysed via software to pick color RGB color values from an image. We will be averaging the values of 9 points across the image (more points makes for a more accurate average color value) (Criteria 2)
- A measure of portability will be obtained by measuring mass and volume. (Criteria 3 & 4)
- Compare weight of any waste produced to the weight of the cleaning device. (Criteria 7)
- The devices ability to clean tight spaces of the glasses will be examined visually. Can the device reach in between the hinges and under the nosepiece? (Criteria 8)
- The cleaning devices' visual appeal can only be measured through stakeholder feedback. A small survey must be conducted. This survey will also include a portability feedback section. (Criteria 9)
- Spray nozzle: $0.69 a piece
- Brush: previously owned
- Microfiber Cloth: 6"x 7" squares owned by group member
- Gasket: previously owned by group member
- ABS Plastic Print: school provided plastic and printer
The cost of all materials vary as per the amount needed. Most of the cost would be set-up costs for manufacturing, so the per-unit cost would decrease as the number of units increased. >1000 units would have a very low cost per unit as opposed to <100 or even <10 units. The spray nozzle is a set per-unit price, with the price decreasing as units increase. The prototype had a spray nozzle that cost 69¢ a piece. The brush can be ordered in smaller quantities from Amazon, sub-1000. The price comes out to just over 18¢ a piece. The microfiber cloth was cut from a regular sized square, into one inch squares. At a 6"x 7" sized cloth, at 8 per pack, our per-unit cost comes to just over 4¢. The rubber gasket comes in packages of 40, costing 7¢ a piece. The plastic is trickier to find an exact cost, but a kilogram of ABS plastic comes to $19.99 a spool. At the weight of all the 3D parts we printed at approximately 1oz, the total plastic cost comes to 57¢ per unit. With all of our materials, the total cost of each unit comes to $1.55. This accomplishes our cost criteria, falling much under our goal of sub-$30. (Criteria 6)
Unit Cost
- Spray nozzle: $0.69
- Brush: previously owned; 50 pcs = $8.99 / 50pcs $0.18
- Microfiber Cloth: 6"x 7" squares, 42in2 per cloth, 252in2 per pack, $8.99 per pack $0.04 (per in2)
- Gasket: 40 pcs = $2.90 $0.07
- ABS Plastic Print: 1kg 1.75mm plastic = $19.99 per spool $0.57 per print
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Total: $1.55