We decided to begin prototyping in SolidWorks with a fourbar mechanism that would give us the motion we wanted to relocate a reversing wheelchair onto a curb. The aim was to have the mechanism vertically elevate and horizontally translate a wheelchair in a continuous, smooth manner. Because we anticipated that the wheelchair user would operate the mechanism most conveniently with the wheel, the fourbar mechanism was designed so that the crank or input link would have full rotational movement, i.e. a Class I Grashof linkage. Taking into account approximate locations and dimensions of the parts of a wheelchair, the relevant linkage lengths were varied until the desired motion was captured. The CAD concept drawings are shown below
This project had two main prototypes prior to our final presented prototype. Images and a video of the first prototype are shown below.
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Part | Price | Quantity | Notes | Status |
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8 mm retention rings | 20 | From Slider-crank mechanism | Ordered; Received | |
8x16x5 mm bearings | 20 | From Slider-crank mechanism | Ordered; Received | |
Aluminum plate stock (12” x 12” x ¼” plate stock) | $30.51 | 1 | 8975K142 (McMaster-Carr Part No.) | Ordered; Not Received |
Aluminum stock (¼” x 1” x 48” bar stock for links) | $12.28 | 1 | 8975K596 (McMaster-Carr Part No.) | Ordered; Received |
Rotary shaft 200 mm x 8 mm | 2 | From Slider-crank mechanism | Ordered; Received | |
Rubber lining (1” x 18”) | $6.47 | 1 | 9023K82 (MacMaster-Carr Part No.) | Ordered; Received |
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