Senior Capstone Project

For my senior capstone project, two of my friends and I decided to desing a wheelchair that would assist patients with sitting and standing up. There many different types of wheelchairs available such as reclining ones, power wheelchairs, etc. We have found some power wheelchairs that can tilt, move with a joystick, and recline. The only issue is the high pricing. Our goal is to try and keep the price down, and focus on the aspect of getting in and out of a wheelchair.

From my personal experience with my grandmother, she has a hard time sitting down. She often has trouble due to different seat heights and usually feels pain when landing on various seats. With this in mind, I proposed the idea of having the seat tilt and have a damping system to help guide a patient like her into a seated position. Conversely, my friends suggested the idea to create a mechanism to help patients out of a wheelchair, which is where the linear actuator comes in to slowly guide them up.

Project Timeline

At the beginning of the semester, we created the Gantt Chart on the right to outline how the workflow would be moving on. We were on schedule for the most part; the only major changes would be starting CAD modeling earlier and delays pushing the FEA later in the semester.

As part of our presentation, we had planned to assemble a prototype with a simplified design to display the proof of concept while keeping the cost lower than it would normally be. We had applied for funding to NJIT's Mechanical Engineering Department with a bill of materials of a damper, linear actuator, and typical wood and relevant fasteners. However, the parts failed to arrive in time, but the proposed prototype is shown on the left.

Bill of Materials

On the right, there is a screenshot of our bill of materials. To design for assembly, most of the parts used are standardized, allowing for easy replacements and procuring if necessary. The frame would be custom made, while a slab of steel would be used for the base and base mounts. Aside from the parts and materials, an estimated $1400 was added on to account for labor, services, and other expenses. If there was more time in the semester, more attention and calculation would be needed for the cost analysis, to keep the product as simple, safe, and cheap as possible.

As per our design objectives, the wheelchair should not corrode if used in inclement weather. With this in mind, typical wheelchair materials, such as 6061-T6 aluminum was used. For the steel components, they will be coated to increase corrosive resistance.