1 Step, 2 Step: A moveable wheelchair ramp

Developers: Kailani Montane and Darshana Jaint

Advisors: Brandi McDaniel and Sarah Hartsock

Supervising Professor:  Kevin Caves


Our client owns a home which is not wheelchair accessible, preventing people with wheelchairs from easily and safely entering the house. However, they did not want to build a permanent ramp which would use up the entirety of the space available in their carport since ADA standards require ramps to have a length of 12 in. for every inch of incline. The main goal of this project was to create a ramp that can be easily moved out of the way when not in use, and will allow a home to become safely accessible for people who use wheelchairs. The three key features of the device are that the user can get into and out of the house safely and stably; that the device is easy for staff to set up, use, and stow when done; and that the ramp part of the device does not take up too much space in its open and closed positions. This was accomplished by creating a retractable ramp that is attached to a barn-door mechanism which allows the ramp to slide into and out of place. Testing with a test subject who uses a wheelchair proved the device effective and easy to use. The device is expected to be crucial for anyone who uses a wheelchair and wants to enter a house that is not accessible. The device can be easily stowed, and will not interfere with the spatial demands of a household, but can also be extended to use as a safe, reliable, and accessible ramp for visitors and residents who use wheelchairs.


Introduction and Background

Our client is Residential Services, Inc. (RSI), an organization that provides living options and support for people with intellectual and developmental disabilities. They have a non-accessible home that needs to become accessible. Our test subject, Mr. T, is a middle-aged man with cerebral palsy. Cerebral palsy is a permanent neurological disorder which may affect movement, muscle control and coordination, motor skills, and oral motor function [1]. Mr. T uses an electric wheelchair to move, and communicates using a word board and hand gestures. Mr. T would like to visit his friends who live in the RSI home, though it is not currently wheelchair accessible. The only way for Mr. T to get inside is to be carried in. Once inside, he does not have access to his wheelchair, since it is too heavy to be carried in, and must sit in one location for the entirety of his visit. This process takes away his independence.

There are many ramps available on the market that seemingly address the problem. A permanent, wheelchair accessible ramp cannot be built around the friends’ house because the residents do not want a permanent ramp installed, since the ramp would only be in use when Mr. T goes to visit. The residents also want to leave the space in the carport free, and a ramp that adheres to the Americans with Disabilities Act (ADA) regulations of 12 in. of ramp per 1 in. of incline would use up the available space [2]. Portable ramps can be unsafe and unstable as there is nothing holding the ramp in place, and can have extremely large incline angles due to their short length [3, 4]. The ramp that Mr. T currently uses has an incline angle of 13˚, and he needs to climb a height of 18.5 in.


Project Goals

The goal of this project was to create a ramp that can be easily moved out of the way and will allow our client’s home to become safely accessible to people, such as our test subject Mr. T, who use wheelchairs. The three main features of the device are that the user can get into and out of the house safely and stably, that the device is easy for staff to set up, use, and stow when done, and that device does not take up a lot of space, either when in use, or when stowed.


Design and Development

Our design consists of 3 main assemblies: the ramp (fig. 1), the winch set-up (fig. 1), and the sliding barn-door mechanism (fig. 2). The device will remain at the side of the door when not in use. All figures can be found in appendix F.


  • The Ramp Assembly: The ramp assembly allows the user to get up and down the ramp easily and safely and is made of pressure treated plywood to withstand the weight of the user.
    1. Ramp: The ramp consists of two pieces of 3’ x 4’ x 23/32” pressure treated plywood and is 8 feet long in total (fig. 3). The angle of incline is approximately 11 degrees which is smaller than the current angle the test subject uses to enter his transport vehicle. The pressure-treated wood was chosen to withstand the outdoor weather conditions that the device may encounter because it will be kept in the carport outside of the home.
    2. Side Panels: The ramp has four 2”x4”x4’ pressure treated side panels that are secured onto the edges of the ramp (fig. 3). These side panels provide strength for the outer edges of the ramp. They also are a safe-guard to ensure that the user does not roll off the ramp. These safeguards were a key component that the test subject and his assistant expressed a need for.
    3. Supports: The device has four supports (fig. 3). All four pieces are made of pressure treated plywood. The two short supports are permanently attached to the top portion of the ramp. These two supports rest on the top step when the ramp is fully opened. The other two long supports are located closer to the floor and are rotary supports. They are attached using bolts allowing the user to easily rotate them in and out of the way. The four supports remove some of the stress on the barn-door mechanism and allow for extra safety for the user.
    4. Spring Hinges: The two pressure treated boards are attached by 4 spring hinges (fig. 4). These spring hinges allow for the ramp to easily open and close. The pressure treated plywood is heavy so the springs allow the user to easily open the ramp when it is lowered by relieving tension.
    5. Wheels: The ramp has two wheels located at the end of it (fig. 5). The wheels allow the user to easily slide the ramp down when it is being lowered with the winch. The wheels can then be moved out of the way by kicking the wooden part up. This will cause the wheel to move up and off the ground. When lifting the ramp back up, the user will simply kick the wooden part down so that the wheels touch the floor.
    6. Lip: The ramp contains two hooks (fig. 6) that allows for a smooth transition from the ramp to the inside of the house (fig. 7). The hooks secure the ramp to the door frame and allow the edge of the ramp to perfectly align with the lip of the door frame.


  • The Winch Set-Up: The winch set-up is used to easily lift and lower the ramp using minimal force using a system consisting of a winch, pulleys and cables.
    1. Winch: The winch allows the user to manually move the ramp up and down. It can hold the weight of the ramp with a factor of safety of 10 (fig. 8). The user moves the ramp up by rotating the handle clockwise. To move the ramp down, the user must lift the metal stopper and then rotate the handle counter-clockwise. The winch must not be rotated all the way up. The cable has a blue marker indicating when to stop raising the device and a red marker showing when to stop lowering the device.
    2. Pulley and Cable Assembly: The winch has a metal cable that is attached to a stationary and swivel pulley. They are attached to a carabiner, lag eye screw and a 2”x6”x3’ pressure treated plywood piece (fig. 9). The cable comes down to another hook and carabiner which are attached to a chain that pulls the ramp up from the center (fig. 10). To remove the chain, the user must simply unhook the metal hook from the lag eye screw and move the chain to the side and off the ramp. This set-up is used to easily lift and lower the ramp using minimal force.


  • The Barn-Door Mechanism: The Barn-Door Mechanism serves two functions: it allows the user to move the ramp in front and to the side of the door so that the ramp doesn’t take up too much space in the garage and so that it is easy to move with minimal force.
    1. Barn-Door Piece: The barn-door piece (fig. 11) is a very important part of this device. The piece attaches to the metal L brackets and the ramp. It allows the user to move the ramp in front of the door and to the side of the door. The wheels allow for easy movement and the metal bar is 8 feet long giving the user a lot of space to keep the device out of harm’s way. The piece also is simple to use and allows the user to apply less force to move the device.
    2. Plastic Barn-Door Attachments: To keep the barn door piece from coming off the wall, we created plastic pieces to attach below the wheels of the barn-door piece (fig. 12). These were machined to fit perfectly onto the barn door piece and do not allow the wheels to come off the long black metal bar. This is a vital component for the safety of the user.
    3. Metal L-brackets: The metal L-brackets were chosen due to their strength and versatility (fig. 12). They provide an easy way to attach the barn door piece to the ramp. Their multiple holes also allowed for easy attachments of other components (winch, pulley and cable assembly, barn-door piece, etc.). The purpose of this piece was to allow for easy attachments.
    4. Latches: Although the ramp is safely in place using only the winch, we added two latches for additional safety (fig. 13). These latches allow the ramp to be securely set up in an upright position on the L-brackets.
    5. Wooden Swinging Back-Bar: The wooden swinging back-bar (fig. 14) keeps the ramp from digging into the doorframe and rest it in front of the door. It is held up using a latch when it is not in use. When it is in use, it is held up to the proper height by another wooden piece attached to the walls surrounding the door frame.



The device was tested against all of our design criteria. In particular, the device was checked to see if it could support the weight of the test subject and his wheelchair (290 lbs. with a factor of safety of 2), was weatherproof, and had a safe incline from the floor to the top of the stairs (<13˚), fit within the 14 ft. x 18.5 ft. carport when fully extended, allows the test subject to fit within the ramp (ramp width of ≥30 in.), and be safely opened in a controlled manner. Furthermore, the device was checked to see if it could be set up and taken down quickly and easily (<10 min. for each), fit within the space next to door of 60 in. x 19.5 in. x 107 in., is safely mounted on wall when and when not in use, keeps test subject stable, allows test subject to easily get on and off ramp, and allows test subject to fit through door. Each of these criteria were chosen to ensure the safety and stability of the test subject, primarily, as well as the safety of the assistant. The criteria were also chosen to test the device for ease of use, retractability and stowability, usefulness, and durability. Tests were performed both in lab as well as with the test subject to determine whether each criteria was met. Overall, the client, test subject, and assistant all seemed very satisfied with the device (see appendix C for more detailed information).


Discussion and Conclusions

We tested the device with the test subject and his assistant, after internal testing, to determine safety, stability, ease of use, and overall satisfaction with the device. We administered a survey to quantify each of these factors, and the device was rated at a 5 on a 1–5 for each factor (see appendix C). Testing helped us determine that the device functions as intended. In particular, we have been working to create a ramp that can be easily stored out of the way when not in use, and that can be used by people who use wheelchairs to enter and exit our client’s home. We have created and installed a retractable ramp that allows the user to get into and out of the house safely and stably; is easy for staff to set up, use, and stow when done; and doesn’t take up too much space when opened or stowed. Overall, the client, and the test subject and his assistant were all very happy with the delivered device.



We would like to thank our professor, Kevin Caves, for all the help he has provided for us throughout the semester. Thank you to TA, Paul Thompson, our test subject Mr. T, and the assistants and coordinators at RSI for their help and feedback. We’d like to acknowledge the Duke University BME Department for the facilities and resources they’ve provided. Finally, thank you to our families for all their support throughout this process!


Contact Information


Kailani Montane (Duke BME Alumnus)

Phone: (786) 512-3954

Email: kpmontane@gmail.com

Address: 17999 N.E. 17th Ave., North Miami Beach, FL 33162

Darshana Jaint (Duke BME Alumnus)

Phone: (919) 808-7572

Email: jaint.darshana@gmail.com

Address: 250 S. Estes Dr. #63, Chapel Hill, NC 27514



  1. “Cerebral Palsy: Hope through Research”, NINDS, Publication date July 2013. NIH Publication No. 13-159. Retrieved on 22 March, 2017, from https://www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/Hope-Through-Research/Cerebral-Palsy-Hope-Through-Research
  2. “Chapter 4: Ramps and Curb Ramps”. United States Access Board. Retrieved on 8 February, 2017, from
  3. “SUITCASE® Singlefold AS Ramp”. EZ-Access. Retrieved on 8 February, 2017, from https://www.ezaccess.com/products/suitcase-singlefold-as-ramp.
  4. “Track Ramps, Channel Ramps,
    Handi-Ramp Modular Channel Track Ramp System”. Handi-Ramp. Retrieved on 8 February, 2017, from https://www.handiramp.com/trackramps.htm.

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