our product

Wheelchase is developing a lever arm wheelchair driver to meet the unique needs of patients in the developing world.

Product Description

Studies show that lever arm wheelchair propulsion is ergonomically superior to conventional pushrim-based propulsion. Commercially available options for lever arm drivers are expensive and use highly specialized parts unsuitable for use in developing nations. Wheelchase, in association with the Free Wheelchair Mission, aims to manufacture a low cost lever arm wheelchair driver that utilizes economical and universally available parts to maximize lifetime and repairability in underserved areas.

Wheelchase’s innovative cable-pulley system is a modular design solution to this issue: our prototype uses common parts such as PVC pipe, steel braided cable, and evaporative cooler pulleys. These are interchangeable and can be replaced with user-sourced materials. Ultimately, this project will give the gift of mobility to developing countries throughout the world.

Design

Concept behind

WheelChase achieves the balance between mechanical advantage (the easiness of propelling) and travel distance, which helps the users move easier, faster without excessively repetitive motions of shoulder joints.

Goals

  • Easy to mount: less than 20 minutes to assemble
  • Easy maneuverability
  • Fits through equal or less than 30 inches doorway : thin parts
  • Long lasting: used bearing for joint and chose materials that last 3-5 years

Solidworks Model

Dimensions and Stimulation

Prototypes

First Build

We built the first prototype using 3D printed parts.

Redesign bearing and lever arm

Test, revise the bearing connector and lower lever arm’s height for better control and efficiency. 

Stimulation studies for different materials

PVC Lever Arm Analysis with 100 N applied force and true deformation
Alloy Steel Lever Arm Analysis with 100 N applied force and true deformation

Future plans

  • Continue with qualification tests.
  • Change materials of the plate and lever arms.
  • Make the lever arms adjustable for various groups of users.