We design a device employing a couple of star-gearing mechanisms attached to both sides of a wheelchair to climb and descend stairs mainly but also other obstacles, giving independence and mobility to the user. The star system proportions high maneuverability and stability under several functionality conditions. The kinematical analyses use Lagrange formulation, employed to study the star-system performance over a rough plane and ascending and descending stairs. We illustrate the viability of the design performing the stability studies during the ascent or descent of stair.