This study investigates the nonlinear dynamics of traction for an omniwheel mobile robot platform. A nonlinear slip model is incorporated into the dynamics of the system and the resulting equations of motion are derived using Euler-Lagrange formulation. These are additionally transformed into slip-space, where the dynamical equations lend themselves to a convenient analysis of the slip dynamics. The conventional assumptions for ideal rolling are also explored and a reduced expression for the nonlinear dynamics is generated for such situations. Preliminary explorations toward a comprehensive analysis of the dynamics for omniwheel platforms under various control schemes is also initiated.