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Modeling electric motors using COMSOL Multiphysics involves transitioning from 2D to 3D motor modeling to achieve a more comprehensive evaluation of magnetic fields and end effects. The process begins with extruding a simple 2D motor model into 3D, assigning physics such as magnets, torque calculations, and coils. However, 3D modeling introduces complexity, particularly in meshing, where a finer mesh is required for convergence. The use of swept meshing is recommended to manage the number of mesh elements effectively, especially in regions with minimal changes in the physics simulation. In 3D motor modeling, coil geometry analysis becomes crucial, as it checks the reasonability of the coil's geometry, ensuring that current can flow from input to output. This step is necessary before conducting a stationary study. The mixed formulation boundary is another essential aspect, involving both magnetic vector and scalar potentials to solve for a vector potential and a scalar potential formulation. The identity pair, which separates the rotor and stator, requires careful handling to model motor rotation accurately. The topology rule in 3D motor modeling dictates that scalar potential domains must be simply connected, avoiding configurations where a vector potential domain pierces through a scalar potential domain. This rule ensures model convergence and can be managed by adjusting the vector potential region or using padding of scalar potential around vector potential domains. The use of gauge fixing for both A fields and scalar potentials is recommended to improve convergence and define the fields uniquely. Sector modeling is advised in 3D simulations to reduce unnecessary mesh elements and simulation time, given the increased degrees of freedom compared to 2D simulations. Adjusting solver tolerances can also facilitate a quicker convergence, providing a preliminary understanding of torque ripple, induced currents, and other parameters before refining the mesh and tightening tolerances for detailed analysis. The use of magnetic flux conservation allows handling of non-linear material properties, further enhancing the modeling capabilities. Overall, 3D motor modeling with COMSOL Multiphysics demands careful consideration of meshing techniques, potential formulations, and solver settings to achieve accurate and efficient simulations. Starting with simpler models from the application library is recommended to build a foundational understanding before tackling more complex configurations.