This paper proposes the design and 3D printing of a compact omnidirectional wheel
optimized to create a small series of three-wheeled omnidirectional mobile robots. The omnidirectional
wheel proposed is based on the use of free-rotating passive wheels aligned transversally to the center
of the main wheel and with a constant separation gap. This paper compares a three inner-passive
wheels design based on mass-produced parts and 3D printed elements. The inner passive wheel that
better combines weight, cost, and friction is implemented with a metallic ball bearing fitted inside a
3D printed U-grooved ring that holds a soft toric joint. The proposed design has been implemented
using acrylonitrile butadiene styrene (ABS) and tough polylactic acid (PLA) as 3D printing materials
in order to empirically compare the deformation of the weakest parts of the mechanical design.
The conclusion is that the most critical parts of the omnidirectional wheel are less prone to deformation
and show better mechanical properties if they are printed horizontally (with the axes that hold the
passive wheels oriented parallel to the build surface), with an infill density of 100% and using tough
PLA rather than ABS as a 3D printing material
