I did an exercise last year where I described how to make a design in Blender. I’ll do it again for gyro fidget spinners.

Create three spheres with appropriate radii for the inner, middle and outer sections. Create two spheres to cut the gaps between the sections. Use like .3mm of clearance. Apply Boolean cuts to the middle and outer spheres.

Create a rectangular prism at z = height/2. Ensure the prism is larger in x/y than the surfaces being cut. Ensure the prism is taller than the largest sphere. Set the origin of the prism to 0,0,0 and mirror it.

Join the spheres to one object, apply a subtractive Boolean to the joined spheres using the rectangular prism. Enter edit mode and separate the spheres by parts.

Create a cone with a radius that equals its height for the bearings. In edit mode, rotate it over the y axis 90 degrees and move it in the x direction to the edge. Ensure the circular base of the cone is still entirely inside the inner portion. Ensure the origin is at 0. Mirror it. Create a union modifier for the inner sphere using the cone as a target. Apply it, select the cones and enter edit mode.

Move the cone .3mm in the x direction. Select the mid, apply a subtractive Boolean using the cones as a target. Move the cones to the edge of the middle poking into the outer, same rule about the base circle. Rotate the cones 90 degrees around the z axis. Apply a union Boolean to the middle using the cones as a target. In edit mode, move the cones .3mm into the outer. Select the outer, apply a subtractive Boolean using the cones as a target.