A balanced planetary gearbox including an assembly having an input stage and an output stage. The assembly includes two grounds, each with ground rollers and ground rings. The two grounds are fixedly attached to one another. The assembly includes a sun gear and planet sub-assemblies between the two grounds. The planet sub-assemblies include at least one input planet gear and one output planet gear. The sun gear and the input planet gears include rollers. An abutment of rollers in the gearbox keeps the sun gear and the planet gears in alignment. The output gear meshes with an output ring disposed in between the two ground rings, such that a combination of the at least one input planet gears from each of the plurality of planet sub-assemblies provides a structural symmetry to the planetary gearbox.
