A small size epicyclic gear system in which the mating between gear housings is purposefully made with some play to allow a certain degree of relative movement to accommodate machining runout errors in the manufacture of the gears. A castellated cap fastened to the motor engages with a castellated gear reduction body. The tolerances built into the cap and gear reduction body allow relative radial movement therebetween to reduce binding of the gears during rotational positions in which the gear component runout tolerances are additive.