A planetary grinding machine having a simple design with a minimal number of parts, which are all easily accessible for maintenance and repair is disclosed. The machine has a rotating planetary disk with rotating screeding disks attached. The planetary disk is driven by a shaft extending through a top housing cover plate, which supports a transmission driven by a motor. As the planetary disk rotates, a single belt engages a stationary gear on the cover plate and pulleys on screeding disk shafts to turn the screeding disks as the planetary disk is turned. The belts and pulleys for the drive mechanism are sandwiched between the planetary disk and the top cover to protect the mechanisms from dust and debris. The bearings are sealed to prevent dust and debris from entering and oil from escaping. The bearings, being on the inside of the planetary disk, keep oil from landing on the floor.