Tennis Tutor ball machines have become one of the nation’s most popular portable tennis trainers. Their convenient size, durable batteries and powerful functionality make them a great addition to any tennis player’s training routine. The only part of owning a Tennis Tutor that can be a bit tricky is learning how to clean one. Wipe dust off of the outside of the ball machine with a moist paper towel. Wet the towel with water only, and don’t use any strong detergents or soaps to clean the machine. Remove tough mud spots or grease stains with a wet washcloth. If you have any trouble removing the dirt with water, then apply a diluted solution of dish soap and water to the washcloth and continue to scrub. Pick out any large pieces of grass, pine straw or bark from the hopper or rotating ball feed mechanism. Unscrew the bottom of the ball hopper from the top of the machine with a Phillips-head screwdriver. Gently detach the wires connected to the ball feed mechanism, and remove the hopper fr