A combination weighing machine chassis that is comprised of an enclosed hollow support member having an inner surface upon which the drives and controls for the components of the product batch handling units are carried. There are openings formed in the hollow support member that include seals through which the necessary drives and controls extend. As a result, components of the product batch handling units, such as the vibrating trays, chambers and buckets, can be removed for cleaning and the outer surface of the hollow support member can also be cleaned. The operating components are now housed in a closed compartment where they are protected from contamination by air and water borne debris such as oil and food, and the entire weighing machine can now be conveniently washed down and thoroughly cleaned. The vibrator mechanisms for the feeder trays are suspended by extension coil springs from the inner surface of the top portion of the enclosed hollow support member. This provides an improved mounting arrangement for the vibrator mechanism and diminishes the vibrations that are imparted to the other components of the weighing machine.