Long low profile vibratory tubs are normally used for long narrow parts or have compartments to prevent part on part hitting during the process. The operator typically moves along the compartments loading and unloading. Load heights are critical for the ease of operator involvement. Deep profile tubs are used for larger parts. A part should be no larger than two thirds of the width of the tub in order to rotate freely. Tub machines are also used to self tumble part on part and a variety of doors are available for unloading.
An important consideration is the load height of the tub. Ideally one wants the lowest possible load height consistent with unloading into a bin.