The next time you're looking for a new or used mixer, consider how the capacity, parts, and service agreement meet your mixing needs. MIXING CAPACITY Mixers range in mixing capacity from 4 to 16 cubic feet. Unfortunately, many manufacturers are not following the same procedure to rate the capacities of their units. It is virtually impossible for contractors to accurately compare mixers made by different manufacturers. DRUM Check the steel thickness of both the drum shell and the drum end. Thick drums withstand more abuse and more wear than thin drums. PADDLES Paddles are available with neoprene or steel blades. The size and pitch of the paddles also are important. SHAFT BEARINGS Paddle shaft bearings probably require the most maintenance on a mortar mixer, next to the gasoline engine. Replacing them also is one of the most expensive repairs to have to make. SUSPENSION If you plan to tow your mixer, especially on interstate highways, check the axle carefully. ENGINE Jobsite conditions determine which is better, a gasoline engine or electric motor. POWER TRANSFER Three types of power trains are available on mixers (from the least to the most expensive): open gear and belt drive; enclosed gearbox drive; or hydraulic drive.