The present invention may be embodied as a compounding system having a chamber assembly defining a working chamber; a shaft, a sleeve assembly, and a plurality of arms. The sleeve assembly has first and second sleeve members each defining at least one arm opening and adapted to be arranged in a first configuration in which the first and second sleeve members are detached from each other and a second configuration in which the first and second sleeve members are secured together around the shaft to support the sleeve assembly on the shaft. Each of the arms is configured to be inserted partly through one of the arm openings when the sleeve assembly is in the first configuration and held in a desired configuration relative to one of the first and second sleeve members when the sleeve assembly is in the second configuration.