The Spool and Bearings make a powered winch with PASCO Structures and are utilized in the Motorized Crane kit.
ME-7022 Spool and Bearings
www.pasco.com/products/lab-apparatus/structures/motorized-structures/me-7022
ME-7030 Motorized Crane
www.pasco.com/products/lab-apparatus/structures/motorized-structures/me-7030