... 3. Delivery on time 4.used on gantry crane,tower crane Function of electric motor cable reel : DJ1D type ... reel drum are usually used on gantry crane,tower crane,and bridge type lifter and the other ... is very good.3, Lock performance.Our machine have worm gear with good lock performance,when ... it should be polished by thin emery cloth or machine polishing .otherwise ,you need change the collector ring ...