There are three methods to prevent crane boom excessive swinging. The first method is to replace the crane boom and minor axis. But due to economic conditions, most enterprises can not adopt this method. The second method is to re-processing arm holes and minor axis. Two ways to remove the arm shaft hole rework. One is using Keng bed or Special key bed do expanded repair to old shaft hole on the boom when conditions permitting. The second way is to use a dedicated manual cutters to shape the shaft hole repair. At the same time deal with the turntable shaft hole corresponding increase repair it and boom hole consistent. Then, the processing of new minor under the new aperture size. In practice, these two processing methods have been used before.
The first way requires good mechanical processing equipment while the second way requires Maintainer with higher level of technology and experience. Another thing need to note is the repair processing of volume aperture should generally be 1.5mm to 2mm, too large size will affect strength of crane boom. The third method is to manufacture new minor axis and weld on both sides of the arm hole plus washer.