1. Hammering method
First, clamp one end of the slender rod with three claws for about 10mm, and support one end with the top. Rotate the work at a lower speed, and stop after drawing the high point of the workpiece with chalk. Take a concave iron block in your left hand to make the concave side lean against the opposite side of the high point of the workpiece, and hit the high point of the workpiece with a hammer in your right hand. The impact force is directly proportional to the bending of the workpiece. After repeating this several times, the workpiece is straightened. This method is applicable to the thin and long rod.
2. Lever press method
After the slender rod is installed on the lathe, drive to rotate the workpiece, put a 300mm long wooden stick on the middle carriage and the square knife table, shake the middle carriage, and make the wooden stick press towards the bending part of the workpiece. Continue to move the middle carriage and follow up the tailstock center to prevent the workpiece from falling out. After the workpiece continues to rotate for a few seconds, slowly withdraw the middle carriage and loosen the tailstock center appropriately, depending on whether the workpiece is aligned. If it is still bent, continue with the above method until it is straightened. This method is more suitable for short workpieces.
3. Counterattack method
When the slender rod is long and relatively large, drill the center holes at both ends first, and jack it up with the spindle center and lathe tailstock center. Then rotate the workpiece by hand, find out the high point on the workpiece, and mark it with chalk. At this time, use an iron block about 25mm thick and 40mm wide, which is wider and longer than the large guide rail of the lathe, or a relatively large wood block, and place it horizontally on the large guide rail. Put a screw jack with a head not 60 ° pointed but V-shaped or concave arc on it, support it at the high point of the workpiece bending, and support it with a little force. Hold the workpiece with your left hand, and hit the bending place of the workpiece with the round head of the hammer with your right hand. The number and strength of blows and the length of the workpiece are directly proportional to the size of the bending. The workpiece straightened in this way is not easy to restore bending.