1. After the rolling machine is started, the stepping motor does not shake, which is generally caused by the phase failure of the stepping motor or its control system. It may be the fault of the stepping motor itself or the fault of its drive circuit. First, check whether the connection plug of the stepping motor is in good contact. If the connection plug is in good contact, replace the one phase motor without fault. If the motor operates normally after replacement, it indicates that the original stepping motor is faulty. If the motor still does not work normally after replacement, it indicates that its control part is abnormal. You can focus on checking the high-power triode and the protective element release diode on the drive board. Generally, These two components are more likely to be damaged.

2. During the operation of the rolling machine, the workbench stops suddenly and the stepping motor shakes. This phenomenon is generally caused by mechanical failure, but it may also be caused by the failure of the control system. At this time, the worktable can be returned to the original point and the processing program can be restarted. If the worktable always stops running when it runs to a certain position, it should be caused by damage, deformation or foreign matter jamming of a part of the transmission system. First, cut off the power of the control system, and then turn the lead screw by hand. If you feel that the resistance at a certain position is too great or even can't turn at all, it indicates that there is a fault at this position. Check whether the clearance between the screw nut and the lead screw or the slide plate insert is too tight, whether there are foreign matters in the ball guide groove of the ball lead screw, whether the lead screw is bent or deformed, whether the flexible gear in the stepper motor reducer is loose or whether there are foreign matters stuck, etc. If the manual turning is normal, the control system is faulty, and the inspection shall be carried out according to step 1.

3. The stepper motor operates normally at low speed, and loses step at high speed. This phenomenon may be caused by the reduction of drive power voltage, which reduces the output torque of the stepper motor. Therefore, the drive power supply shall be checked. When the high-voltage opening triode is damaged, the high-voltage power supply cannot be connected, which reduces the output torque of the stepping motor at high speed, causing step loss. It may also be caused by mechanical failure. Therefore, if the inspection of the above components fails, the lead screw, nut, slide plate, stepper motor reducer and other parts should also be inspected. When a component is bent, deformed, or has foreign matters stuck, the running resistance will increase. When it runs at low speed, the phenomenon is not obvious, but when it runs at high speed, the running resistance cannot be completely overcome, causing step loss.

4. At the end of the rolling machine operation, the roller cannot return to the original point, which is generally caused by the control system failure. The winding roll is required to operate at a low speed during feeding or processing. At this time, the stepper motor runs at a low speed and uses low-voltage power supply. When the program returns to zero, it requires rapid return. At this time, the stepper motor runs at a high speed and uses high-voltage drive power supply to increase the output torque and ensure normal return to zero. A switch triode is used to control the output of the high-voltage drive power supply. When the switch triode is damaged and returns to zero at high speed, the high-voltage power supply cannot be switched on, and the output torque of the stepping motor is insufficient, resulting in zero return and step loss, and the roller cannot return to the original point. This fault can be eliminated by replacing the switch triode.

5. At the end of the rolling machine operation, the upper roll is offside when returning to the original point. This phenomenon is generally caused by too much running resistance of the mechanical transmission system. When the plate is fed, the upper roll runs at low speed, driven by low voltage, and the stepping motor has small running torque, which is insufficient to overcome the resistance and cause step loss. When returning to zero, the stepping motor is driven by high voltage, with high running speed, large torque and no hard resistance. The stepping motor operates normally without losing step. In this way, the above phenomenon will be caused by missing steps when leaving and returning normally.