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  2015 Hua Fei CNC company dinner

• How to choose a suitable welding positioner?

• How to maintain the welding positioner?

• Rescue measures for CNC cutting machine with large cutting error

• How to protect a welding positioner?

• How to purchase a good welding positioner?

• Maintenance method of special welding chuck for positioner

• How much do you know about the classification of the welding rotators?

• Structure Types of Welding positioners

• The 8 principles for choosing a welding positioner

• Common fault problems and solutions of welding positioner

The stepper motor is a device with discrete motion, which has an essential relationship with modern digital control technology. When the stepper motor works at a low speed, damping technology should generally be used to overcome the low-frequency vibration phenomenon, like adding a damper to the motor or using a subdivision technology on the driver. The current digital control system of plasma CNC cutting machines in China, the application of stepper motors is very extensive.

With the emergence of all-digital AC servo systems, AC servo motors also increasingly used in digital control systems. The AC servo drive system is closed-loop control. The drive can directly sample the feedback signal of the motor encoder. The position loop and speed loop are internally formed. Generally, the stepping motor will not lose steps or overshoot, and the control function is more reliable. The maximum torque is three times the rated torque, which can be used to overcome the moment of inertia of the inertial load at the moment of starting.

Different moment frequency characteristics

The output torque of the stepper motor decreases with the speed increase and will drop sharply at a higher speed, so its maximum working speed is generally 300~600RPM. The AC servo motor is a constant torque output, which is at its rated speed (generally 2000RPM or 3000RPM), can output the rated torque, and the constant power output is above the rated speed. Compared with the portable and cantilever CNC cutting machine, the gantry CNC cutting machine is more chaotic.

Different overload capacity

Stepper motors generally do not have overload capability.　　

Different running function

The stepper motor control is an open-loop control. When the starting frequency is too high, or the load is too large, it is easy to lose steps or stall. When the speed is too high, it will easily overshoot, so to ensure its control accuracy, it Should deal with rising and falling speed issues. The AC servo system has a resonance control function, which can cover the machine's insufficient rigidity, and the system has a frequency analysis, and performance (FFT), which can detect the resonance point of the machine, which is convenient for system adjustment. Take the Panasonic AC servo system as an example, it can speed overload and torque overload.

Different low-frequency characteristics

Stepper motors are prone to low-frequency vibration at low speeds. The AC servo motor runs very smoothly and does not cause vibration even at low speeds.

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