Illustrations Of Common Steering Gear Faults And Treatment Methods, Repair Of Steering Gear That Does Not Rotate And Jitters

Friends who play withservos, do you often encounter situations where theservos don’t turn, vibrate or simply “go on strike”? Don’t worry, these problems are actually very common. Today, I will combine my many years of experience and use the most down-to-earth way to take you through the "difficult diseases" of the steering gear from head to toe. By the way, I will also attach a super practical "treatment" diagram to ensure that you have an idea after reading it.

Why doesn't the steering gear move?

Theservohas no response after being powered on. This is the most troublesome problem. First you have to check whether the power cord is connected correctly. The servo usually has three wires: positive, negative and signal wires. Many novices will reverse the positive and negative poles, causing the servo to "bored" directly. In addition, insufficient power supply is also a common cause, especially when you use the development board to directly supply power, the current is too small to drive the servo.

If it is confirmed that there is no problem with the wiring and power supply, it may be a problem with the signal line. Check whether your control pin sends out the PWM signal correctly. You can try changing the pin, or use an oscilloscope to see if the waveform is normal. Sometimes the servo angle is set beyond the limit value in the code, and the servo naturally cannot respond.

How to solve the problem of servo vibration

The servo is vibrating like a pendulum when running. This is probably caused by the power ripple being too large. The current at the moment when the servo is started is very large. If the power supply quality is not good, the voltage will fluctuate violently, causing the control chip to misjudge. The solution is very simple. Connect a large capacitor in parallel to both ends of the power supply, such as an electrolytic capacitor of more than 470 microfarads, to effectively filter out ripple.

Another reason that is easily overlooked is signal interference. If your servo cable is too long or shares a power supply with other high-power devices, it may be susceptible to interference. You can try using shielded wires for the signal wires, or provide separate power supply to the servo. Also check whether the servo swing arm is stuck. Excessive mechanical resistance will also cause the servo to vibrate due to repeated position adjustments.

How to calibrate the servo neutral position

If the center position of the servo is inaccurate, it will cause your robot to walk crookedly. Calibrating the neutral position is actually not difficult. You need to remove the servo swing arm first, and then send a PWM signal to turn the servo to 90 degrees. Then put the swing arm back and try to make it perpendicular to the servo housing, so that the basic neutral position is set.

If you're looking for more precise control, try using program fine-tuning. Many servo libraries have the function of setting the center offset. Through continuous testing, you can find the PWM value that makes the mechanical structure completely centered. Remember to write this offset value into the code so that you don’t have to recalibrate it every time you start it. After calibration, use a marker to mark the servo and swing arm to facilitate future inspection.

Is it normal for the steering gear to be seriously overheated?

If the servo is hot to the touch, it is definitely not normal. The servo will be a little warm when it is working normally, but if it is too hot to touch, it is usually overloaded. Check whether your mechanical structure is too tight, or the torque selected by the servo is not enough. Long-term overload operation will definitely cause heat. Changing a servo with a larger torque, or optimizing the mechanical structure to reduce resistance is the fundamental solution.

Poor cooling can also cause overheating. If the servo is installed in a closed space or works continuously at high intensity, heat will accumulate without being able to dissipate. You can leave some ventilation gaps during installation, or add a small heat sink to the servo. Another thing to note is that improper PWM frequency setting will also cause the internal driver chip of the servo to heat up. Check the recommended frequency of the servo you are using.

What's wrong with the slow response of the steering gear?

I sent a command to the servo, but it took a long time to move. This is often because the control signal update frequency is too low. Reduce unnecessary delays in the code and update the PWM signal in a more timely manner. Also, your program logic may be too complex for the microcontroller to handle. It would be much better to optimize the code structure.

Mechanical reasons cannot be ignored either. If dust enters the steering gear gear or the grease dries out, it will increase the rotational resistance. You can disassemble the servo, clean the gears, and re-apply special grease. If the servo has been used for a long time, the internal potentiometer may be worn. In this case, it would be more cost-effective to replace the servo with a new one.

How to prevent steering gear teeth from sweeping

If you hear an abnormal "clicking" sound from inside the servo, it's probably because the gears are slipping or sweeping. This problem is mainly caused by external impact, such as the servo being violently impacted when the robot falls. Adding buffer protection during installation, or setting soft start and soft stop in the program to make the servo accelerate and decelerate more smoothly can effectively protect the gears.

During use, be careful not to leave the servo in a stalled state for a long time. When the steering gear is turned to the extreme position and is forcibly blocked by an external force, the gear is subject to the greatest force. When designing the mechanical structure, mechanical limits should be installed to prevent the steering gear from exceeding the movement range. Regularly check whether the steering gear mounting screws are loose. A loose structure will cause poor gear meshing and accelerate wear.

Okay, that’s all for today on the frequently asked questions about servos. What other weird failures have you encountered in actual use? Or which of the above issues gives you the biggest headache? Welcome to share your experience in the comment area. Only by communicating together can we make progress faster. If you find the article useful, don’t forget to like it and share it with more friends who play servos!