TECHNICAL SUPPORT
Published 2026-03-21
Have you ever encountered this situation: watching someone else adjusting theservoparameters in a video, including a bunch of numbers such as angle, speed, and torque, and setting them yourself, only to have theservoeither not move, move randomly, or even burn out? Don’t worry, today we will talk about how to set theservoparameters appropriately. In fact, this matter is not that mysterious. The key is just a few core parameters. If you understand the cooperation between them, you can easily handle it.
There are actually four core parameters of the steering gear: angle range, speed, torque and control method. You can think of a servo as the "joint" of a robot. These parameters determine whether it can turn to the position you want, whether it turns fast, whether it is strong enough, and how you direct it. For example, if you plan to make a small robotic arm, you must be concerned about how heavy an object it can grasp and whether it can accurately stop at a certain angle.
These parameters do not exist in isolation, they influence each other. Just like you have to look at displacement, fuel consumption, and wheelbase when buying a car, you also have to look at these four pieces when choosing a steering gear. If the parameters are set incorrectly, the most common result is that the action is not in place or the response is too slow. In serious cases, the servo will be burned directly. So the first step is to figure out what the servo in your hand can adjust.
The angle range is usually determined by the type of servo. An ordinary servo is generally 0 to 180 degrees, and a continuously rotating servo can rotate infinitely. But many servos allow you to fine-tune the actual range by setting the width of the PWM signal. For example, if you are making a face-following gimbal and want the camera to rotate left and right, setting it to 0 to 180 degrees is enough. But if you are doing steering on an omnidirectional mobile car, you may need continuous rotation mode.
Never push the angle range to the limit as soon as you get started, as this is the most likely operation to burn out the servo. The correct approach is to first check the mechanical limit in the manual, then use the microcontroller or servo controller to give a conservative PWM value, and then slowly expand it to the actual required angle. For example, first set it from 20 degrees to 160 degrees, and then gradually relax it after the test is OK until you find the boundary of stable work.
Speed is generally expressed in "seconds/60 degrees". For example, it turns 60 degrees in 0.1 seconds, which is quite fast. There are two problems with going too fast: first, the movement seems very hasty, and second, the inertial impact may damage the connected mechanical parts. On the other hand, too slow and clumsy. For example, if you are making an automatic window opener, the speed must be moderate. If it is too fast, the window frame will be damaged. If it is too slow, it will take half a day to open the window.
During actual debugging, it is recommended to set a medium speed first, such as 0.2 seconds/60 degrees, and then fine-tune it according to the actual movement effect. Some high-end servos support dynamic speed adjustment in the program, which gives you a lot of flexibility. Remember one key point: speed and torque tend to trade off. The faster you run, the less strength you have. You have to find that balance based on the load and response speed required by the device.
The unit of torque is kg·cm. The simple understanding is: it can lift multiple objects 1 cm away from the axis of the steering gear. You can estimate it this way: If your robotic arm wants to lift a 0.5 kg weight at 5 cm, it requires at least 2.5 kg·cm of torque. But this is only a static situation, and friction and acceleration must be included in the actual situation. Therefore, for the sake of safety, it is best to choose a theoretical value that is 30% to 50% larger than the calculated result.
Many people think that the greater the torque, the better. In fact, this is a pitfall. A servo with too much torque is large, heavy, and expensive, and will also bring additional burden to the mechanical structure. For example, if you are building a lightweight quadruped robot, it would be more appropriate to choose a medium-torque servo that is just enough. If it is too heavy, it will directly affect the motion performance and battery life. Estimate the load, leave a margin, and actually test it. Follow this process to choose the most reliable one.
There are three main control modes: traditional PWM, serial bus control, and analog signal control. PWM is the most versatile and can be driven by almost any microcontroller, but each servo occupies a separate pin. Serial bus control is amazing. One line can connect dozens of servos in series, and it can also read back status information such as angle and temperature. It is especially suitable for multi-server projects such as robotic arms and bionic robots.
Which mode to choose depends on the size and complexity of your project. If you are just doing simple projects with one or two servos, such as gimbals and door locks, PWM mode is enough, and the setup is simple and low-cost. But if you have more than 6 servos in your project, it is strongly recommended to choose a serial bus servo, which can free you from complex wiring and pin assignments. In addition, some bus servos also support real-time adjustment of speed and torque. This function is particularly useful when dynamically changing actions are required.
The steering gear is particularly sensitive to voltage. If the voltage is low, the torque will be insufficient and the movement will be slow. If the voltage is high, it will easily burn the internal circuit. The nominal operating voltage of most servos is 4.8V to 6V, and high-voltage servos can reach 7.4V. However, in actual use, the battery voltage will drop with the power, or drop instantly under heavy load, causing the servo to vibrate and lose control, such as "draught" symptoms.
There are three ways to solve voltage instability: First, use a DC-DC voltage stabilizing module to power the servo independently, and do not share the power supply with the main control board, so as to avoid mutual interference. Second, connect a large capacitor at both ends of the servo power supply, such as about 1000 microfarads, which can buffer the instantaneous large current impact. Third, if you are using an integrated servo with an integrated driver, the voltage has usually been stabilized internally, so just supply power directly at the official recommended voltage. During debugging, use a multimeter to measure the actual voltage at the servo terminal to ensure it is always within a safe range.
What is the most troublesome servo debugging problem you have ever encountered? Welcome to share your experience in the comment area, and don’t forget to like and save it so that more friends can see it!
Update Time：2026-03-21
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