TECHNICAL SUPPORT
Published 2026-03-20
Have you ever encountered this situation - you bought aservowith great joy, only to find that it cannot turn at the angle you want after installing it? Either it can only turn half a circle, or it can turn endlessly and is completely uncontrollable. In fact, this is all caused bythe steering angle range. Today we will talk about this topic to help you thoroughly understand how many degrees theservocan turn and how to choose the one that is suitable for your project.
To put it simply, the steering angle range of the steering gear is like the angle of human joint movement, which determines how many turns it can make. For example, if you bend your elbow, it can probably bend to 150 degrees. The servo also has its own "joint movement limit", which is expressed in degrees as its turning angle range. This value usually ranges from a few dozen degrees to 360 degrees, and the difference between different models is quite large.
Understanding this parameter is particularly important for your project. If your robot needs to accurately control the robotic arm to grab things, choosing the wrong angle range may not even be able to pick up the cup. If you are building a smart car and the turning range is not appropriate, the turning radius may be ridiculously large, making it unusable. So explaining this concept clearly can save you a lot of time.
There are two most common servos on the market, one is 180 degrees and the other is 360 degrees. The 180-degree servo is mainly used in scenes that require precise positioning, such as robot joints and camera pan/tilts. It can stop at any angle between 0 and 180 degrees. The 360-degree steering gear can actually rotate continuously and is more like a small motor, which is suitable for controlling wheel rotation.
The reason why these standards exist is due to the internal structure of the steering gear. There is a potentiometer inside the ordinary servo, which feedbacks the current position like a volume knob, so the angle can be controlled accurately. The 360-degree servo changes the potentiometer to a fixed resistance, which is equivalent to telling the control system "I have been turning", so it becomes a continuous rotation mode.
You can think of the 180-degree servo as a dial with a scale. Whether you want to turn it to 45 degrees, 90 degrees or 135 degrees, it can be accurate. There is a feedback mechanism inside this kind of steering gear. It always knows where it is turning, just like you can feel how high your arm is when you close your eyes. Suitable for use where positioning is required, such as controlling the rudder and adjusting the camera angle.
The 360-degree servo is more like an ordinary motor. You can only control the speed and direction of its rotation, but you don't know where it turns. For example, if you want it to stop at a certain angle, it can't do it. This kind of steering gear is suitable for tasks such as driving trolley wheels and controlling winches to retract and unwind ropes. It only requires rotation speed and direction, and does not require precise positioning.
If you want to change the steering angle range, there are two ways to go. One is hard modification, which is to disassemble the servo, grind off the plastic bumps inside the limiter, or adjust the position of the potentiometer. This method is quite risky. If you are not careful, you may break the gear or short-circuit the circuit board, and the warranty will definitely be lost. It is not recommended for novices to try.
The other is soft modification, which controls the corner range through program settings. Most of today's digital servos support programming. You can limit the range of motion of the servos by adjusting the pulse width of the PWM signal. For example, originally 500 to 2500 microseconds corresponds to 0 to 180 degrees. If you change it to 600 to 2400 microseconds, the angle will become about 20 to 160 degrees, which is simple and safe.
It's not complicated in practice. For example, when you use the Servo library, you can directly write the angle through the write() function, and the bottom layer will automatically generate the corresponding PWM signal. If you want to finely control the turning angle range, you can use the () function to specify the minimum and maximum pulse width, such as servo. (9, 600, 2400), which reduces the turning angle range.
I would like to remind you here that the setting of the rotation angle range must not exceed the mechanical limit of the servo. For example, the servo can only rotate 180 degrees. If you have to let it rotate 200 degrees, the motor will push hard against the limit block, which may cause severe heat generation, or it may directly sweep the teeth and be scrapped. It is best to check the data manual of the servo first to know where its real limit is. It is safer to leave some margin.
When working on a project, it is really a headache to find that the servo angle is not enough. One solution is to add a gear set to enlarge the angle range through the transmission ratio, but be aware that this will reduce the torque and the power may not be enough. Another method is to directly change to a servo with a larger turning angle, such as a special model from 180 degrees to 270 degrees, but the price is usually more expensive.
It is recommended to leave a 20% margin when selecting a model, so as not to use it just to the limit. For example, if you actually need a 150-degree turning angle, it is best to choose a servo that can reach 180 degrees. Read the data manual of the servo. Don’t just listen to what the merchants say. Some marked 180 degrees may actually only be 170 degrees. Knowing this in advance can avoid detours.
Have you ever encountered pitfalls in the steering wheel angle while working on a project? Welcome to share your experiences in the comment area, and let’s avoid pitfalls together! Don't forget to like and save if you find it useful.
Update Time：2026-03-20
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