How Does The Servo Rotate 360 degrees? The Modification Method Is Easy To Understand At A Glance

Have you ever encountered this situation: theservoyou bought can only rotate 180 degrees, but your project clearly requires it to rotate continuously? Don't worry, today we will talk about how to achieve 360-degree rotation of theservo, so that theservoin your hand can really "turn".

How to change the steering gear to 360 degrees

If you want to change an ordinary servo to 360-degree rotation, the most direct way is to modify it. You'll need a small screwdriver, a soldering iron, and a little patience. First take apart the servo housing and you will see the circuit board, motor and a set of gears inside. The key step is to find the potentiometer - the small disc connected to the output shaft, which is responsible for detecting the angular position.

After disassembly, first use a screwdriver to cut off the physical limit bump on the output shaft so that the gear can rotate freely. Then carefully solder the potentiometer off the circuit board, or use a multimeter to find its midpoint and secure it. Finally, put all the parts back together, and a 360-degree continuous rotating servo was born. The whole process takes about half an hour, and the success rate is quite high.

What is the difference between 360 degree steering gear and ordinary steering gear?

To put it bluntly, an ordinary servo is an "angle control expert". If you give it a pulse signal of 1.5 milliseconds, it will turn to 90 degrees; if you give it 2 milliseconds, it will turn to 180 degrees. There is a potentiometer inside it to feedback the angle, and it will stop when it reaches the specified position. The 360-degree servo is more like a "speed-regulating motor". You give different pulse widths, and it just controls the speed and direction of rotation.

For example, when you send a 1.5 millisecond pulse to the 360-degree servo, it will stop; if you give it 1.6 milliseconds, it will turn clockwise slowly; if you give it 1.8 milliseconds, it will turn faster. Conversely, given 1.4 milliseconds, it will turn counterclockwise. So it can't tell you which angle you are currently turning to, but it can help you achieve infinite rotation, which is especially suitable for wheels or conveyor belts.

How to write a program for 360-degree rotation of the steering gear

Writing a program to control a 360-degree servo is actually simpler than an ordinary servo because you don't have to calculate the angle. For example, you only need to use theServolibrary and then call the()function. The key parameter is the pulse width: 1500 means stop, above 1500 it turns clockwise, and below it turns counterclockwise. The further the value deviates from 1500, the faster the speed.

️ Code snippet:

# Servo; void setup() { .(9); } void loop() { .(1600); // Slowly rotate clockwise delay(3000); .(1400); // Slowly rotate counterclockwise delay(3000); }

Did you see that? With just a few lines of code, your servo will be able to rotate continuously. If you are using a Raspberry Pi or other control board, the principle is the same. Just output a 50Hz PWM signal and adjust the duty cycle.

How to wire the continuous rotation servo

In terms of wiring, the 360-degree servo is exactly the same as the ordinary servo, with no new tricks. There are generally three wires: red for power (5V or 6V, depending on the servo model), brown or black for ground, and orange or yellow for signal wires. You just need to connect it to the PWM pin of the control board.

️ There is a small caveat to remind you: the current when the servo is started is quite large. If the power supply is not strong enough, it may cause the control board to restart. Especially when using 5V direct power supply, the rotation may be unstable. The best way is to power the servo separately and connect the negative terminal of the power supply to the ground of the control board. This is both stable and safe, especially when you bring multiple servos at the same time.

What is the use of 360 degree rotation of the servo?

This function is very useful in actual projects. The most common one is to make a robot car. Two 360-degree servos are installed on both sides of the chassis. By controlling their speed and direction, they can move forward, backward and turn. It is much simpler than using a DC motor and an encoder, and the control code is also shorter.

In addition to the trolley, you can also use it to make automatic curtains - install the servo on one end of the curtain rod and turn it forward and reverse to open and close the curtains. Or make a rotating display stand, put the product on it and rotate it slowly, which is particularly effective for shooting videos. Some makers also use it to make automatic feeders, revolving door models, waist joints for robotic arms, etc. It can come in handy as long as the scene requires continuous rotation.

What should you pay attention to when modifying the steering gear?

There are a few key points that need to be thought through before modification. First of all, the modified servo loses its angle positioning function. If you need to control the position accurately, you can still use an ordinary servo. Secondly, the potentiometer must be fixed at the midpoint during modification, otherwise the servo will keep turning in one direction and not stop. You can use hot melt glue or AB glue to stick it on.

In addition, not all servos are suitable for modification. The internal space of the miniature 9-gram servo is too small and it is difficult to modify. The high-torque metal tooth servo is easier to modify and more durable. When buying a servo, you can check the reviews to see if anyone has successfully modified it. One final reminder, modification will void the warranty. If you don’t want to bother, you can just buy the finished 360-degree continuous rotating servo, which will cost more than ten yuan more than the ordinary one, saving time and effort.

Do you have any servos on hand that are gathering dust? What interesting projects do you plan to use it for? Let’s chat in the comment area~