Micro Servo Eq How To Choose The Small Joint Motor Necessary For Robot Car

When engaged in product innovation, have you ever encountered this situation: you want to make a small part move, but you find that the ordinary motor is too big, too stupid, or very troublesome to control? Especially when making robots, smart cars, or small automated devices, that critical "joint" part always gives people a headache. In fact, many times what we need is not a complex drive system, but a small, obedient "muscle" - Microservo, which is a microservo. It can accurately turn to the angle you specify, and its strength is not small. It is definitely a good helper in realizing creative ideas.

What is a microservo? What can it do?

Simply put, a micro-servo is a little guy that integrates a DC motor, reduction gear set and control circuit. You give it a signal, and it can take the output shaft to the designated position and hold it there, unlike ordinary motors that just keep turning in circles. Because of this feature, it has become a "panacea" in the field of models and robots. You can see its shadow in many places, such as the tail control of remote control aircraft, the steering wheel of smart cars, every joint of the manipulator, and even the flip mechanism of the automatic feeder at home. It's like an obedient joint that makes your product truly "alive".

How to choose a suitable micro servo model

️ First, you have to figure out how much effort your product requires. The strength of the steering gear is usually expressed as "torque", and the unit is kg·cm, which means how heavy an object can be lifted 1 cm away from the axis. If your robotic arm wants to pick up a heavy object, you need to choose a larger torque. Common micro servo torques range from 1.5kg·cm to 15kg·cm. For most small DIY projects, 2-3kg·cm is enough, such as driving a small camera gimbal.

️ Secondly, consider speed and size. Speed is generally expressed in "seconds/60 degrees", that is, how long it takes to turn a 60-degree angle, such as 0.12 seconds/60 degrees. This speed is quite suitable for a responsive robot. Then there's the size, which you have to put into your design drawings. The most common size on the market is the 9-gram servo, which is about the size of a thumb and is very space-saving. When selecting, remember to go to the brand's official website, such as the official website of or, download the specification sheet and carefully check these three parameters.

Which wire should be plugged into where during manual wiring?

When you get this little servo, you'll usually see three different colored wires coming out of it. This is the most common question asked by novices. In fact, just remember a general standard. Although there may be slight differences between different brands, in most cases, the dark wire (brown or black) is the ground wire, which is connected to the negative pole of the power supply; the middle wire (usually red) is the positive pole of the power supply, which is used to supply power; and the remaining signal wire (orange, yellow or white) is used to transmit control instructions and should be connected to the PWM output pin of your main control board (such as a Raspberry Pi). Plugging it in backwards will burn out the servo. Be sure to read the instructions before plugging it in.

Is it troublesome to use code to activate the rudder?

No hassle at all! Today's development environment is very friendly. If you use it, you only need to import a built-inServo.hlibrary, and then you can do it with one or two lines of code. For example, if you write.write(90)；the servo axis will immediately turn to the 90-degree position. Isn't it very simple? You only need to specify the angle you want to turn in the code, and the library and servo will handle the rest. By changing this angle value, you can have it slowly draw a circle, or you can have it swing back and forth quickly, creating a variety of complex action sequences.

Why does the servo I bought keep vibrating?

I've encountered this situation before, and it's quite frustrating. There are usually several reasons: First, insufficient power supply. The servo requires a lot of current at the moment of starting and turning. If your power supply output current is not enough, the voltage will be pulled down, causing the control chip to restart or the servo to vibrate. Try changing to a higher current power supply. Second, signal interference. If your signal line is too long, or there is a high-power motor running next to it, interference signals may get in. Try to separate the signal cables and power cables. Third, the mechanical structure is stuck. Check to see if there is any friction in the connecting rod driven by the output shaft of your servo. If the resistance is too high, it will vibrate.

How to maintain it in daily use to make it more durable

Even though it is a small thing, it can last a long time if you take good care of it. First of all, avoid letting it stall for a long time, such as forcing it to prevent it from turning to the target angle. At this time, the motor current is very high, and it is easy to burn out the internal gears and motor. Secondly, pay attention to the working environment. This thing is generally not waterproof, dust and moisture are its biggest enemies. If your product is going to be used outdoors, it’s a good idea to add a cover to it. Finally, if your servo has metal gears, you can occasionally check whether the gears are worn. A small drop of special grease can make it move smoother and have a longer life.

So, after listening to what I said, do you think this little thing is actually quite interesting and not so mysterious anymore? What interesting functions are you planning to use in your next creative product? Welcome to share your thoughts in the comment area. Let’s communicate together. If you find it useful, don’t forget to give it a like and share it with more friends who need it!