TECHNICAL SUPPORT
Published 2026-03-19
Have you ever encountered this situation? I was full of joy in designing a robot arm or a reconnaissance car, but the space was tight. However, I found that the ordinary micro steering gear was too soft to carry the load at all. It was clear that there was just a little bit of effort, but the whole project got stuck. Don't worry, today we will talk about how to solve this problem of "small body but big strength".
When choosing this kind ofservo, the first step is not to look at the brand, but to look at the "torque" item in the parameters, which is usually in kg·cm. This represents how many kilograms of weight it can pull 1 cm away from the axis of rotation. You have to first estimate how much force your mechanism needs, and then leave at least 20% margin to ensure that it works effortlessly.
In addition to torque, you also have to pay attention to its size and weight. The reason why microservos are called micro is to fit into a compact space. Common ones on the market include 9gservos, but there are high-torque versions that are slightly larger, such as 15g or even 20g. You have to confirm whether the battery compartment and fixed position of your device can accommodate this "little Hercules".
Many friends will find that most high-torque micro servos are labeled "metal gears." This is not to sound fancy, but plastic gears can easily "snap" or simply fall apart under high torque. If you switch to metal gears, especially steel gears, the wear resistance and impact resistance will be improved to a higher level, and they can be used for a long time.
Another hidden benefit of using a metal servo is that its virtual position is usually smaller. Because the machining accuracy of metal gears can be higher and the meshing clearance is smaller, when you give it a command to stop at a position, it can stop more accurately and shake less. This will provide a much better experience for manipulators or gimbals that require precise positioning.
There is actually a simple estimation method for this, and no complicated formulas are required. You can simulate this with a ruler and measure the distance (in centimeters) from the center of the servo shaft to the contact point where you want to push the object. Then estimate how much force (in kilograms) it takes to push that object. Multiply these two numbers together and you get the theoretical torque you need.
For example, if your servo wants to push a 5 cm long connecting rod to lift a 0.5 kg object, then the theoretical torque is 5 times 0.5, which is equal to 2.5 kg·cm. At this time, if you choose a servo with a nominal torque of 2.5, it can only barely lift. Considering friction and speed, I suggest you directly choose a 3.5 or even 4 kg·cm one so that you can use it calmly.
When installing this type of steering gear, the fixing screws must be tightened! Because it is powerful, the impact force when starting and stopping is also large. If it is not fixed properly, it can easily crack the mounting holes or cause the screws to loosen. It is best to add a little screw glue to prevent it from loosening during long-term vibration. The connection between the steering wheel and the connecting rod must also be tight without any slack.
When debugging, don't put a large load on it as soon as you start it. Let it rotate left and right without load first, and listen for any abnormal noise or lag. Then gently hold the steering wheel with your fingers and feel whether its stalling torque is consistent with the parameter description. Finally, load the test step by step to see whether its response is linear under different pulse width signals and whether there is any jitter or serious heating.
Of course it is important, especially if your servo is going to be used in places that require fine movements. Control accuracy is usually related to the quality of the potentiometer inside the servo and the control board algorithm. With a high-precision servo, if you ask it to turn 1 degree, it will really only turn 1 degree and will not wobble a few more times. This difference is obvious when debugging the camera gimbal or bionic finger.
If your project is just a simple switch action, such as controlling a landing gear, a slightly lower accuracy is acceptable. But if you are doing closed-loop control or need to follow a specific trajectory, you must choose one with high accuracy. You can look at the stability of the "dead zone" or "no-load speed" in the servo parameters, which can reflect its control level.
It is so convenient to buy things online now, but the quality is also varied. Some cheap servos have a large nominal torque, but they are not practical at all and even cause serious heat. My experience is to try to find manufacturers that have their own official website and technical background, and don’t just focus on the low-priced models in C stores. You can search for "servo" or similar brands and look at their official website.
Once you find the product you like, don’t rush to place an order. First go to the official website to download its technical manual and see if there are detailed dimensional drawings, line sequence definitions and PWM control ranges. If these information are very standardized, it means that the manufacturer is very professional. At this time, purchase through official website channels or authorized dealers. The quality and after-sales service are guaranteed, and the project can be implemented steadily.
When you were working on a project, have you ever overturned your car because you chose the wrong servo? Welcome to share your pitfall experiences in the comment area, so that everyone can avoid lightning! If you find this article useful, don’t forget to like it and share it with more friends who play robots.
Update Time：2026-03-19
Contact Kpower's product specialist to recommend suitable motor or gearbox for your product.
