TECHNICAL SUPPORT
Published 2026-03-15
Playing with robotservos may seem simple at first glance, but after a deeper understanding, you will find that there are many ways to do it. If the wrongservomodel is selected, the position is misaligned during installation, or there is a problem with the power supply, the consequences cannot be underestimated. If it is mild, the robot will just lie down and stop moving; if it is serious, it may even burn out the steering gear, and even worse, it may cause a safety accident. Many friends who have just entered this field have suffered in these aspects.
Today, based on the experience accumulated over the years, I will talk to you about the details that must be paid attention to when using the steering gear. The content covers everything from how to choose a suitable steering gear, how to install it correctly, how to ensure stable power supply, how to accurately control, etc., and explains it clearly to everyone at once, helping everyone avoid detours when using the steering gear.
Choosing aservois like choosing joints for a robot. Strength and flexibility must be properly matched. First, you need to check the torque, whose unit is generally kg·cm, which means the weight that can be pulled when the moment arm is 1 cm. You need to accurately estimate the weight and movement speed of each joint of the robot, just like estimating the torque required to lift an arm, and then select a servo that is 20% larger than the calculated value to leave enough margin to prevent burnout. The speed depends on the no-load speed, such as 0.12 seconds/60 degrees. The faster the speed, the more responsive it will be.
In addition, when considering the steering gear, many factors need to be considered. In addition to torque and speed, the accuracy and stability of the steering gear cannot be ignored. The high-precision steering gear can more accurately control the rotation angle of the robot's joints and ensure the accuracy of the movement. A steering gear with good stability can maintain good working condition during long-term operation and reduce errors caused by jitter or deviation. These factors are interrelated and jointly affect the overall performance of the robot. Therefore, when selecting a steering gear for the robot, it is necessary to comprehensively weigh and make careful decisions to ensure that the robot can complete various tasks efficiently and stably.
In addition to torque speed, it also depends on the type. Analog servos are cheap, but will have silent zones and jitter; digital servos have fast response, accurate positioning, are suitable for precision control, and are slightly more expensive. In addition, pay attention to the steering angle range. Standard servos are generally 180 degrees. When making wheels, continuous rotating servos are required. Be sure to read the parameters clearly before buying, and don’t buy the wrong one.
When installing the steering gear, fixing it firmly is the first principle. Tighten it to the bracket with the matching screws. Don't use hot melt glue as it will loosen after a few vibrations. Leave enough space at the installation location to ensure that the steering wheel does not hit cables or other structures when rotating. The wiring should be straightened out and fixed with cable ties to avoid wire wear and short circuit during movement, which is a common failure point.
Also pay attention to the installation direction. Some servos are installed in the opposite direction, which will cause the control direction to be reversed. It is best to connect the signal line and turn it manually to confirm that the direction of rotation is in line with your design before final fixing. The steering wheel must also be matched, the splines must be aligned, and the jackscrew must be tightened to prevent slipping and idling.
The servo is very picky about the power supply. If the voltage is unstable or the current is not enough, it will vibrate and become weak. Most servos operate at a voltage of 4.8V to 6V, and the power supply depends on your servo specifications. A margin should be left in the current calculation. The instantaneous current when multiple servos are started at the same time is very large, and the battery discharge capacity must keep up. It is recommended to use a 2S lithium battery or an independent BEC for power supply.
There are many particularities in power wiring. First, the wire diameter must be thick enough to reduce line voltage drop. Secondly, it is best to connect a large capacitor in parallel to both ends of the power supply, such as a 1000μF capacitor, which can effectively filter out ripple and stabilize the voltage. At the same time, be sure to keep in mind that the control board power supply and servo power supply need to be set separately to avoid the large current generated by the servo from interfering with the control signal. In addition, the positive and negative poles must not be connected reversely. Once they are connected reversely, there will be a high probability of smoke, so adding an anti-reverse connection diode will be safer.
The steering gear is controlled by PWM (Pulse Width Modulation) signals, and different pulse widths correspond to different angles. The standard is a 20ms cycle and a pulse width of 0.5ms to 2.5ms corresponding to 0 to 180 degrees, but there are differences between brands, so be sure to read the instructions. When using a microcontroller to generate PWM, make sure the timer is accurate, otherwise the angle will be off.
The control signal lines should be as short as possible and kept away from high current lines to avoid electromagnetic interference. If you find that the servo is shaking slightly, in addition to checking the power supply, you should also check whether the PWM signal is stable and whether there is any clutter. When controlling multiple servos, make sure that the signal lines of each servo can be controlled independently and cannot send the same signal together unless you want them to perform the same action.
Overheating is the number one killer of servos. If the rotor is blocked for a long time or the load is too large, the internal motor will generate serious heat if the current continues to be high. Once the robot is found to be stuck, immediately cut off the power and check. When designing the mechanical structure, avoid having the steering gear work at its extreme position and leave some margin for movement.
Heat dissipation measures must be taken. Metal-cased servos dissipate heat better than plastic ones. If necessary, install small heat sinks. Control the working cycle of the servo. Don't let it run at full load continuously. You can add a short pause in the program to let it "take a breath." If you touch the servo shell with your hands and it feels hot (over 60 degrees), be careful. Long-term high temperature will demagnetize and burn the circuit.
If you want your servo to last a long time, routine maintenance is crucial. Regularly check the outside of the servo and use a soft-bristled brush to clean away dust, especially the cooling holes and gaps. Check whether the cable is damaged and whether the plug is loose or oxidized. These poor connections will cause intermittent signals.
Moving parts must be lubricated. Apply a drop of lubricating oil at the contact point between the steering gear output shaft and the steering wheel to reduce mechanical wear. The storage environment should be dry to prevent moisture from corroding the circuit board. If not used for a long time, remember to remove the battery to prevent leakage. Before each use, simply test whether the rotation is smooth. If there is any abnormal noise or jamming, deal with it in time. Don't wait for the problem to become serious before repairing it.
Have you ever encountered any weird and crazy problems when using the servo? Come to the comment area to chat about your experiences, and let’s avoid pitfalls together. If you find the article useful, please give it a like and share it with more friends who play robots!
Update Time：2026-03-15
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