SG92R Micro Servo, How To Choose A Micro Servo? The Upgraded Version Of SG92R Has Stronger Torque And Is Specially Designed To Treat Small Robots That Cannot Turn.

Have you ever encountered this situation: you happily installed aservoon a DIY little robot, only to find that it either twitched in place or couldn't move the "little paw" you wanted it to lift? In fact, many times, the problem does not lie in your creativity, but in the choice of that seemingly inconspicuous "little motor" - the steering gear. Today we will specifically talk about the SG92R microservoto see if it can solve the "cannot turn" problem in your hand.

What parameters should you look for when choosing aservo?

When many people buy a servo for the first time, they instantly feel at a loss when faced with the pile of numbers. In fact, there are only two key points to grasp: torque and weight. Torque determines the weight of an object it can "lift," and weight determines whether the entire project will be too heavy for it. SG92R belongs to the 9-gram servo family, which means that it is very light in weight and is extremely suitable for weight-sensitive application scenarios such as micro-manipulators and small robot joints. It can generally provide a torque of about 1.5kg/cm, which means that a one-centimeter-long force arm can lift a weight of 1.5kg. For those small objects made of plastic parts, this kind of power is already sufficient.

What is the difference between SG92R and SG90?

This is also a common question, and many people have difficulty distinguishing the two brothers. If SG90 is regarded as a normal version, then SG92R is its "upgraded and enhanced version". The most intuitive difference between the two is reflected in the gear material. SG90 uses plastic gears, while SG92R uses metal gears. What does this mean? This means that once the robotic arm is accidentally stuck, or the load is slightly exceeded, the SG92R equipped with metal gears will most likely be able to withstand it, while the SG90 using plastic gears may be scrapped directly. Spend those few extra bucks, and you’ll get “durability” and “peace of mind”.

Let's talk about it again. This difference can also be clearly seen from actual usage scenarios. For example, in some working environments where robotic arms are frequently operated, the SG92R can run more stably and reduce the probability of failure by virtue of its metal gears. In comparison, the SG90 appears to be more fragile in the same scenario. Therefore, considering all factors, the upgrade of SG92R makes sense. It brings better experience and protection to users. The few extra dollars spent will result in more reliable performance and a more practical experience. At critical moments, a series of troubles caused by equipment failure may be avoided.

How do I connect it to my main control board?

Connecting this piece is actually very simple, so don’t be intimidated at all. It generally leads to three wires: the brown wire is connected to the negative pole of the power supply (GND), the red wire is connected to the positive pole of the power supply (usually 5V), and the orange wire is connected to the signal wire. You can plug it directly into the PWM pin of a main control board such as Raspberry Pi or ESP32. ️ Here is a little tip: If you use several servos in your project, it is recommended to prepare a separate power supply module for them. Do not draw power directly from the 5V port of the main control board. Otherwise, the current will be too large, the main control board will be easy to restart, and the project will instantly become "stiff".

How to make it rotate stably and accurately

If you want the servo to be obedient, the key is that the signal given in the program must be "clean". Micro servos like the SG92R use PWM (Pulse Width Modulation) signals to control angles. Simply put, they send pulses of different widths to tell the servos "where to turn." In the actual operation process, there are two common problems: first, the power ripple is too large, which causes the signal to jitter, and the servo will make a "sizzling" jitter sound; second, there is no time left for the servo to "get in place". It is recommended that you add a delay of tens of milliseconds every time you change the angle in the code. Do not let the command pass quickly like a machine gun fire. Leave a little time for the servo to react. In this way, the movement of the servo will become much smoother.

In addition, in practical applications, we still need to pay attention to some details. For example, it is necessary to ensure the stability of the power supply and minimize the generation of ripples. It is also very important to grasp the "in place" time of the servo. You cannot just rely on a simple delay, but also need to make appropriate adjustments according to the specific model and performance of the servo. At the same time, when writing code, pay attention to the clarity of logic to avoid confusing instructions. Only in this way can the steering gear be more stable and precise during operation and achieve the desired control effect.

Use it as a robotic arm to lift heavy objects

This is a very practical question. Taking the SG92R as an example, if you want to make a small robotic arm with three degrees of freedom, it is usually recommended that the total weight of the end effector (that is, the "claw") plus the grabbed object be controlled within 100 grams. Because the mechanical arm has a "torque amplification" effect, the farther the joint is from the base, the longer the moment arm it bears. You can use the SG92R on joints near the ends, such as at the wrist or fingers. If the base requires large torque, you can consider changing to a larger servo, or use two SG92Rs in parallel to share the weight.

How to avoid pitfalls when buying

There are many good and bad SG92Rs on the market now, and there are many cases of “plastic gears pretending to be metal gears” after buying them. Let me teach you a simple identification method: don’t rush to connect the wiring after you get it. Gently move the steering wheel with your hands to feel the damping inside. The damping of metal gears is more solid, and there is a delicate metal meshing feeling when rotating; plastic gears feel more "empty" and stiff. In addition, try to choose merchants that dare to take apart the "metal gears" for you to see in the details page, or go to some reputable maker malls to buy them. Don't plant hidden dangers for the project just to save a few dollars.

After reading this, are you already planning to upgrade your little robot with SG92R? What creative project would you most like to use it for, be it a bionic palm, a mini gimbal, or something else interesting? Welcome to share your ideas in the comment area, and let’s turn your ideas into reality together.