What about YPMFG MG90S metal gear servo? Micro Servo Buying Guide

1. Core parameters and product positioning (must read)

YPMFG MG90S, a 9-gram micro servo servo, has the following core specifications:

The size specification is 22.8 times 12.2, and the result is then multiplied by 28.5 mm. This size is the same as the SG90 and can be directly replaced.

weight: About 13.4g (including wire and rocker arm)

Working voltage: 4.8V~6.0V (5V is the optimal performance point)

Twisting force: 2.0kgcm @ five volts (far more than the 1.8kgcm of the plastic gear version).

speed:0.1 sec/60° @ 5V

1. The material of the gear is all metal, 2. Generally it is made of copper teeth or alloy steel teeth, 3. Pay special attention to, 4. Some lower-priced imitations use gold-plated iron teeth, 5. The genuine YPMFG products use real copper teeth.

Dead zone setting:5 microseconds

The product is positioned as a micro servo. It has the characteristics of low to medium torque and high response speed. It is suitable for robot joints, small robotic arms, servo platforms, remote control models (such as 1/18 car models, small fixed wings) and other scenarios that require frequent movements or medium loads. Compared with the SG90, its metal gears solve the core pain point of plastic gears that tend to sweep when stressed.

2. Why choose metal gears? Real case comparison

A common situation is that user A uses a plastic gear servo, like the SG90, to drive the gripper of a small robotic arm. After continuous grabbing operations reach 100 times, the servo becomes stuck. After disassembly, it was found that the root of the output gear was completely broken. The fundamental reason is that the impact resistance and fatigue resistance of plastic gears are insufficient. Under repeated emergency stops and reverse loads, the stress on the tooth root is concentrated and leads to fracture.

After upgrading to the YPMFG MG90S metal gear version, under the same test conditions, it was continuously grasped 2,000 times without any tooth surface wear or broken teeth. Its core reaction is valuable. The yield strength of metal gears is about 5 to 8 times that of ordinary plastics. It also has the characteristics of self-lubrication, which is suitable for long-term and even high-frequency action environments.

Note that metal gears are not useful in all situations. If the load torque exceeds 2.3kg·cm for a long time, such as forcibly turning the stopped servo arm, it may cause the motor to burn out due to overload, or the gear shaft to bend. The correct approach is to leave 20% torque margin for the steering gear, that is, the actual load should not exceed 1.6kg·cm.

3. Standard procedures for installation and wiring (zero-failure operation guide)

Take the following steps to ensure your YPMFG MG90S is installed correctly and avoid common errors:

1. Confirm the power supply capability: the current of a single MG90S in a 5V locked-rotor state is about 700mA. When three of them operate at the same time, a BEC of at least 2A is required, which is a voltage stabilizing module.. If you use a development board such as Arduino to provide power directly, it will cause a reset.

2. The connection of the signal lines is as follows, the brown line is GND, the red line is VCC, and the orange line is the signal. Never connect the red wire to the signal port, otherwise the internal driver chip will be burned.

3. The trick for installing the rocker arm is to first send a neutral pulse (1500μs) to the servo, then install the rocker arm at a 90-degree angle, and finally tighten the screws. A common error is that if the rocker arm is manually moved to reach the middle position before installation, it will cause a deviation in the middle position, with a deviation of ±10 degrees.

4. Regarding the lubrication of metal gears, lithium-based grease has been pre-installed when leaving the factory, and no additional addition is required. If you need to reapply after disassembling and opening it, you can only use plastic-compatible grease, such as molybdenum disulfide. It is strictly forbidden to use ordinary butter containing acidic ingredients.

4. Quick answers to 5 high-frequency questions (Q/A format)

Q1: Can the rocker arms of MG90S and SG90 be used interchangeably?

(1) As for A, it is a completely universal situation. (2) The specifications of the output teeth of the two are consistent. (3) Specifically, it has 21 teeth and a diameter of 5.5mm. (4) Based on such specifications, the rocker arm and fixing screws can be directly interchanged.

Q2: Will the Metal Gear version consume more power?

A: The no-load current is basically flat, its value is 200mA. When under load, because the transmission efficiency is slightly higher, the actual power consumption is about 5% to 10% lower than the plastic version.。

Q3: What should I do if the servo is shaking or out of control?

First, check whether the power supply is insufficient, and then test the signal line contact. Ninety percent of the jitter is caused by the voltage being lower than 4.5V.

Q4: Can it be powered directly by a 6.6V lithium iron battery?

A: No. Its maximum withstand voltage is 6.0V, exceeding this voltage will cause the MOSFET to breakdown. Be sure to use a step-down module, or choose an alternative model that supports high voltage.

Q5: How long will it take for continuous operation before it overheats?

A: When the room temperature is 25°C, the temperature of the shell reaches 55°C after 30 minutes of reciprocating motion at a frequency of 0.2Hz. In this case, it is recommended to perform forced heat dissipation or use it intermittently.

5. Model selection comparison: When is MG90S not the best choice?

In order to help you make accurate decisions, the table presented below compares the applicable scenarios of YPMFG MG90S and other common micro servos. It only gives the differences in specifications and is not related to the brand, as follows:

The result is that MG90S has 9 grams of torque, which is the best solution in terms of cost balance. However, do not use it across levels.

6. Authenticity identification and life extension skills

There are many counterfeit YPMFG MG90S on the market. The so-called metal gears are actually iron teeth, that is, those with copper plating on the surface. The identification method is as follows:

1. Magnet test: Genuine copper teeth are non-magnetic, while iron teeth have an obvious sense of adsorption.

2. weight difference: The copper-toothed version is about 13.4g, and the iron-toothed version is only 12.1g.

3. operating noise: Copper teeth have a low and even sound, while iron teeth have sharp high frequencies and are prone to vibration.

3 suggestions for action to extend your life：

In order to avoid overvoltage damage, a dedicated voltage stabilizing protection module with a 5.1V/1A rating must be installed for each steering gear. The cost of this module is about 3 yuan.

Actively calibrate the center position during program initialization to avoid mechanical hard limits.

After every fifty hours of operation, remove the bottom cover and remove the carbon brush powder (by blowing with compressed air). This can extend the life of the motor to more than twice.

7. Summary and final action suggestions

Let me reiterate the core point again: The YPMFG MG90S metal gear micro servo device is the most direct and obvious solution to the pain point of "plastic gear teeth sweeping" in the current 9-gram servo category. However, when it is used, it needs to be operated strictly according to the voltage and load range.. Never allow it to operate with a voltage exceeding 6.0V, nor allow it to operate with a torque exceeding 2kg·cm for a long period of time.

action checklist：

[ ] Confirm that your load torque is ≤1.6kg·cm (safety margin)

[ ] Use 5V regulated power supply, peak capacity ≥ 1A per servo

[ ] Use a magnet to test the authenticity of the gear before installation

[ ] Set the software limit in the program (angle ≤ 170°)

If you are designing a mechanism that requires 100,000 cycles of action, then please consider upgrading to a 25-gram dual-bearing servo; if it is a daily DIY or model project, YPMFG MG90S will be an economical and reliable choice. Immediately follow the steps in Section 3 of this article to install it. It can be successfully completed in one go and avoid rework.