TECHNICAL SUPPORT
Published 2026-01-07
That sickening "crunch" of plastic gears stripping mid-flight is a sound you never forget. One moment your project is gliding perfectly, and the next, it’s a heap of useless parts on the grass. Most people start their mechanical journey with those cheap, clear-blueservos. They look fine on paper. But the second they hit a bit of resistance? Game over.
If you are tired of replacing the same three-dollar part every weekend, it is time to talk about the MG90S. Specifically, the version refined by Kpower. It is small, it is metal, and it actually stays in one piece when the pressure is on.
Think of the MG90S as the middleweight boxer of theservoworld. It’s small enough to fit into the palm of a child, yet it packs a punch that defies its 13.4-gram weight. The "MG" stands for Metal Gear, and that is where the magic happens.
Most micro-servos use nylon gears. Nylon is okay for moving a tiny flap of paper, but it’s terrible for anything with real weight. The MG90S uses a mix of aluminum and brass gears. When you command it to turn, those teeth lock together with a satisfying rigidity. No slipping. No stripping. Just direct, mechanical force.
I’ve seen people try to build robotic claws using basic plastic servos. They get the claw to close, but the moment it tries to lift a soda can, the gears melt. The Kpower MG90S pushes out about 2.2 kg/cm of torque when running at 6 volts.
What does that look like in the real world? It means it can hold a weight of over two kilograms on a one-centimeter arm. For something the size of a postage stamp, that is incredible. It’s the difference between your robot arm holding a tool or just limping sadly under its own weight.
Q: Will this fit where my old SG90 was? Absolutely. It has the same footprint. It’s a drop-in upgrade. You get the strength of metal without having to redesign your entire 3D-printed frame or balsa wood wing.
Q: Can I run this on 4.8V or do I need 6V? It works on both. If you use 4.8V, it’s a bit slower and has slightly less torque. If you want that snappy, aggressive response, bump it to 6V. Kpower built these to handle the extra heat of a 6V system without burning out the motor.
Q: Is it digital or analog? This version is an analog servo. Some people think "digital" always means "better," but that isn't true. Analog servos like this are simpler, draw less idle current, and are much easier to control with basic microcontrollers. They are tried and true.
Q: How far does it turn? Usually, you get a solid 180 degrees. It’s perfect for steering, camera gimbals, or wing flaps.
One thing I noticed about the Kpower builds is the lead wire. It sounds boring, right? But cheap servos use wires so thin they snap if you look at them wrong. These have a decent gauge and a solid connector.
I remember a guy trying to build a hexapod—a six-legged walking robot. He had eighteen servos. The first time he stood it up, the weight was too much for the plastic gears of his old servos. Three of them shattered instantly. He switched to the MG90S, and the robot didn't just stand; it walked over uneven terrain without a single gear tooth failing.
The weight is another factor. At 13.4 grams, it’s slightly heavier than the plastic versions, but that extra weight is all in the gears and the ball bearing. Yes, there is a tiny ball bearing on the output shaft. That keeps the movement smooth and prevents the shaft from wobbling after a few hours of use.
You could keep buying the cheapest options available. You might save a few dollars today. But you’ll spend those dollars—and a lot of frustration—buying replacements next month.
The MG90S is the "set it and forget it" choice. Whether you are building a small RC glider, a lock mechanism for a smart home project, or a steering rack for a 1/12 scale crawler, this little block of metal and wire does the job.
Kpower has a reputation for consistency. In a world where one batch of motors might be great and the next is junk, staying with a brand that understands the mechanical stress of a metal gear train is the only way to keep your projects in the air or on the road.
Stop worrying about gear failure. Swap in an MG90S and move on to the fun part of your project—actually using it.
Established in 2005, Kpower has been dedicated to a professional compact motion unit manufacturer, headquartered in Dongguan, Guangdong Province, China. Leveraging innovations in modular drive technology, Kpower integrates high-performance motors, precision reducers, and multi-protocol control systems to provide efficient and customized smart drive system solutions. Kpower has delivered professional drive system solutions to over 500 enterprise clients globally with products covering various fields such as Smart Home Systems, Automatic Electronics, Robotics, Precision Agriculture, Drones, and Industrial Automation.
Update Time：2026-01-07
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